LogTape 1.1.0 is here, and it focuses on making your logging smarter and more flexible. This release introduces two major features we think you'll love.
Introducing fingers crossed logging
Tired of noisy production logs? Wish you had the full story when an error finally pops up? Our new “fingers crossed” logging pattern was built for exactly that.
With fingers crossed logging, LogTape buffers your debug and low-level logs in memory instead of immediately outputting them. When an error occurs, it flushes the entire buffer—giving you the complete sequence of events leading up to the problem. Once the error is logged, subsequent logs pass through normally until the next trigger event.
import { configure, fingersCrossed, getConsoleSink } from "@logtape/logtape";await configure({ sinks: { console: fingersCrossed(getConsoleSink(), { triggerLevel: "error", // Buffer until an error occurs maxBufferSize: 500, // Keep last 500 records }), }, loggers: [ { category: [], sinks: ["console"], lowestLevel: "debug" }, ],});
It's the best of both worlds: clean logs when things are running smoothly, and rich, detailed context the moment an issue occurs. Stop choosing between too much noise and not enough information.
Category isolation for complex applications
For applications with multiple modules or services, the new category isolation feature prevents one component's errors from flushing unrelated logs:
fingersCrossed(getConsoleSink(), { isolateByCategory: "descendant", // Only flush related categories})
You can choose how categories relate to each other—flush child categories when a parent triggers, parent categories when a child triggers, or both. This surgical precision keeps your logs focused and relevant.
Direct log emission for external systems
Integrating logs from external systems just got a lot easier. With the new Logger.emit() method, you can now feed logs from Kafka, legacy applications, or any other source directly into LogTape while preserving their original timestamps and metadata.
const logger = getLogger(["my-app", "integration"]);// Preserve the original timestamp from an external systemlogger.emit({ timestamp: kafkaMessage.originalTimestamp, level: "info", message: [kafkaMessage.content], rawMessage: kafkaMessage.content, properties: { source: "kafka", partition: kafkaMessage.partition, offset: kafkaMessage.offset, },});
This new low-level API gives you full control over the log record, allowing you to leverage LogTape's powerful filtering, formatting, and sink ecosystem for any log source. It's particularly valuable for:
Migrating from other logging systems while preserving historical context
Aggregating logs from multiple sources with accurate timestamps
Building custom adapters for specialized logging scenarios
Bug fixes and improvements
Beyond the headline features, we've strengthened LogTape's reliability across the ecosystem. Check out the full changelog for complete details.
@logtape/file
Fixed potential data loss during high-volume logging by ensuring all buffered logs are fully written before disposal
Changed getStreamFileSink() to properly implement AsyncDisposable for cleaner resource management
@logtape/sentry
Improved cross-runtime compatibility by introducing a structural interface that avoids type conflicts
Fixed template metadata preservation for better Sentry breadcrumb formatting
Removed unnecessary Node.js dependencies for broader runtime support
@logtape/pretty
Added support for displaying structured data properties directly in pretty-formatted output (thanks to Matthias Feist for the contribution)
Why upgrade?
Upgrading to 1.1.0 is a no-brainer. It's fully backward-compatible and makes your setup more powerful. The fingers crossed feature alone will change how you debug in production. Imagine getting a complete stack trace with full context for every error, without the performance hit of constant verbose logging.
If you're new to LogTape, this release shows what we're all about: building tools that solve real-world problems. We don't think you should have to choose between noisy logs and insufficient context. LogTape adapts to what you need, buffering logs when things are quiet and providing rich detail when it matters most.
The new features are opt-in, so your existing configuration continues working exactly as before. When you're ready, explore fingers crossed logging for cleaner production logs or use emit() for advanced integration scenarios.
Let us know what you think of the new features! We're always active in our GitHub discussions and would love to hear your feedback.
LogTape 1.1.0 is here, and it focuses on making your logging smarter and more flexible. This release introduces two major features we think you'll love.
Introducing fingers crossed logging
Tired of noisy production logs? Wish you had the full story when an error finally pops up? Our new “fingers crossed” logging pattern was built for exactly that.
With fingers crossed logging, LogTape buffers your debug and low-level logs in memory instead of immediately outputting them. When an error occurs, it flushes the entire buffer—giving you the complete sequence of events leading up to the problem. Once the error is logged, subsequent logs pass through normally until the next trigger event.
import { configure, fingersCrossed, getConsoleSink } from "@logtape/logtape";await configure({ sinks: { console: fingersCrossed(getConsoleSink(), { triggerLevel: "error", // Buffer until an error occurs maxBufferSize: 500, // Keep last 500 records }), }, loggers: [ { category: [], sinks: ["console"], lowestLevel: "debug" }, ],});
It's the best of both worlds: clean logs when things are running smoothly, and rich, detailed context the moment an issue occurs. Stop choosing between too much noise and not enough information.
Category isolation for complex applications
For applications with multiple modules or services, the new category isolation feature prevents one component's errors from flushing unrelated logs:
fingersCrossed(getConsoleSink(), { isolateByCategory: "descendant", // Only flush related categories})
You can choose how categories relate to each other—flush child categories when a parent triggers, parent categories when a child triggers, or both. This surgical precision keeps your logs focused and relevant.
Direct log emission for external systems
Integrating logs from external systems just got a lot easier. With the new Logger.emit() method, you can now feed logs from Kafka, legacy applications, or any other source directly into LogTape while preserving their original timestamps and metadata.
const logger = getLogger(["my-app", "integration"]);// Preserve the original timestamp from an external systemlogger.emit({ timestamp: kafkaMessage.originalTimestamp, level: "info", message: [kafkaMessage.content], rawMessage: kafkaMessage.content, properties: { source: "kafka", partition: kafkaMessage.partition, offset: kafkaMessage.offset, },});
This new low-level API gives you full control over the log record, allowing you to leverage LogTape's powerful filtering, formatting, and sink ecosystem for any log source. It's particularly valuable for:
Migrating from other logging systems while preserving historical context
Aggregating logs from multiple sources with accurate timestamps
Building custom adapters for specialized logging scenarios
Bug fixes and improvements
Beyond the headline features, we've strengthened LogTape's reliability across the ecosystem. Check out the full changelog for complete details.
@logtape/file
Fixed potential data loss during high-volume logging by ensuring all buffered logs are fully written before disposal
Changed getStreamFileSink() to properly implement AsyncDisposable for cleaner resource management
@logtape/sentry
Improved cross-runtime compatibility by introducing a structural interface that avoids type conflicts
Fixed template metadata preservation for better Sentry breadcrumb formatting
Removed unnecessary Node.js dependencies for broader runtime support
@logtape/pretty
Added support for displaying structured data properties directly in pretty-formatted output (thanks to Matthias Feist for the contribution)
Why upgrade?
Upgrading to 1.1.0 is a no-brainer. It's fully backward-compatible and makes your setup more powerful. The fingers crossed feature alone will change how you debug in production. Imagine getting a complete stack trace with full context for every error, without the performance hit of constant verbose logging.
If you're new to LogTape, this release shows what we're all about: building tools that solve real-world problems. We don't think you should have to choose between noisy logs and insufficient context. LogTape adapts to what you need, buffering logs when things are quiet and providing rich detail when it matters most.
The new features are opt-in, so your existing configuration continues working exactly as before. When you're ready, explore fingers crossed logging for cleaner production logs or use emit() for advanced integration scenarios.
Let us know what you think of the new features! We're always active in our GitHub discussions and would love to hear your feedback.
LogTape 1.1.0 is here, and it focuses on making your logging smarter and more flexible. This release introduces two major features we think you'll love.
Introducing fingers crossed logging
Tired of noisy production logs? Wish you had the full story when an error finally pops up? Our new “fingers crossed” logging pattern was built for exactly that.
With fingers crossed logging, LogTape buffers your debug and low-level logs in memory instead of immediately outputting them. When an error occurs, it flushes the entire buffer—giving you the complete sequence of events leading up to the problem. Once the error is logged, subsequent logs pass through normally until the next trigger event.
import { configure, fingersCrossed, getConsoleSink } from "@logtape/logtape";await configure({ sinks: { console: fingersCrossed(getConsoleSink(), { triggerLevel: "error", // Buffer until an error occurs maxBufferSize: 500, // Keep last 500 records }), }, loggers: [ { category: [], sinks: ["console"], lowestLevel: "debug" }, ],});
It's the best of both worlds: clean logs when things are running smoothly, and rich, detailed context the moment an issue occurs. Stop choosing between too much noise and not enough information.
Category isolation for complex applications
For applications with multiple modules or services, the new category isolation feature prevents one component's errors from flushing unrelated logs:
fingersCrossed(getConsoleSink(), { isolateByCategory: "descendant", // Only flush related categories})
You can choose how categories relate to each other—flush child categories when a parent triggers, parent categories when a child triggers, or both. This surgical precision keeps your logs focused and relevant.
Direct log emission for external systems
Integrating logs from external systems just got a lot easier. With the new Logger.emit() method, you can now feed logs from Kafka, legacy applications, or any other source directly into LogTape while preserving their original timestamps and metadata.
const logger = getLogger(["my-app", "integration"]);// Preserve the original timestamp from an external systemlogger.emit({ timestamp: kafkaMessage.originalTimestamp, level: "info", message: [kafkaMessage.content], rawMessage: kafkaMessage.content, properties: { source: "kafka", partition: kafkaMessage.partition, offset: kafkaMessage.offset, },});
This new low-level API gives you full control over the log record, allowing you to leverage LogTape's powerful filtering, formatting, and sink ecosystem for any log source. It's particularly valuable for:
Migrating from other logging systems while preserving historical context
Aggregating logs from multiple sources with accurate timestamps
Building custom adapters for specialized logging scenarios
Bug fixes and improvements
Beyond the headline features, we've strengthened LogTape's reliability across the ecosystem. Check out the full changelog for complete details.
@logtape/file
Fixed potential data loss during high-volume logging by ensuring all buffered logs are fully written before disposal
Changed getStreamFileSink() to properly implement AsyncDisposable for cleaner resource management
@logtape/sentry
Improved cross-runtime compatibility by introducing a structural interface that avoids type conflicts
Fixed template metadata preservation for better Sentry breadcrumb formatting
Removed unnecessary Node.js dependencies for broader runtime support
@logtape/pretty
Added support for displaying structured data properties directly in pretty-formatted output (thanks to Matthias Feist for the contribution)
Why upgrade?
Upgrading to 1.1.0 is a no-brainer. It's fully backward-compatible and makes your setup more powerful. The fingers crossed feature alone will change how you debug in production. Imagine getting a complete stack trace with full context for every error, without the performance hit of constant verbose logging.
If you're new to LogTape, this release shows what we're all about: building tools that solve real-world problems. We don't think you should have to choose between noisy logs and insufficient context. LogTape adapts to what you need, buffering logs when things are quiet and providing rich detail when it matters most.
The new features are opt-in, so your existing configuration continues working exactly as before. When you're ready, explore fingers crossed logging for cleaner production logs or use emit() for advanced integration scenarios.
Let us know what you think of the new features! We're always active in our GitHub discussions and would love to hear your feedback.
LogTape 1.1.0 is here, and it focuses on making your logging smarter and more flexible. This release introduces two major features we think you'll love.
Introducing fingers crossed logging
Tired of noisy production logs? Wish you had the full story when an error finally pops up? Our new “fingers crossed” logging pattern was built for exactly that.
With fingers crossed logging, LogTape buffers your debug and low-level logs in memory instead of immediately outputting them. When an error occurs, it flushes the entire buffer—giving you the complete sequence of events leading up to the problem. Once the error is logged, subsequent logs pass through normally until the next trigger event.
import { configure, fingersCrossed, getConsoleSink } from "@logtape/logtape";await configure({ sinks: { console: fingersCrossed(getConsoleSink(), { triggerLevel: "error", // Buffer until an error occurs maxBufferSize: 500, // Keep last 500 records }), }, loggers: [ { category: [], sinks: ["console"], lowestLevel: "debug" }, ],});
It's the best of both worlds: clean logs when things are running smoothly, and rich, detailed context the moment an issue occurs. Stop choosing between too much noise and not enough information.
Category isolation for complex applications
For applications with multiple modules or services, the new category isolation feature prevents one component's errors from flushing unrelated logs:
fingersCrossed(getConsoleSink(), { isolateByCategory: "descendant", // Only flush related categories})
You can choose how categories relate to each other—flush child categories when a parent triggers, parent categories when a child triggers, or both. This surgical precision keeps your logs focused and relevant.
Direct log emission for external systems
Integrating logs from external systems just got a lot easier. With the new Logger.emit() method, you can now feed logs from Kafka, legacy applications, or any other source directly into LogTape while preserving their original timestamps and metadata.
const logger = getLogger(["my-app", "integration"]);// Preserve the original timestamp from an external systemlogger.emit({ timestamp: kafkaMessage.originalTimestamp, level: "info", message: [kafkaMessage.content], rawMessage: kafkaMessage.content, properties: { source: "kafka", partition: kafkaMessage.partition, offset: kafkaMessage.offset, },});
This new low-level API gives you full control over the log record, allowing you to leverage LogTape's powerful filtering, formatting, and sink ecosystem for any log source. It's particularly valuable for:
Migrating from other logging systems while preserving historical context
Aggregating logs from multiple sources with accurate timestamps
Building custom adapters for specialized logging scenarios
Bug fixes and improvements
Beyond the headline features, we've strengthened LogTape's reliability across the ecosystem. Check out the full changelog for complete details.
@logtape/file
Fixed potential data loss during high-volume logging by ensuring all buffered logs are fully written before disposal
Changed getStreamFileSink() to properly implement AsyncDisposable for cleaner resource management
@logtape/sentry
Improved cross-runtime compatibility by introducing a structural interface that avoids type conflicts
Fixed template metadata preservation for better Sentry breadcrumb formatting
Removed unnecessary Node.js dependencies for broader runtime support
@logtape/pretty
Added support for displaying structured data properties directly in pretty-formatted output (thanks to Matthias Feist for the contribution)
Why upgrade?
Upgrading to 1.1.0 is a no-brainer. It's fully backward-compatible and makes your setup more powerful. The fingers crossed feature alone will change how you debug in production. Imagine getting a complete stack trace with full context for every error, without the performance hit of constant verbose logging.
If you're new to LogTape, this release shows what we're all about: building tools that solve real-world problems. We don't think you should have to choose between noisy logs and insufficient context. LogTape adapts to what you need, buffering logs when things are quiet and providing rich detail when it matters most.
The new features are opt-in, so your existing configuration continues working exactly as before. When you're ready, explore fingers crossed logging for cleaner production logs or use emit() for advanced integration scenarios.
Let us know what you think of the new features! We're always active in our GitHub discussions and would love to hear your feedback.
LogTape 1.1.0 is here, and it focuses on making your logging smarter and more flexible. This release introduces two major features we think you'll love.
Introducing fingers crossed logging
Tired of noisy production logs? Wish you had the full story when an error finally pops up? Our new “fingers crossed” logging pattern was built for exactly that.
With fingers crossed logging, LogTape buffers your debug and low-level logs in memory instead of immediately outputting them. When an error occurs, it flushes the entire buffer—giving you the complete sequence of events leading up to the problem. Once the error is logged, subsequent logs pass through normally until the next trigger event.
import { configure, fingersCrossed, getConsoleSink } from "@logtape/logtape";await configure({ sinks: { console: fingersCrossed(getConsoleSink(), { triggerLevel: "error", // Buffer until an error occurs maxBufferSize: 500, // Keep last 500 records }), }, loggers: [ { category: [], sinks: ["console"], lowestLevel: "debug" }, ],});
It's the best of both worlds: clean logs when things are running smoothly, and rich, detailed context the moment an issue occurs. Stop choosing between too much noise and not enough information.
Category isolation for complex applications
For applications with multiple modules or services, the new category isolation feature prevents one component's errors from flushing unrelated logs:
fingersCrossed(getConsoleSink(), { isolateByCategory: "descendant", // Only flush related categories})
You can choose how categories relate to each other—flush child categories when a parent triggers, parent categories when a child triggers, or both. This surgical precision keeps your logs focused and relevant.
Direct log emission for external systems
Integrating logs from external systems just got a lot easier. With the new Logger.emit() method, you can now feed logs from Kafka, legacy applications, or any other source directly into LogTape while preserving their original timestamps and metadata.
const logger = getLogger(["my-app", "integration"]);// Preserve the original timestamp from an external systemlogger.emit({ timestamp: kafkaMessage.originalTimestamp, level: "info", message: [kafkaMessage.content], rawMessage: kafkaMessage.content, properties: { source: "kafka", partition: kafkaMessage.partition, offset: kafkaMessage.offset, },});
This new low-level API gives you full control over the log record, allowing you to leverage LogTape's powerful filtering, formatting, and sink ecosystem for any log source. It's particularly valuable for:
Migrating from other logging systems while preserving historical context
Aggregating logs from multiple sources with accurate timestamps
Building custom adapters for specialized logging scenarios
Bug fixes and improvements
Beyond the headline features, we've strengthened LogTape's reliability across the ecosystem. Check out the full changelog for complete details.
@logtape/file
Fixed potential data loss during high-volume logging by ensuring all buffered logs are fully written before disposal
Changed getStreamFileSink() to properly implement AsyncDisposable for cleaner resource management
@logtape/sentry
Improved cross-runtime compatibility by introducing a structural interface that avoids type conflicts
Fixed template metadata preservation for better Sentry breadcrumb formatting
Removed unnecessary Node.js dependencies for broader runtime support
@logtape/pretty
Added support for displaying structured data properties directly in pretty-formatted output (thanks to Matthias Feist for the contribution)
Why upgrade?
Upgrading to 1.1.0 is a no-brainer. It's fully backward-compatible and makes your setup more powerful. The fingers crossed feature alone will change how you debug in production. Imagine getting a complete stack trace with full context for every error, without the performance hit of constant verbose logging.
If you're new to LogTape, this release shows what we're all about: building tools that solve real-world problems. We don't think you should have to choose between noisy logs and insufficient context. LogTape adapts to what you need, buffering logs when things are quiet and providing rich detail when it matters most.
The new features are opt-in, so your existing configuration continues working exactly as before. When you're ready, explore fingers crossed logging for cleaner production logs or use emit() for advanced integration scenarios.
Let us know what you think of the new features! We're always active in our GitHub discussions and would love to hear your feedback.
LogTape 1.1.0 is here, and it focuses on making your logging smarter and more flexible. This release introduces two major features we think you'll love.
Introducing fingers crossed logging
Tired of noisy production logs? Wish you had the full story when an error finally pops up? Our new “fingers crossed” logging pattern was built for exactly that.
With fingers crossed logging, LogTape buffers your debug and low-level logs in memory instead of immediately outputting them. When an error occurs, it flushes the entire buffer—giving you the complete sequence of events leading up to the problem. Once the error is logged, subsequent logs pass through normally until the next trigger event.
import { configure, fingersCrossed, getConsoleSink } from "@logtape/logtape";await configure({ sinks: { console: fingersCrossed(getConsoleSink(), { triggerLevel: "error", // Buffer until an error occurs maxBufferSize: 500, // Keep last 500 records }), }, loggers: [ { category: [], sinks: ["console"], lowestLevel: "debug" }, ],});
It's the best of both worlds: clean logs when things are running smoothly, and rich, detailed context the moment an issue occurs. Stop choosing between too much noise and not enough information.
Category isolation for complex applications
For applications with multiple modules or services, the new category isolation feature prevents one component's errors from flushing unrelated logs:
fingersCrossed(getConsoleSink(), { isolateByCategory: "descendant", // Only flush related categories})
You can choose how categories relate to each other—flush child categories when a parent triggers, parent categories when a child triggers, or both. This surgical precision keeps your logs focused and relevant.
Direct log emission for external systems
Integrating logs from external systems just got a lot easier. With the new Logger.emit() method, you can now feed logs from Kafka, legacy applications, or any other source directly into LogTape while preserving their original timestamps and metadata.
const logger = getLogger(["my-app", "integration"]);// Preserve the original timestamp from an external systemlogger.emit({ timestamp: kafkaMessage.originalTimestamp, level: "info", message: [kafkaMessage.content], rawMessage: kafkaMessage.content, properties: { source: "kafka", partition: kafkaMessage.partition, offset: kafkaMessage.offset, },});
This new low-level API gives you full control over the log record, allowing you to leverage LogTape's powerful filtering, formatting, and sink ecosystem for any log source. It's particularly valuable for:
Migrating from other logging systems while preserving historical context
Aggregating logs from multiple sources with accurate timestamps
Building custom adapters for specialized logging scenarios
Bug fixes and improvements
Beyond the headline features, we've strengthened LogTape's reliability across the ecosystem. Check out the full changelog for complete details.
@logtape/file
Fixed potential data loss during high-volume logging by ensuring all buffered logs are fully written before disposal
Changed getStreamFileSink() to properly implement AsyncDisposable for cleaner resource management
@logtape/sentry
Improved cross-runtime compatibility by introducing a structural interface that avoids type conflicts
Fixed template metadata preservation for better Sentry breadcrumb formatting
Removed unnecessary Node.js dependencies for broader runtime support
@logtape/pretty
Added support for displaying structured data properties directly in pretty-formatted output (thanks to Matthias Feist for the contribution)
Why upgrade?
Upgrading to 1.1.0 is a no-brainer. It's fully backward-compatible and makes your setup more powerful. The fingers crossed feature alone will change how you debug in production. Imagine getting a complete stack trace with full context for every error, without the performance hit of constant verbose logging.
If you're new to LogTape, this release shows what we're all about: building tools that solve real-world problems. We don't think you should have to choose between noisy logs and insufficient context. LogTape adapts to what you need, buffering logs when things are quiet and providing rich detail when it matters most.
The new features are opt-in, so your existing configuration continues working exactly as before. When you're ready, explore fingers crossed logging for cleaner production logs or use emit() for advanced integration scenarios.
Let us know what you think of the new features! We're always active in our GitHub discussions and would love to hear your feedback.
In the diverse and ever-evolving JavaScript ecosystem, logging remains a critical component for development, debugging, and monitoring applications. While numerous logging libraries exist, LogTape stands out with its unique combination of simplicity, flexibility, and cross-runtime compatibility. Let's explore why LogTape deserves consideration for your next JavaScript or TypeScript project—whether you're building an application or a library.
Zero Dependencies: A Lightweight Footprint
One of LogTape's most compelling features is its complete absence of dependencies. In an era where “dependency hell” plagues many JavaScript projects, LogTape offers a refreshing alternative:
// No additional packages to install beyond LogTape itselfimport { configure, getConsoleSink, getLogger } from "@logtape/logtape";
This zero-dependency approach provides several advantages:
Reduced bundle size
No transitive dependencies means smaller packages
Enhanced stability
No risk of breaking changes from upstream dependencies
Simplified security
Fewer potential vulnerabilities from third-party code
Lower integration overhead
Particularly valuable for library authors who don't want to burden users with additional dependencies
Runtime Diversity: Write Once, Log Everywhere
While many popular logging libraries focus primarily on Node.js, LogTape provides seamless support across diverse JavaScript runtimes:
This runtime flexibility means you can use consistent logging patterns regardless of your deployment environment:
// Same API works seamlessly across all JavaScript runtimesimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-service", "user-management"]);// Works in Node.js, Deno, Bun, browsers, or edge functionslogger.info`User ${userId} logged in successfully`;
For teams working across multiple platforms or projects transitioning between runtimes, this consistency is invaluable. No need to learn different logging libraries or approaches—LogTape works the same way everywhere.
Hierarchical Categories: Fine-Grained Control
LogTape's hierarchical category system represents a standout feature that's surprisingly rare among JavaScript logging libraries. Categories allow you to organize logs in a tree-like structure:
This hierarchical approach offers powerful benefits:
Targeted filtering
Configure different log levels for different parts of your application
Inheritance
Child loggers inherit settings from parents, reducing configuration overhead
Organizational clarity
Logs naturally follow your application's module structure
Here's how you might configure logging levels for different categories:
await configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log"), }, loggers: [ // Base configuration for all app logs { category: ["my-app"], lowestLevel: "info", sinks: ["console", "file"] }, // More verbose logging just for database components { category: ["my-app", "database"], lowestLevel: "debug", sinks: ["file"] } ]});
With this configuration, all application logs at "info" level and above go to both console and file, while database-specific logs include more detailed "debug" level information, but only in the log file.
Structured Logging: Beyond Simple Text
Modern logging goes beyond simple text strings. LogTape embraces structured logging, which treats log entries as data objects rather than plain text:
The function is only evaluated if the debug level is enabled, preventing unnecessary computation for suppressed log levels.
Extremely Simple Sinks and Filters: Minimal Boilerplate
LogTape's approach to extensibility is remarkably straightforward. Creating custom sinks (output destinations) and filters requires minimal boilerplate code.
Dead Simple Sinks
A sink in LogTape is just a function that receives a log record:
// Creating a custom sink is as simple as defining a functionconst mySink = (record) => { const timestamp = new Date(record.timestamp).toISOString(); const level = record.level.toUpperCase(); const category = record.category.join('.'); // Send to your custom destination myCustomLogService.send({ time: timestamp, priority: level, component: category, message: record.message, ...record.properties });};// Use your custom sink in configurationawait configure({ sinks: { console: getConsoleSink(), custom: mySink }, loggers: [ { category: ["my-app"], sinks: ["console", "custom"] } ]});
Compare this with other libraries that require extending classes, implementing multiple methods, or following specific patterns. LogTape's approach is refreshingly straightforward.
Simple Filters
Similarly, filters in LogTape are just functions that return a Boolean:
// Filter that only passes high-priority or specific component logsconst importantLogsFilter = (record) => { // Always include errors if (record.level === "error" || record.level === "fatal") { return true; } // Always include payment-related logs if (record.category.includes("payments")) { return true; } // Filter out other logs return false;};await configure({ // ...sinks configuration filters: { important: importantLogsFilter }, loggers: [ { category: ["my-app"], sinks: ["alertSystem"], filters: ["important"] } ]});
LogTape also provides a convenient shorthand for level-based filtering:
await configure({ // ...sinks configuration filters: { // This creates a filter for "warning" level and above warningAndAbove: "warning" }, loggers: [ { category: ["my-app"], sinks: ["console"], filters: ["warningAndAbove"] } ]});
Perfect for Library Authors
LogTape is uniquely well-suited for library authors who want to incorporate logging without burdening their users. The core philosophy is simple:
The key point is that the library never calls configure(). Instead, it provides useful log output points with appropriate levels and contextual data.
Applications using the library can then decide exactly how to handle these logs:
// Application codeimport { configure, getConsoleSink } from "@logtape/logtape";import { Database } from "my-awesome-lib";// Configure how logs should be handledawait configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log") }, loggers: [ // Handle all library logs { category: ["my-awesome-lib"], lowestLevel: "info", sinks: ["file"] }, // More verbose for database component during development { category: ["my-awesome-lib", "database"], lowestLevel: "debug", sinks: ["console", "file"] } ]});// Use the libraryconst db = new Database("localhost", 5432, "user");db.connect();
This separation of concerns offers several benefits:
Library users have complete control over log handling
Libraries can provide rich logging without imposing implementation details
No risk of conflict with application logging configurations
Libraries can be "noisy" internally while allowing applications to filter as needed
Contexts for Richer Logging
LogTape provides context mechanisms for adding consistent properties across multiple log messages. This is particularly valuable for tracing requests through a system:
Explicit Contexts
const logger = getLogger(["my-app", "api"]);// Create a logger with contextconst requestLogger = logger.with({ requestId: "abc-123", userId: 42, endpoint: "/users"});// All logs from this logger include the context propertiesrequestLogger.info("Processing request");requestLogger.debug("Validating input");requestLogger.info("Request completed", { durationMs: 120 });
Implicit Contexts (v0.7.0+)
For cases where you want context to apply across function calls without explicit passing:
import { getLogger, withContext } from "@logtape/logtape";function handleRequest(req, res) { withContext({ requestId: req.id, userId: req.user?.id }, () => { // All logs within this function and any functions it calls // will automatically include the context properties processRequest(req, res); });}function processRequest(req, res) { // No need to pass context - it's automatically available getLogger(["my-app", "processor"]).info("Processing data"); // Call other functions that will also inherit the context validateInput(req.body);}function validateInput(data) { // This log also gets the requestId and userId getLogger(["my-app", "validator"]).debug("Validating input", { data });}
This implicit context capability is invaluable for tracing requests through multiple layers of code without manually threading context through every function call.
When LogTape Might Not Be Your Best Choice
While LogTape offers compelling advantages for many use cases, it's not universally the best choice:
Extreme performance requirements
If your application logs tens of thousands of entries per second and raw performance is the top priority, specialized high-performance libraries like Pino may be more suitable with their focus on optimized logging throughput.
Extensive pre-built integrations
If you need immediate integration with numerous specific systems (Elasticsearch, Graylog, etc.) without writing any custom code, Winston's rich ecosystem of transports might provide a faster starting point.
Legacy systems with specific logging requirements
If you're maintaining systems built around specific logging patterns from Java or other environments, purpose-built libraries like Log4js might offer more familiar APIs.
Web browser-only applications with minimal logging needs
For extremely simple web browser-only logging needs where you just want basic console output with levels, even simpler libraries like loglevel might be sufficient.
Conclusion
LogTape stands out in the crowded JavaScript logging landscape by offering a unique combination of features that address real-world development challenges:
Zero dependencies for a lightweight, secure foundation
Runtime diversity supporting Node.js, Deno, Bun, browsers, and edge functions
Hierarchical categories for better log organization and filtering
Structured logging for improved analysis and searchability
Simple extension mechanisms with minimal boilerplate
Library-friendly design that respects separation of concerns
Whether you're building applications or libraries, working across multiple JavaScript runtimes, or simply seeking a clean, well-designed logging solution, LogTape deserves serious consideration. Its thoughtful design balances simplicity with powerful features, avoiding common pitfalls of JavaScript logging libraries.
Building a JavaScript library is a delicate balance. You want to provide useful functionality while being respectful of your users' choices and constraints. When it comes to logging—something many libraries need for debugging, monitoring, and user support—this balance becomes particularly challenging.
The JavaScript ecosystem has evolved various approaches to this challenge, each with its own trade-offs. LogTape offers a different path, one that's specifically designed with library authors in mind.
The current state of library logging
If you've built libraries before, you've probably encountered the logging dilemma. Your library would benefit from logging—perhaps to help users debug integration issues, trace internal state changes, or provide insights into performance bottlenecks. But how do you add this capability responsibly?
Currently, popular libraries handle this challenge in several ways:
The debug approach
Libraries like Express and Socket.IO use the lightweight debug package, which allows users to enable logging through environment variables (DEBUG=express:*). This works well but creates a separate logging system that doesn't integrate with users' existing logging infrastructure.
Custom logging systems
Libraries like Mongoose and Prisma have built their own logging mechanisms. Mongoose offers mongoose.set('debug', true) while Prisma uses its own logging configuration. These approaches work, but each library creates its own logging API that users must learn separately.
Application-focused libraries
winston, Pino, and Bunyan are powerful logging solutions, but they're primarily designed for applications rather than libraries. Using them in a library means imposing significant dependencies and potentially conflicting with users' existing logging choices.
No logging at all
Many library authors avoid the complexity entirely, leaving their libraries silent and making debugging more challenging for everyone involved.
Dependency injection
Some libraries adopt a more sophisticated approach by accepting a logger instance from the application through their configuration or constructor parameters. This maintains clean separation of concerns and allows libraries to use whatever logging system the application has chosen. However, this pattern requires more complex APIs and places additional burden on library users to understand and configure logging dependencies.
Each approach represents a reasonable solution to a genuine problem, but none fully addresses the core tension: how do you provide valuable diagnostic capabilities without imposing choices on your users?
The fragmentation problem
There's another challenge that emerges when libraries each solve logging in their own way: fragmentation. Consider a typical Node.js application that might use Express for the web framework, Socket.IO for real-time communication, Axios for HTTP requests, Mongoose for database access, and several other specialized libraries.
Each library potentially has its own logging approach:
Authentication libraries often include their own logging mechanisms
From an application developer's perspective, this creates a management challenge. They must learn and configure multiple different logging systems, each with its own syntax, capabilities, and quirks. Logs are scattered across different outputs with inconsistent formats, making it difficult to get a unified view of what's happening in their application.
The lack of integration also means that powerful features like structured logging, log correlation, and centralized log management become much harder to implement consistently across all the libraries in use.
LogTape's approach
LogTape attempts to address these challenges with what might be called a “library-first design.” The core principle is simple but potentially powerful: if logging isn't configured, nothing happens. No output, no errors, no side effects—just complete transparency.
This approach allows you to add comprehensive logging to your library without any impact on users who don't want it. When a user imports your library and runs their code, LogTape's logging calls are essentially no-ops until someone explicitly configures logging. Users who want insights into your library's behavior can opt in; those who don't are completely unaffected.
More importantly, when users do choose to configure logging, all LogTape-enabled libraries can be managed through a single, unified configuration system. This means one consistent API, one log format, and one destination for all library logs while still allowing fine-grained control over what gets logged from which libraries.
Note
This approach isn't entirely novel—it draws inspiration from Python's standard logging library, which has successfully created a unified logging ecosystem. In Python, libraries like Requests, SQLAlchemy, and Django components all use the standard logging framework, allowing developers to configure all library logging through a single, consistent system. This has proven to be both practical and powerful, enabling rich diagnostic capabilities across the entire Python ecosystem while maintaining simplicity for application developers.
// In your library code - completely safe to includeimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-awesome-lib", "database"]);export function connectToDatabase(config) { logger.debug("Attempting database connection", { config }); // ... your logic logger.info("Database connection established");}
The dependency consideration
Modern JavaScript development involves careful consideration of dependencies. While popular logging libraries like winston and Pino are well-maintained and widely trusted, they do come with their own dependency trees. winston, for example, includes 17 dependencies, while Pino includes 1.
For library authors, this creates a consideration: every dependency you add becomes a dependency for your users, whether they want it or not. This isn't necessarily problematic (many excellent libraries have dependencies), but it does represent a choice you're making on behalf of your users.
LogTape takes a different approach with zero dependencies. This isn't just a philosophical choice—it has practical implications for your library's users. They won't see additional packages in their node_modules, won't need to worry about supply chain considerations for logging-related dependencies, and won't face potential version conflicts between your logging choice and theirs.
At just 5.3KB minified and gzipped, LogTape adds minimal weight to their bundles. The installation process becomes faster, the dependency tree stays cleaner, and security audits remain focused on the dependencies that directly serve your library's core functionality.
Breaking the compatibility chain
Here's a challenge that might be familiar: you want your library to support both ESM and CommonJS environments. Perhaps some of your users are working with legacy Node.js projects that rely on CommonJS, while others are using modern ESM setups or building for browsers.
The challenge becomes apparent when you have dependencies. While ESM modules can import CommonJS modules without issues, the reverse isn't true—CommonJS modules cannot require ESM-only packages (at least not until the experimental features in Node.js 22+ become stable). This creates an asymmetric compatibility constraint.
If your library depends on any ESM-only packages, your library effectively becomes ESM-only as well, since CommonJS environments won't be able to use it. This means that even one ESM-only dependency in your chain can prevent you from supporting CommonJS users.
LogTape supports both ESM and CommonJS completely, meaning it won't be the weak link that forces this limitation. Whether your users are working with legacy Node.js projects, cutting-edge ESM applications, or hybrid environments, LogTape adapts seamlessly to their setup.
More importantly, when LogTape provides native ESM support (rather than just being importable as CommonJS), it enables tree shaking in modern bundlers. Tree shaking allows bundlers to eliminate unused code during the build process, but it requires the static import/export structure that only ESM provides. While CommonJS modules can be imported into ESM projects, they're often treated as opaque blocks that can't be optimized, potentially including unused code in the final bundle.
For a logging library that aims to have minimal impact, this optimization capability can be meaningful, especially for applications where bundle size matters.
Universal runtime support
The JavaScript ecosystem spans an impressive range of runtime environments today. Your library might run in Node.js servers, Deno scripts, Bun applications, web browsers, or edge functions. LogTape works identically across all of these environments without requiring polyfills, compatibility layers, or runtime-specific code.
This universality means you can focus on your library's core functionality rather than worrying about whether your logging choice will work in every environment your users might encounter. Whether someone imports your library into a Cloudflare Worker, a Next.js application, or a Deno CLI tool, the logging behavior remains consistent and reliable.
Performance without compromise
One concern library authors often have about logging is performance impact. What if your users import your library into a high-performance application? What if they're running in a memory-constrained environment?
LogTape addresses this with remarkable efficiency when logging is disabled. The overhead of an unconfigured LogTape call is virtually zero—among the lowest of any logging solution available. This means you can add detailed logging throughout your library for development and debugging purposes without worrying about performance impact on users who don't enable it.
When logging is enabled, LogTape consistently outperforms other libraries, particularly for console output—often the most common logging destination during development.
Avoiding namespace collisions
Libraries sharing the same application can create logging chaos when they all output to the same namespace. LogTape's hierarchical category system elegantly solves this by encouraging libraries to use their own namespaces.
Your library might use categories like ["my-awesome-lib", "database"] or ["my-awesome-lib", "validation"], ensuring that your logs are clearly separated from other libraries and the main application. Users who configure LogTape can then control logging levels independently for different libraries and different components within those libraries.
Developer experience that just works
LogTape is built with TypeScript from the ground up, meaning your TypeScript-based library gets full type safety without additional dependencies or type packages. The API feels natural and modern, supporting both template literals and structured logging patterns that integrate well with contemporary JavaScript development practices.
// Template literal style - feels naturallogger.info`User ${userId} performed action ${action}`;// Structured logging - great for monitoringlogger.info("User action completed", { userId, action, duration });
Practical integration
Actually using LogTape in your library is refreshingly straightforward. You simply import the logger, create appropriately namespaced categories, and log where it makes sense. No configuration, no setup, no complex initialization sequences.
import { getLogger } from "@logtape/logtape";const logger = getLogger(["my-lib", "api"]);export async function fetchUserData(userId) { logger.debug("Fetching user data", { userId }); try { const response = await api.get(`/users/${userId}`); logger.info("User data retrieved successfully", { userId, status: response.status }); return response.data; } catch (error) { logger.error("Failed to fetch user data", { userId, error }); throw error; }}
For users who want to see these logs, configuration is equally simple:
If your potential users are already invested in other logging systems, LogTape provides adapters for popular libraries like winston and Pino. This allows LogTape-enabled libraries to integrate with existing logging infrastructure, routing their logs through whatever system applications are already using.
The existence of these adapters reveals an honest truth: LogTape isn't yet a widely-adopted standard in the JavaScript ecosystem. Most applications are still built around established logging libraries, and asking users to completely restructure their logging approach would be unrealistic. The adapters represent a practical compromise—they allow library authors to take advantage of LogTape's library-friendly design while respecting users' existing investments and preferences.
This approach reduces friction for adoption while still providing library authors with a modern, zero-dependency logging API. Perhaps over time, as more libraries adopt this pattern and more developers experience its benefits, the need for such adapters might diminish. But for now, they serve as a pragmatic bridge between LogTape's vision and the current reality of the ecosystem.
A choice worth considering
Ultimately, choosing LogTape for your library represents a particular philosophy about the relationship between libraries and applications. It's about providing capabilities while preserving choice, offering insights while avoiding imposition.
The traditional approaches—whether using debug packages, application-focused loggers, or custom solutions—each have their merits and have served the community well. LogTape simply offers another option: one designed specifically for the unique position libraries occupy in the JavaScript ecosystem.
For library authors, this approach might offer several practical benefits. Your library gets detailed logging for development, debugging, and user support, while your users retain complete autonomy over whether and how to use those capabilities.
The broader benefit might be a more cohesive logging experience across the JavaScript ecosystem—one where libraries can provide rich diagnostic information that integrates seamlessly with whatever logging strategy applications choose to employ.
In a world where every dependency decision has implications, LogTape offers an approach worth considering: a way to enhance your library's capabilities while respecting your users' preferences and existing choices.
Building a JavaScript library is a delicate balance. You want to provide useful functionality while being respectful of your users' choices and constraints. When it comes to logging—something many libraries need for debugging, monitoring, and user support—this balance becomes particularly challenging.
The JavaScript ecosystem has evolved various approaches to this challenge, each with its own trade-offs. LogTape offers a different path, one that's specifically designed with library authors in mind.
The current state of library logging
If you've built libraries before, you've probably encountered the logging dilemma. Your library would benefit from logging—perhaps to help users debug integration issues, trace internal state changes, or provide insights into performance bottlenecks. But how do you add this capability responsibly?
Currently, popular libraries handle this challenge in several ways:
The debug approach
Libraries like Express and Socket.IO use the lightweight debug package, which allows users to enable logging through environment variables (DEBUG=express:*). This works well but creates a separate logging system that doesn't integrate with users' existing logging infrastructure.
Custom logging systems
Libraries like Mongoose and Prisma have built their own logging mechanisms. Mongoose offers mongoose.set('debug', true) while Prisma uses its own logging configuration. These approaches work, but each library creates its own logging API that users must learn separately.
Application-focused libraries
winston, Pino, and Bunyan are powerful logging solutions, but they're primarily designed for applications rather than libraries. Using them in a library means imposing significant dependencies and potentially conflicting with users' existing logging choices.
No logging at all
Many library authors avoid the complexity entirely, leaving their libraries silent and making debugging more challenging for everyone involved.
Dependency injection
Some libraries adopt a more sophisticated approach by accepting a logger instance from the application through their configuration or constructor parameters. This maintains clean separation of concerns and allows libraries to use whatever logging system the application has chosen. However, this pattern requires more complex APIs and places additional burden on library users to understand and configure logging dependencies.
Each approach represents a reasonable solution to a genuine problem, but none fully addresses the core tension: how do you provide valuable diagnostic capabilities without imposing choices on your users?
The fragmentation problem
There's another challenge that emerges when libraries each solve logging in their own way: fragmentation. Consider a typical Node.js application that might use Express for the web framework, Socket.IO for real-time communication, Axios for HTTP requests, Mongoose for database access, and several other specialized libraries.
Each library potentially has its own logging approach:
Authentication libraries often include their own logging mechanisms
From an application developer's perspective, this creates a management challenge. They must learn and configure multiple different logging systems, each with its own syntax, capabilities, and quirks. Logs are scattered across different outputs with inconsistent formats, making it difficult to get a unified view of what's happening in their application.
The lack of integration also means that powerful features like structured logging, log correlation, and centralized log management become much harder to implement consistently across all the libraries in use.
LogTape's approach
LogTape attempts to address these challenges with what might be called a “library-first design.” The core principle is simple but potentially powerful: if logging isn't configured, nothing happens. No output, no errors, no side effects—just complete transparency.
This approach allows you to add comprehensive logging to your library without any impact on users who don't want it. When a user imports your library and runs their code, LogTape's logging calls are essentially no-ops until someone explicitly configures logging. Users who want insights into your library's behavior can opt in; those who don't are completely unaffected.
More importantly, when users do choose to configure logging, all LogTape-enabled libraries can be managed through a single, unified configuration system. This means one consistent API, one log format, and one destination for all library logs while still allowing fine-grained control over what gets logged from which libraries.
Note
This approach isn't entirely novel—it draws inspiration from Python's standard logging library, which has successfully created a unified logging ecosystem. In Python, libraries like Requests, SQLAlchemy, and Django components all use the standard logging framework, allowing developers to configure all library logging through a single, consistent system. This has proven to be both practical and powerful, enabling rich diagnostic capabilities across the entire Python ecosystem while maintaining simplicity for application developers.
// In your library code - completely safe to includeimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-awesome-lib", "database"]);export function connectToDatabase(config) { logger.debug("Attempting database connection", { config }); // ... your logic logger.info("Database connection established");}
The dependency consideration
Modern JavaScript development involves careful consideration of dependencies. While popular logging libraries like winston and Pino are well-maintained and widely trusted, they do come with their own dependency trees. winston, for example, includes 17 dependencies, while Pino includes 1.
For library authors, this creates a consideration: every dependency you add becomes a dependency for your users, whether they want it or not. This isn't necessarily problematic (many excellent libraries have dependencies), but it does represent a choice you're making on behalf of your users.
LogTape takes a different approach with zero dependencies. This isn't just a philosophical choice—it has practical implications for your library's users. They won't see additional packages in their node_modules, won't need to worry about supply chain considerations for logging-related dependencies, and won't face potential version conflicts between your logging choice and theirs.
At just 5.3KB minified and gzipped, LogTape adds minimal weight to their bundles. The installation process becomes faster, the dependency tree stays cleaner, and security audits remain focused on the dependencies that directly serve your library's core functionality.
Breaking the compatibility chain
Here's a challenge that might be familiar: you want your library to support both ESM and CommonJS environments. Perhaps some of your users are working with legacy Node.js projects that rely on CommonJS, while others are using modern ESM setups or building for browsers.
The challenge becomes apparent when you have dependencies. While ESM modules can import CommonJS modules without issues, the reverse isn't true—CommonJS modules cannot require ESM-only packages (at least not until the experimental features in Node.js 22+ become stable). This creates an asymmetric compatibility constraint.
If your library depends on any ESM-only packages, your library effectively becomes ESM-only as well, since CommonJS environments won't be able to use it. This means that even one ESM-only dependency in your chain can prevent you from supporting CommonJS users.
LogTape supports both ESM and CommonJS completely, meaning it won't be the weak link that forces this limitation. Whether your users are working with legacy Node.js projects, cutting-edge ESM applications, or hybrid environments, LogTape adapts seamlessly to their setup.
More importantly, when LogTape provides native ESM support (rather than just being importable as CommonJS), it enables tree shaking in modern bundlers. Tree shaking allows bundlers to eliminate unused code during the build process, but it requires the static import/export structure that only ESM provides. While CommonJS modules can be imported into ESM projects, they're often treated as opaque blocks that can't be optimized, potentially including unused code in the final bundle.
For a logging library that aims to have minimal impact, this optimization capability can be meaningful, especially for applications where bundle size matters.
Universal runtime support
The JavaScript ecosystem spans an impressive range of runtime environments today. Your library might run in Node.js servers, Deno scripts, Bun applications, web browsers, or edge functions. LogTape works identically across all of these environments without requiring polyfills, compatibility layers, or runtime-specific code.
This universality means you can focus on your library's core functionality rather than worrying about whether your logging choice will work in every environment your users might encounter. Whether someone imports your library into a Cloudflare Worker, a Next.js application, or a Deno CLI tool, the logging behavior remains consistent and reliable.
Performance without compromise
One concern library authors often have about logging is performance impact. What if your users import your library into a high-performance application? What if they're running in a memory-constrained environment?
LogTape addresses this with remarkable efficiency when logging is disabled. The overhead of an unconfigured LogTape call is virtually zero—among the lowest of any logging solution available. This means you can add detailed logging throughout your library for development and debugging purposes without worrying about performance impact on users who don't enable it.
When logging is enabled, LogTape consistently outperforms other libraries, particularly for console output—often the most common logging destination during development.
Avoiding namespace collisions
Libraries sharing the same application can create logging chaos when they all output to the same namespace. LogTape's hierarchical category system elegantly solves this by encouraging libraries to use their own namespaces.
Your library might use categories like ["my-awesome-lib", "database"] or ["my-awesome-lib", "validation"], ensuring that your logs are clearly separated from other libraries and the main application. Users who configure LogTape can then control logging levels independently for different libraries and different components within those libraries.
Developer experience that just works
LogTape is built with TypeScript from the ground up, meaning your TypeScript-based library gets full type safety without additional dependencies or type packages. The API feels natural and modern, supporting both template literals and structured logging patterns that integrate well with contemporary JavaScript development practices.
// Template literal style - feels naturallogger.info`User ${userId} performed action ${action}`;// Structured logging - great for monitoringlogger.info("User action completed", { userId, action, duration });
Practical integration
Actually using LogTape in your library is refreshingly straightforward. You simply import the logger, create appropriately namespaced categories, and log where it makes sense. No configuration, no setup, no complex initialization sequences.
import { getLogger } from "@logtape/logtape";const logger = getLogger(["my-lib", "api"]);export async function fetchUserData(userId) { logger.debug("Fetching user data", { userId }); try { const response = await api.get(`/users/${userId}`); logger.info("User data retrieved successfully", { userId, status: response.status }); return response.data; } catch (error) { logger.error("Failed to fetch user data", { userId, error }); throw error; }}
For users who want to see these logs, configuration is equally simple:
If your potential users are already invested in other logging systems, LogTape provides adapters for popular libraries like winston and Pino. This allows LogTape-enabled libraries to integrate with existing logging infrastructure, routing their logs through whatever system applications are already using.
The existence of these adapters reveals an honest truth: LogTape isn't yet a widely-adopted standard in the JavaScript ecosystem. Most applications are still built around established logging libraries, and asking users to completely restructure their logging approach would be unrealistic. The adapters represent a practical compromise—they allow library authors to take advantage of LogTape's library-friendly design while respecting users' existing investments and preferences.
This approach reduces friction for adoption while still providing library authors with a modern, zero-dependency logging API. Perhaps over time, as more libraries adopt this pattern and more developers experience its benefits, the need for such adapters might diminish. But for now, they serve as a pragmatic bridge between LogTape's vision and the current reality of the ecosystem.
A choice worth considering
Ultimately, choosing LogTape for your library represents a particular philosophy about the relationship between libraries and applications. It's about providing capabilities while preserving choice, offering insights while avoiding imposition.
The traditional approaches—whether using debug packages, application-focused loggers, or custom solutions—each have their merits and have served the community well. LogTape simply offers another option: one designed specifically for the unique position libraries occupy in the JavaScript ecosystem.
For library authors, this approach might offer several practical benefits. Your library gets detailed logging for development, debugging, and user support, while your users retain complete autonomy over whether and how to use those capabilities.
The broader benefit might be a more cohesive logging experience across the JavaScript ecosystem—one where libraries can provide rich diagnostic information that integrates seamlessly with whatever logging strategy applications choose to employ.
In a world where every dependency decision has implications, LogTape offers an approach worth considering: a way to enhance your library's capabilities while respecting your users' preferences and existing choices.
Just shared my thoughts on #JavaScript library #logging on Hacker News. Explores the fragmentation problem and dependency dilemmas from a library author's perspective. Would love to hear feedback from the #winston/#Pino users.
Building a JavaScript library is a delicate balance. You want to provide useful functionality while being respectful of your users' choices and constraints. When it comes to logging—something many libraries need for debugging, monitoring, and user support—this balance becomes particularly challenging.
The JavaScript ecosystem has evolved various approaches to this challenge, each with its own trade-offs. LogTape offers a different path, one that's specifically designed with library authors in mind.
The current state of library logging
If you've built libraries before, you've probably encountered the logging dilemma. Your library would benefit from logging—perhaps to help users debug integration issues, trace internal state changes, or provide insights into performance bottlenecks. But how do you add this capability responsibly?
Currently, popular libraries handle this challenge in several ways:
The debug approach
Libraries like Express and Socket.IO use the lightweight debug package, which allows users to enable logging through environment variables (DEBUG=express:*). This works well but creates a separate logging system that doesn't integrate with users' existing logging infrastructure.
Custom logging systems
Libraries like Mongoose and Prisma have built their own logging mechanisms. Mongoose offers mongoose.set('debug', true) while Prisma uses its own logging configuration. These approaches work, but each library creates its own logging API that users must learn separately.
Application-focused libraries
winston, Pino, and Bunyan are powerful logging solutions, but they're primarily designed for applications rather than libraries. Using them in a library means imposing significant dependencies and potentially conflicting with users' existing logging choices.
No logging at all
Many library authors avoid the complexity entirely, leaving their libraries silent and making debugging more challenging for everyone involved.
Dependency injection
Some libraries adopt a more sophisticated approach by accepting a logger instance from the application through their configuration or constructor parameters. This maintains clean separation of concerns and allows libraries to use whatever logging system the application has chosen. However, this pattern requires more complex APIs and places additional burden on library users to understand and configure logging dependencies.
Each approach represents a reasonable solution to a genuine problem, but none fully addresses the core tension: how do you provide valuable diagnostic capabilities without imposing choices on your users?
The fragmentation problem
There's another challenge that emerges when libraries each solve logging in their own way: fragmentation. Consider a typical Node.js application that might use Express for the web framework, Socket.IO for real-time communication, Axios for HTTP requests, Mongoose for database access, and several other specialized libraries.
Each library potentially has its own logging approach:
Authentication libraries often include their own logging mechanisms
From an application developer's perspective, this creates a management challenge. They must learn and configure multiple different logging systems, each with its own syntax, capabilities, and quirks. Logs are scattered across different outputs with inconsistent formats, making it difficult to get a unified view of what's happening in their application.
The lack of integration also means that powerful features like structured logging, log correlation, and centralized log management become much harder to implement consistently across all the libraries in use.
LogTape's approach
LogTape attempts to address these challenges with what might be called a “library-first design.” The core principle is simple but potentially powerful: if logging isn't configured, nothing happens. No output, no errors, no side effects—just complete transparency.
This approach allows you to add comprehensive logging to your library without any impact on users who don't want it. When a user imports your library and runs their code, LogTape's logging calls are essentially no-ops until someone explicitly configures logging. Users who want insights into your library's behavior can opt in; those who don't are completely unaffected.
More importantly, when users do choose to configure logging, all LogTape-enabled libraries can be managed through a single, unified configuration system. This means one consistent API, one log format, and one destination for all library logs while still allowing fine-grained control over what gets logged from which libraries.
Note
This approach isn't entirely novel—it draws inspiration from Python's standard logging library, which has successfully created a unified logging ecosystem. In Python, libraries like Requests, SQLAlchemy, and Django components all use the standard logging framework, allowing developers to configure all library logging through a single, consistent system. This has proven to be both practical and powerful, enabling rich diagnostic capabilities across the entire Python ecosystem while maintaining simplicity for application developers.
// In your library code - completely safe to includeimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-awesome-lib", "database"]);export function connectToDatabase(config) { logger.debug("Attempting database connection", { config }); // ... your logic logger.info("Database connection established");}
The dependency consideration
Modern JavaScript development involves careful consideration of dependencies. While popular logging libraries like winston and Pino are well-maintained and widely trusted, they do come with their own dependency trees. winston, for example, includes 17 dependencies, while Pino includes 1.
For library authors, this creates a consideration: every dependency you add becomes a dependency for your users, whether they want it or not. This isn't necessarily problematic (many excellent libraries have dependencies), but it does represent a choice you're making on behalf of your users.
LogTape takes a different approach with zero dependencies. This isn't just a philosophical choice—it has practical implications for your library's users. They won't see additional packages in their node_modules, won't need to worry about supply chain considerations for logging-related dependencies, and won't face potential version conflicts between your logging choice and theirs.
At just 5.3KB minified and gzipped, LogTape adds minimal weight to their bundles. The installation process becomes faster, the dependency tree stays cleaner, and security audits remain focused on the dependencies that directly serve your library's core functionality.
Breaking the compatibility chain
Here's a challenge that might be familiar: you want your library to support both ESM and CommonJS environments. Perhaps some of your users are working with legacy Node.js projects that rely on CommonJS, while others are using modern ESM setups or building for browsers.
The challenge becomes apparent when you have dependencies. While ESM modules can import CommonJS modules without issues, the reverse isn't true—CommonJS modules cannot require ESM-only packages (at least not until the experimental features in Node.js 22+ become stable). This creates an asymmetric compatibility constraint.
If your library depends on any ESM-only packages, your library effectively becomes ESM-only as well, since CommonJS environments won't be able to use it. This means that even one ESM-only dependency in your chain can prevent you from supporting CommonJS users.
LogTape supports both ESM and CommonJS completely, meaning it won't be the weak link that forces this limitation. Whether your users are working with legacy Node.js projects, cutting-edge ESM applications, or hybrid environments, LogTape adapts seamlessly to their setup.
More importantly, when LogTape provides native ESM support (rather than just being importable as CommonJS), it enables tree shaking in modern bundlers. Tree shaking allows bundlers to eliminate unused code during the build process, but it requires the static import/export structure that only ESM provides. While CommonJS modules can be imported into ESM projects, they're often treated as opaque blocks that can't be optimized, potentially including unused code in the final bundle.
For a logging library that aims to have minimal impact, this optimization capability can be meaningful, especially for applications where bundle size matters.
Universal runtime support
The JavaScript ecosystem spans an impressive range of runtime environments today. Your library might run in Node.js servers, Deno scripts, Bun applications, web browsers, or edge functions. LogTape works identically across all of these environments without requiring polyfills, compatibility layers, or runtime-specific code.
This universality means you can focus on your library's core functionality rather than worrying about whether your logging choice will work in every environment your users might encounter. Whether someone imports your library into a Cloudflare Worker, a Next.js application, or a Deno CLI tool, the logging behavior remains consistent and reliable.
Performance without compromise
One concern library authors often have about logging is performance impact. What if your users import your library into a high-performance application? What if they're running in a memory-constrained environment?
LogTape addresses this with remarkable efficiency when logging is disabled. The overhead of an unconfigured LogTape call is virtually zero—among the lowest of any logging solution available. This means you can add detailed logging throughout your library for development and debugging purposes without worrying about performance impact on users who don't enable it.
When logging is enabled, LogTape consistently outperforms other libraries, particularly for console output—often the most common logging destination during development.
Avoiding namespace collisions
Libraries sharing the same application can create logging chaos when they all output to the same namespace. LogTape's hierarchical category system elegantly solves this by encouraging libraries to use their own namespaces.
Your library might use categories like ["my-awesome-lib", "database"] or ["my-awesome-lib", "validation"], ensuring that your logs are clearly separated from other libraries and the main application. Users who configure LogTape can then control logging levels independently for different libraries and different components within those libraries.
Developer experience that just works
LogTape is built with TypeScript from the ground up, meaning your TypeScript-based library gets full type safety without additional dependencies or type packages. The API feels natural and modern, supporting both template literals and structured logging patterns that integrate well with contemporary JavaScript development practices.
// Template literal style - feels naturallogger.info`User ${userId} performed action ${action}`;// Structured logging - great for monitoringlogger.info("User action completed", { userId, action, duration });
Practical integration
Actually using LogTape in your library is refreshingly straightforward. You simply import the logger, create appropriately namespaced categories, and log where it makes sense. No configuration, no setup, no complex initialization sequences.
import { getLogger } from "@logtape/logtape";const logger = getLogger(["my-lib", "api"]);export async function fetchUserData(userId) { logger.debug("Fetching user data", { userId }); try { const response = await api.get(`/users/${userId}`); logger.info("User data retrieved successfully", { userId, status: response.status }); return response.data; } catch (error) { logger.error("Failed to fetch user data", { userId, error }); throw error; }}
For users who want to see these logs, configuration is equally simple:
If your potential users are already invested in other logging systems, LogTape provides adapters for popular libraries like winston and Pino. This allows LogTape-enabled libraries to integrate with existing logging infrastructure, routing their logs through whatever system applications are already using.
The existence of these adapters reveals an honest truth: LogTape isn't yet a widely-adopted standard in the JavaScript ecosystem. Most applications are still built around established logging libraries, and asking users to completely restructure their logging approach would be unrealistic. The adapters represent a practical compromise—they allow library authors to take advantage of LogTape's library-friendly design while respecting users' existing investments and preferences.
This approach reduces friction for adoption while still providing library authors with a modern, zero-dependency logging API. Perhaps over time, as more libraries adopt this pattern and more developers experience its benefits, the need for such adapters might diminish. But for now, they serve as a pragmatic bridge between LogTape's vision and the current reality of the ecosystem.
A choice worth considering
Ultimately, choosing LogTape for your library represents a particular philosophy about the relationship between libraries and applications. It's about providing capabilities while preserving choice, offering insights while avoiding imposition.
The traditional approaches—whether using debug packages, application-focused loggers, or custom solutions—each have their merits and have served the community well. LogTape simply offers another option: one designed specifically for the unique position libraries occupy in the JavaScript ecosystem.
For library authors, this approach might offer several practical benefits. Your library gets detailed logging for development, debugging, and user support, while your users retain complete autonomy over whether and how to use those capabilities.
The broader benefit might be a more cohesive logging experience across the JavaScript ecosystem—one where libraries can provide rich diagnostic information that integrates seamlessly with whatever logging strategy applications choose to employ.
In a world where every dependency decision has implications, LogTape offers an approach worth considering: a way to enhance your library's capabilities while respecting your users' preferences and existing choices.
Just shared my thoughts on #JavaScript library #logging on Hacker News. Explores the fragmentation problem and dependency dilemmas from a library author's perspective. Would love to hear feedback from the #winston/#Pino users.
Building a JavaScript library is a delicate balance. You want to provide useful functionality while being respectful of your users' choices and constraints. When it comes to logging—something many libraries need for debugging, monitoring, and user support—this balance becomes particularly challenging.
The JavaScript ecosystem has evolved various approaches to this challenge, each with its own trade-offs. LogTape offers a different path, one that's specifically designed with library authors in mind.
The current state of library logging
If you've built libraries before, you've probably encountered the logging dilemma. Your library would benefit from logging—perhaps to help users debug integration issues, trace internal state changes, or provide insights into performance bottlenecks. But how do you add this capability responsibly?
Currently, popular libraries handle this challenge in several ways:
The debug approach
Libraries like Express and Socket.IO use the lightweight debug package, which allows users to enable logging through environment variables (DEBUG=express:*). This works well but creates a separate logging system that doesn't integrate with users' existing logging infrastructure.
Custom logging systems
Libraries like Mongoose and Prisma have built their own logging mechanisms. Mongoose offers mongoose.set('debug', true) while Prisma uses its own logging configuration. These approaches work, but each library creates its own logging API that users must learn separately.
Application-focused libraries
winston, Pino, and Bunyan are powerful logging solutions, but they're primarily designed for applications rather than libraries. Using them in a library means imposing significant dependencies and potentially conflicting with users' existing logging choices.
No logging at all
Many library authors avoid the complexity entirely, leaving their libraries silent and making debugging more challenging for everyone involved.
Dependency injection
Some libraries adopt a more sophisticated approach by accepting a logger instance from the application through their configuration or constructor parameters. This maintains clean separation of concerns and allows libraries to use whatever logging system the application has chosen. However, this pattern requires more complex APIs and places additional burden on library users to understand and configure logging dependencies.
Each approach represents a reasonable solution to a genuine problem, but none fully addresses the core tension: how do you provide valuable diagnostic capabilities without imposing choices on your users?
The fragmentation problem
There's another challenge that emerges when libraries each solve logging in their own way: fragmentation. Consider a typical Node.js application that might use Express for the web framework, Socket.IO for real-time communication, Axios for HTTP requests, Mongoose for database access, and several other specialized libraries.
Each library potentially has its own logging approach:
Authentication libraries often include their own logging mechanisms
From an application developer's perspective, this creates a management challenge. They must learn and configure multiple different logging systems, each with its own syntax, capabilities, and quirks. Logs are scattered across different outputs with inconsistent formats, making it difficult to get a unified view of what's happening in their application.
The lack of integration also means that powerful features like structured logging, log correlation, and centralized log management become much harder to implement consistently across all the libraries in use.
LogTape's approach
LogTape attempts to address these challenges with what might be called a “library-first design.” The core principle is simple but potentially powerful: if logging isn't configured, nothing happens. No output, no errors, no side effects—just complete transparency.
This approach allows you to add comprehensive logging to your library without any impact on users who don't want it. When a user imports your library and runs their code, LogTape's logging calls are essentially no-ops until someone explicitly configures logging. Users who want insights into your library's behavior can opt in; those who don't are completely unaffected.
More importantly, when users do choose to configure logging, all LogTape-enabled libraries can be managed through a single, unified configuration system. This means one consistent API, one log format, and one destination for all library logs while still allowing fine-grained control over what gets logged from which libraries.
Note
This approach isn't entirely novel—it draws inspiration from Python's standard logging library, which has successfully created a unified logging ecosystem. In Python, libraries like Requests, SQLAlchemy, and Django components all use the standard logging framework, allowing developers to configure all library logging through a single, consistent system. This has proven to be both practical and powerful, enabling rich diagnostic capabilities across the entire Python ecosystem while maintaining simplicity for application developers.
// In your library code - completely safe to includeimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-awesome-lib", "database"]);export function connectToDatabase(config) { logger.debug("Attempting database connection", { config }); // ... your logic logger.info("Database connection established");}
The dependency consideration
Modern JavaScript development involves careful consideration of dependencies. While popular logging libraries like winston and Pino are well-maintained and widely trusted, they do come with their own dependency trees. winston, for example, includes 17 dependencies, while Pino includes 1.
For library authors, this creates a consideration: every dependency you add becomes a dependency for your users, whether they want it or not. This isn't necessarily problematic (many excellent libraries have dependencies), but it does represent a choice you're making on behalf of your users.
LogTape takes a different approach with zero dependencies. This isn't just a philosophical choice—it has practical implications for your library's users. They won't see additional packages in their node_modules, won't need to worry about supply chain considerations for logging-related dependencies, and won't face potential version conflicts between your logging choice and theirs.
At just 5.3KB minified and gzipped, LogTape adds minimal weight to their bundles. The installation process becomes faster, the dependency tree stays cleaner, and security audits remain focused on the dependencies that directly serve your library's core functionality.
Breaking the compatibility chain
Here's a challenge that might be familiar: you want your library to support both ESM and CommonJS environments. Perhaps some of your users are working with legacy Node.js projects that rely on CommonJS, while others are using modern ESM setups or building for browsers.
The challenge becomes apparent when you have dependencies. While ESM modules can import CommonJS modules without issues, the reverse isn't true—CommonJS modules cannot require ESM-only packages (at least not until the experimental features in Node.js 22+ become stable). This creates an asymmetric compatibility constraint.
If your library depends on any ESM-only packages, your library effectively becomes ESM-only as well, since CommonJS environments won't be able to use it. This means that even one ESM-only dependency in your chain can prevent you from supporting CommonJS users.
LogTape supports both ESM and CommonJS completely, meaning it won't be the weak link that forces this limitation. Whether your users are working with legacy Node.js projects, cutting-edge ESM applications, or hybrid environments, LogTape adapts seamlessly to their setup.
More importantly, when LogTape provides native ESM support (rather than just being importable as CommonJS), it enables tree shaking in modern bundlers. Tree shaking allows bundlers to eliminate unused code during the build process, but it requires the static import/export structure that only ESM provides. While CommonJS modules can be imported into ESM projects, they're often treated as opaque blocks that can't be optimized, potentially including unused code in the final bundle.
For a logging library that aims to have minimal impact, this optimization capability can be meaningful, especially for applications where bundle size matters.
Universal runtime support
The JavaScript ecosystem spans an impressive range of runtime environments today. Your library might run in Node.js servers, Deno scripts, Bun applications, web browsers, or edge functions. LogTape works identically across all of these environments without requiring polyfills, compatibility layers, or runtime-specific code.
This universality means you can focus on your library's core functionality rather than worrying about whether your logging choice will work in every environment your users might encounter. Whether someone imports your library into a Cloudflare Worker, a Next.js application, or a Deno CLI tool, the logging behavior remains consistent and reliable.
Performance without compromise
One concern library authors often have about logging is performance impact. What if your users import your library into a high-performance application? What if they're running in a memory-constrained environment?
LogTape addresses this with remarkable efficiency when logging is disabled. The overhead of an unconfigured LogTape call is virtually zero—among the lowest of any logging solution available. This means you can add detailed logging throughout your library for development and debugging purposes without worrying about performance impact on users who don't enable it.
When logging is enabled, LogTape consistently outperforms other libraries, particularly for console output—often the most common logging destination during development.
Avoiding namespace collisions
Libraries sharing the same application can create logging chaos when they all output to the same namespace. LogTape's hierarchical category system elegantly solves this by encouraging libraries to use their own namespaces.
Your library might use categories like ["my-awesome-lib", "database"] or ["my-awesome-lib", "validation"], ensuring that your logs are clearly separated from other libraries and the main application. Users who configure LogTape can then control logging levels independently for different libraries and different components within those libraries.
Developer experience that just works
LogTape is built with TypeScript from the ground up, meaning your TypeScript-based library gets full type safety without additional dependencies or type packages. The API feels natural and modern, supporting both template literals and structured logging patterns that integrate well with contemporary JavaScript development practices.
// Template literal style - feels naturallogger.info`User ${userId} performed action ${action}`;// Structured logging - great for monitoringlogger.info("User action completed", { userId, action, duration });
Practical integration
Actually using LogTape in your library is refreshingly straightforward. You simply import the logger, create appropriately namespaced categories, and log where it makes sense. No configuration, no setup, no complex initialization sequences.
import { getLogger } from "@logtape/logtape";const logger = getLogger(["my-lib", "api"]);export async function fetchUserData(userId) { logger.debug("Fetching user data", { userId }); try { const response = await api.get(`/users/${userId}`); logger.info("User data retrieved successfully", { userId, status: response.status }); return response.data; } catch (error) { logger.error("Failed to fetch user data", { userId, error }); throw error; }}
For users who want to see these logs, configuration is equally simple:
If your potential users are already invested in other logging systems, LogTape provides adapters for popular libraries like winston and Pino. This allows LogTape-enabled libraries to integrate with existing logging infrastructure, routing their logs through whatever system applications are already using.
The existence of these adapters reveals an honest truth: LogTape isn't yet a widely-adopted standard in the JavaScript ecosystem. Most applications are still built around established logging libraries, and asking users to completely restructure their logging approach would be unrealistic. The adapters represent a practical compromise—they allow library authors to take advantage of LogTape's library-friendly design while respecting users' existing investments and preferences.
This approach reduces friction for adoption while still providing library authors with a modern, zero-dependency logging API. Perhaps over time, as more libraries adopt this pattern and more developers experience its benefits, the need for such adapters might diminish. But for now, they serve as a pragmatic bridge between LogTape's vision and the current reality of the ecosystem.
A choice worth considering
Ultimately, choosing LogTape for your library represents a particular philosophy about the relationship between libraries and applications. It's about providing capabilities while preserving choice, offering insights while avoiding imposition.
The traditional approaches—whether using debug packages, application-focused loggers, or custom solutions—each have their merits and have served the community well. LogTape simply offers another option: one designed specifically for the unique position libraries occupy in the JavaScript ecosystem.
For library authors, this approach might offer several practical benefits. Your library gets detailed logging for development, debugging, and user support, while your users retain complete autonomy over whether and how to use those capabilities.
The broader benefit might be a more cohesive logging experience across the JavaScript ecosystem—one where libraries can provide rich diagnostic information that integrates seamlessly with whatever logging strategy applications choose to employ.
In a world where every dependency decision has implications, LogTape offers an approach worth considering: a way to enhance your library's capabilities while respecting your users' preferences and existing choices.
Building a JavaScript library is a delicate balance. You want to provide useful functionality while being respectful of your users' choices and constraints. When it comes to logging—something many libraries need for debugging, monitoring, and user support—this balance becomes particularly challenging.
The JavaScript ecosystem has evolved various approaches to this challenge, each with its own trade-offs. LogTape offers a different path, one that's specifically designed with library authors in mind.
The current state of library logging
If you've built libraries before, you've probably encountered the logging dilemma. Your library would benefit from logging—perhaps to help users debug integration issues, trace internal state changes, or provide insights into performance bottlenecks. But how do you add this capability responsibly?
Currently, popular libraries handle this challenge in several ways:
The debug approach
Libraries like Express and Socket.IO use the lightweight debug package, which allows users to enable logging through environment variables (DEBUG=express:*). This works well but creates a separate logging system that doesn't integrate with users' existing logging infrastructure.
Custom logging systems
Libraries like Mongoose and Prisma have built their own logging mechanisms. Mongoose offers mongoose.set('debug', true) while Prisma uses its own logging configuration. These approaches work, but each library creates its own logging API that users must learn separately.
Application-focused libraries
winston, Pino, and Bunyan are powerful logging solutions, but they're primarily designed for applications rather than libraries. Using them in a library means imposing significant dependencies and potentially conflicting with users' existing logging choices.
No logging at all
Many library authors avoid the complexity entirely, leaving their libraries silent and making debugging more challenging for everyone involved.
Dependency injection
Some libraries adopt a more sophisticated approach by accepting a logger instance from the application through their configuration or constructor parameters. This maintains clean separation of concerns and allows libraries to use whatever logging system the application has chosen. However, this pattern requires more complex APIs and places additional burden on library users to understand and configure logging dependencies.
Each approach represents a reasonable solution to a genuine problem, but none fully addresses the core tension: how do you provide valuable diagnostic capabilities without imposing choices on your users?
The fragmentation problem
There's another challenge that emerges when libraries each solve logging in their own way: fragmentation. Consider a typical Node.js application that might use Express for the web framework, Socket.IO for real-time communication, Axios for HTTP requests, Mongoose for database access, and several other specialized libraries.
Each library potentially has its own logging approach:
Authentication libraries often include their own logging mechanisms
From an application developer's perspective, this creates a management challenge. They must learn and configure multiple different logging systems, each with its own syntax, capabilities, and quirks. Logs are scattered across different outputs with inconsistent formats, making it difficult to get a unified view of what's happening in their application.
The lack of integration also means that powerful features like structured logging, log correlation, and centralized log management become much harder to implement consistently across all the libraries in use.
LogTape's approach
LogTape attempts to address these challenges with what might be called a “library-first design.” The core principle is simple but potentially powerful: if logging isn't configured, nothing happens. No output, no errors, no side effects—just complete transparency.
This approach allows you to add comprehensive logging to your library without any impact on users who don't want it. When a user imports your library and runs their code, LogTape's logging calls are essentially no-ops until someone explicitly configures logging. Users who want insights into your library's behavior can opt in; those who don't are completely unaffected.
More importantly, when users do choose to configure logging, all LogTape-enabled libraries can be managed through a single, unified configuration system. This means one consistent API, one log format, and one destination for all library logs while still allowing fine-grained control over what gets logged from which libraries.
Note
This approach isn't entirely novel—it draws inspiration from Python's standard logging library, which has successfully created a unified logging ecosystem. In Python, libraries like Requests, SQLAlchemy, and Django components all use the standard logging framework, allowing developers to configure all library logging through a single, consistent system. This has proven to be both practical and powerful, enabling rich diagnostic capabilities across the entire Python ecosystem while maintaining simplicity for application developers.
// In your library code - completely safe to includeimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-awesome-lib", "database"]);export function connectToDatabase(config) { logger.debug("Attempting database connection", { config }); // ... your logic logger.info("Database connection established");}
The dependency consideration
Modern JavaScript development involves careful consideration of dependencies. While popular logging libraries like winston and Pino are well-maintained and widely trusted, they do come with their own dependency trees. winston, for example, includes 17 dependencies, while Pino includes 1.
For library authors, this creates a consideration: every dependency you add becomes a dependency for your users, whether they want it or not. This isn't necessarily problematic (many excellent libraries have dependencies), but it does represent a choice you're making on behalf of your users.
LogTape takes a different approach with zero dependencies. This isn't just a philosophical choice—it has practical implications for your library's users. They won't see additional packages in their node_modules, won't need to worry about supply chain considerations for logging-related dependencies, and won't face potential version conflicts between your logging choice and theirs.
At just 5.3KB minified and gzipped, LogTape adds minimal weight to their bundles. The installation process becomes faster, the dependency tree stays cleaner, and security audits remain focused on the dependencies that directly serve your library's core functionality.
Breaking the compatibility chain
Here's a challenge that might be familiar: you want your library to support both ESM and CommonJS environments. Perhaps some of your users are working with legacy Node.js projects that rely on CommonJS, while others are using modern ESM setups or building for browsers.
The challenge becomes apparent when you have dependencies. While ESM modules can import CommonJS modules without issues, the reverse isn't true—CommonJS modules cannot require ESM-only packages (at least not until the experimental features in Node.js 22+ become stable). This creates an asymmetric compatibility constraint.
If your library depends on any ESM-only packages, your library effectively becomes ESM-only as well, since CommonJS environments won't be able to use it. This means that even one ESM-only dependency in your chain can prevent you from supporting CommonJS users.
LogTape supports both ESM and CommonJS completely, meaning it won't be the weak link that forces this limitation. Whether your users are working with legacy Node.js projects, cutting-edge ESM applications, or hybrid environments, LogTape adapts seamlessly to their setup.
More importantly, when LogTape provides native ESM support (rather than just being importable as CommonJS), it enables tree shaking in modern bundlers. Tree shaking allows bundlers to eliminate unused code during the build process, but it requires the static import/export structure that only ESM provides. While CommonJS modules can be imported into ESM projects, they're often treated as opaque blocks that can't be optimized, potentially including unused code in the final bundle.
For a logging library that aims to have minimal impact, this optimization capability can be meaningful, especially for applications where bundle size matters.
Universal runtime support
The JavaScript ecosystem spans an impressive range of runtime environments today. Your library might run in Node.js servers, Deno scripts, Bun applications, web browsers, or edge functions. LogTape works identically across all of these environments without requiring polyfills, compatibility layers, or runtime-specific code.
This universality means you can focus on your library's core functionality rather than worrying about whether your logging choice will work in every environment your users might encounter. Whether someone imports your library into a Cloudflare Worker, a Next.js application, or a Deno CLI tool, the logging behavior remains consistent and reliable.
Performance without compromise
One concern library authors often have about logging is performance impact. What if your users import your library into a high-performance application? What if they're running in a memory-constrained environment?
LogTape addresses this with remarkable efficiency when logging is disabled. The overhead of an unconfigured LogTape call is virtually zero—among the lowest of any logging solution available. This means you can add detailed logging throughout your library for development and debugging purposes without worrying about performance impact on users who don't enable it.
When logging is enabled, LogTape consistently outperforms other libraries, particularly for console output—often the most common logging destination during development.
Avoiding namespace collisions
Libraries sharing the same application can create logging chaos when they all output to the same namespace. LogTape's hierarchical category system elegantly solves this by encouraging libraries to use their own namespaces.
Your library might use categories like ["my-awesome-lib", "database"] or ["my-awesome-lib", "validation"], ensuring that your logs are clearly separated from other libraries and the main application. Users who configure LogTape can then control logging levels independently for different libraries and different components within those libraries.
Developer experience that just works
LogTape is built with TypeScript from the ground up, meaning your TypeScript-based library gets full type safety without additional dependencies or type packages. The API feels natural and modern, supporting both template literals and structured logging patterns that integrate well with contemporary JavaScript development practices.
// Template literal style - feels naturallogger.info`User ${userId} performed action ${action}`;// Structured logging - great for monitoringlogger.info("User action completed", { userId, action, duration });
Practical integration
Actually using LogTape in your library is refreshingly straightforward. You simply import the logger, create appropriately namespaced categories, and log where it makes sense. No configuration, no setup, no complex initialization sequences.
import { getLogger } from "@logtape/logtape";const logger = getLogger(["my-lib", "api"]);export async function fetchUserData(userId) { logger.debug("Fetching user data", { userId }); try { const response = await api.get(`/users/${userId}`); logger.info("User data retrieved successfully", { userId, status: response.status }); return response.data; } catch (error) { logger.error("Failed to fetch user data", { userId, error }); throw error; }}
For users who want to see these logs, configuration is equally simple:
If your potential users are already invested in other logging systems, LogTape provides adapters for popular libraries like winston and Pino. This allows LogTape-enabled libraries to integrate with existing logging infrastructure, routing their logs through whatever system applications are already using.
The existence of these adapters reveals an honest truth: LogTape isn't yet a widely-adopted standard in the JavaScript ecosystem. Most applications are still built around established logging libraries, and asking users to completely restructure their logging approach would be unrealistic. The adapters represent a practical compromise—they allow library authors to take advantage of LogTape's library-friendly design while respecting users' existing investments and preferences.
This approach reduces friction for adoption while still providing library authors with a modern, zero-dependency logging API. Perhaps over time, as more libraries adopt this pattern and more developers experience its benefits, the need for such adapters might diminish. But for now, they serve as a pragmatic bridge between LogTape's vision and the current reality of the ecosystem.
A choice worth considering
Ultimately, choosing LogTape for your library represents a particular philosophy about the relationship between libraries and applications. It's about providing capabilities while preserving choice, offering insights while avoiding imposition.
The traditional approaches—whether using debug packages, application-focused loggers, or custom solutions—each have their merits and have served the community well. LogTape simply offers another option: one designed specifically for the unique position libraries occupy in the JavaScript ecosystem.
For library authors, this approach might offer several practical benefits. Your library gets detailed logging for development, debugging, and user support, while your users retain complete autonomy over whether and how to use those capabilities.
The broader benefit might be a more cohesive logging experience across the JavaScript ecosystem—one where libraries can provide rich diagnostic information that integrates seamlessly with whatever logging strategy applications choose to employ.
In a world where every dependency decision has implications, LogTape offers an approach worth considering: a way to enhance your library's capabilities while respecting your users' preferences and existing choices.
Building a JavaScript library is a delicate balance. You want to provide useful functionality while being respectful of your users' choices and constraints. When it comes to logging—something many libraries need for debugging, monitoring, and user support—this balance becomes particularly challenging.
The JavaScript ecosystem has evolved various approaches to this challenge, each with its own trade-offs. LogTape offers a different path, one that's specifically designed with library authors in mind.
The current state of library logging
If you've built libraries before, you've probably encountered the logging dilemma. Your library would benefit from logging—perhaps to help users debug integration issues, trace internal state changes, or provide insights into performance bottlenecks. But how do you add this capability responsibly?
Currently, popular libraries handle this challenge in several ways:
The debug approach
Libraries like Express and Socket.IO use the lightweight debug package, which allows users to enable logging through environment variables (DEBUG=express:*). This works well but creates a separate logging system that doesn't integrate with users' existing logging infrastructure.
Custom logging systems
Libraries like Mongoose and Prisma have built their own logging mechanisms. Mongoose offers mongoose.set('debug', true) while Prisma uses its own logging configuration. These approaches work, but each library creates its own logging API that users must learn separately.
Application-focused libraries
winston, Pino, and Bunyan are powerful logging solutions, but they're primarily designed for applications rather than libraries. Using them in a library means imposing significant dependencies and potentially conflicting with users' existing logging choices.
No logging at all
Many library authors avoid the complexity entirely, leaving their libraries silent and making debugging more challenging for everyone involved.
Dependency injection
Some libraries adopt a more sophisticated approach by accepting a logger instance from the application through their configuration or constructor parameters. This maintains clean separation of concerns and allows libraries to use whatever logging system the application has chosen. However, this pattern requires more complex APIs and places additional burden on library users to understand and configure logging dependencies.
Each approach represents a reasonable solution to a genuine problem, but none fully addresses the core tension: how do you provide valuable diagnostic capabilities without imposing choices on your users?
The fragmentation problem
There's another challenge that emerges when libraries each solve logging in their own way: fragmentation. Consider a typical Node.js application that might use Express for the web framework, Socket.IO for real-time communication, Axios for HTTP requests, Mongoose for database access, and several other specialized libraries.
Each library potentially has its own logging approach:
Authentication libraries often include their own logging mechanisms
From an application developer's perspective, this creates a management challenge. They must learn and configure multiple different logging systems, each with its own syntax, capabilities, and quirks. Logs are scattered across different outputs with inconsistent formats, making it difficult to get a unified view of what's happening in their application.
The lack of integration also means that powerful features like structured logging, log correlation, and centralized log management become much harder to implement consistently across all the libraries in use.
LogTape's approach
LogTape attempts to address these challenges with what might be called a “library-first design.” The core principle is simple but potentially powerful: if logging isn't configured, nothing happens. No output, no errors, no side effects—just complete transparency.
This approach allows you to add comprehensive logging to your library without any impact on users who don't want it. When a user imports your library and runs their code, LogTape's logging calls are essentially no-ops until someone explicitly configures logging. Users who want insights into your library's behavior can opt in; those who don't are completely unaffected.
More importantly, when users do choose to configure logging, all LogTape-enabled libraries can be managed through a single, unified configuration system. This means one consistent API, one log format, and one destination for all library logs while still allowing fine-grained control over what gets logged from which libraries.
Note
This approach isn't entirely novel—it draws inspiration from Python's standard logging library, which has successfully created a unified logging ecosystem. In Python, libraries like Requests, SQLAlchemy, and Django components all use the standard logging framework, allowing developers to configure all library logging through a single, consistent system. This has proven to be both practical and powerful, enabling rich diagnostic capabilities across the entire Python ecosystem while maintaining simplicity for application developers.
// In your library code - completely safe to includeimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-awesome-lib", "database"]);export function connectToDatabase(config) { logger.debug("Attempting database connection", { config }); // ... your logic logger.info("Database connection established");}
The dependency consideration
Modern JavaScript development involves careful consideration of dependencies. While popular logging libraries like winston and Pino are well-maintained and widely trusted, they do come with their own dependency trees. winston, for example, includes 17 dependencies, while Pino includes 1.
For library authors, this creates a consideration: every dependency you add becomes a dependency for your users, whether they want it or not. This isn't necessarily problematic (many excellent libraries have dependencies), but it does represent a choice you're making on behalf of your users.
LogTape takes a different approach with zero dependencies. This isn't just a philosophical choice—it has practical implications for your library's users. They won't see additional packages in their node_modules, won't need to worry about supply chain considerations for logging-related dependencies, and won't face potential version conflicts between your logging choice and theirs.
At just 5.3KB minified and gzipped, LogTape adds minimal weight to their bundles. The installation process becomes faster, the dependency tree stays cleaner, and security audits remain focused on the dependencies that directly serve your library's core functionality.
Breaking the compatibility chain
Here's a challenge that might be familiar: you want your library to support both ESM and CommonJS environments. Perhaps some of your users are working with legacy Node.js projects that rely on CommonJS, while others are using modern ESM setups or building for browsers.
The challenge becomes apparent when you have dependencies. While ESM modules can import CommonJS modules without issues, the reverse isn't true—CommonJS modules cannot require ESM-only packages (at least not until the experimental features in Node.js 22+ become stable). This creates an asymmetric compatibility constraint.
If your library depends on any ESM-only packages, your library effectively becomes ESM-only as well, since CommonJS environments won't be able to use it. This means that even one ESM-only dependency in your chain can prevent you from supporting CommonJS users.
LogTape supports both ESM and CommonJS completely, meaning it won't be the weak link that forces this limitation. Whether your users are working with legacy Node.js projects, cutting-edge ESM applications, or hybrid environments, LogTape adapts seamlessly to their setup.
More importantly, when LogTape provides native ESM support (rather than just being importable as CommonJS), it enables tree shaking in modern bundlers. Tree shaking allows bundlers to eliminate unused code during the build process, but it requires the static import/export structure that only ESM provides. While CommonJS modules can be imported into ESM projects, they're often treated as opaque blocks that can't be optimized, potentially including unused code in the final bundle.
For a logging library that aims to have minimal impact, this optimization capability can be meaningful, especially for applications where bundle size matters.
Universal runtime support
The JavaScript ecosystem spans an impressive range of runtime environments today. Your library might run in Node.js servers, Deno scripts, Bun applications, web browsers, or edge functions. LogTape works identically across all of these environments without requiring polyfills, compatibility layers, or runtime-specific code.
This universality means you can focus on your library's core functionality rather than worrying about whether your logging choice will work in every environment your users might encounter. Whether someone imports your library into a Cloudflare Worker, a Next.js application, or a Deno CLI tool, the logging behavior remains consistent and reliable.
Performance without compromise
One concern library authors often have about logging is performance impact. What if your users import your library into a high-performance application? What if they're running in a memory-constrained environment?
LogTape addresses this with remarkable efficiency when logging is disabled. The overhead of an unconfigured LogTape call is virtually zero—among the lowest of any logging solution available. This means you can add detailed logging throughout your library for development and debugging purposes without worrying about performance impact on users who don't enable it.
When logging is enabled, LogTape consistently outperforms other libraries, particularly for console output—often the most common logging destination during development.
Avoiding namespace collisions
Libraries sharing the same application can create logging chaos when they all output to the same namespace. LogTape's hierarchical category system elegantly solves this by encouraging libraries to use their own namespaces.
Your library might use categories like ["my-awesome-lib", "database"] or ["my-awesome-lib", "validation"], ensuring that your logs are clearly separated from other libraries and the main application. Users who configure LogTape can then control logging levels independently for different libraries and different components within those libraries.
Developer experience that just works
LogTape is built with TypeScript from the ground up, meaning your TypeScript-based library gets full type safety without additional dependencies or type packages. The API feels natural and modern, supporting both template literals and structured logging patterns that integrate well with contemporary JavaScript development practices.
// Template literal style - feels naturallogger.info`User ${userId} performed action ${action}`;// Structured logging - great for monitoringlogger.info("User action completed", { userId, action, duration });
Practical integration
Actually using LogTape in your library is refreshingly straightforward. You simply import the logger, create appropriately namespaced categories, and log where it makes sense. No configuration, no setup, no complex initialization sequences.
import { getLogger } from "@logtape/logtape";const logger = getLogger(["my-lib", "api"]);export async function fetchUserData(userId) { logger.debug("Fetching user data", { userId }); try { const response = await api.get(`/users/${userId}`); logger.info("User data retrieved successfully", { userId, status: response.status }); return response.data; } catch (error) { logger.error("Failed to fetch user data", { userId, error }); throw error; }}
For users who want to see these logs, configuration is equally simple:
If your potential users are already invested in other logging systems, LogTape provides adapters for popular libraries like winston and Pino. This allows LogTape-enabled libraries to integrate with existing logging infrastructure, routing their logs through whatever system applications are already using.
The existence of these adapters reveals an honest truth: LogTape isn't yet a widely-adopted standard in the JavaScript ecosystem. Most applications are still built around established logging libraries, and asking users to completely restructure their logging approach would be unrealistic. The adapters represent a practical compromise—they allow library authors to take advantage of LogTape's library-friendly design while respecting users' existing investments and preferences.
This approach reduces friction for adoption while still providing library authors with a modern, zero-dependency logging API. Perhaps over time, as more libraries adopt this pattern and more developers experience its benefits, the need for such adapters might diminish. But for now, they serve as a pragmatic bridge between LogTape's vision and the current reality of the ecosystem.
A choice worth considering
Ultimately, choosing LogTape for your library represents a particular philosophy about the relationship between libraries and applications. It's about providing capabilities while preserving choice, offering insights while avoiding imposition.
The traditional approaches—whether using debug packages, application-focused loggers, or custom solutions—each have their merits and have served the community well. LogTape simply offers another option: one designed specifically for the unique position libraries occupy in the JavaScript ecosystem.
For library authors, this approach might offer several practical benefits. Your library gets detailed logging for development, debugging, and user support, while your users retain complete autonomy over whether and how to use those capabilities.
The broader benefit might be a more cohesive logging experience across the JavaScript ecosystem—one where libraries can provide rich diagnostic information that integrates seamlessly with whatever logging strategy applications choose to employ.
In a world where every dependency decision has implications, LogTape offers an approach worth considering: a way to enhance your library's capabilities while respecting your users' preferences and existing choices.
LogTape is a logging library designed specifically for the modern JavaScript ecosystem. It stands out with its zero-dependency architecture, universal runtime support across Node.js, Deno, Bun, browsers, and edge functions, and a library-first design philosophy that allows library authors to add logging without imposing any burden on their users. When LogTape isn't configured, logging calls have virtually no performance impact, making it the only truly unobtrusive logging solution available.
For a comprehensive overview of LogTape's capabilities and philosophy, see our introduction guide.
Milestone achievement
We're excited to announce LogTape 1.0.0, marking a significant milestone in the library's development. This release represents our commitment to API stability and long-term support. The 1.0.0 designation signals that LogTape's core APIs are now stable and ready for production use, with any future breaking changes following semantic versioning principles.
This milestone builds upon months of refinement, community feedback, and real-world usage, establishing LogTape as a mature and reliable logging solution for JavaScript applications and libraries.
Major new features
High-performance logging infrastructure
LogTape 1.0.0 introduces several performance-oriented features designed for high-throughput production environments. The new non-blocking sink option allows console, stream, and file sinks to buffer log records and flush them asynchronously, preventing logging operations from blocking your application's main thread.
The new fromAsyncSink() function provides a clean way to integrate asynchronous logging operations while maintaining LogTape's synchronous sink interface. This enables scenarios like sending logs to remote servers or databases without blocking your application.
For file operations specifically, the new getStreamFileSink() function in the @logtape/file package leverages Node.js PassThrough streams to deliver optimal I/O performance with automatic backpressure management.
New sink integrations
This release significantly expands LogTape's integration capabilities with two major new sink packages. The @logtape/cloudwatch-logs package enables direct integration with AWS CloudWatch Logs, featuring intelligent batching, exponential backoff retry strategies, and support for structured logging through JSON Lines formatting.
The @logtape/windows-eventlog package brings native Windows Event Log support with cross-runtime compatibility across Deno, Node.js, and Bun. This integration uses runtime-optimized FFI implementations for maximum performance while maintaining proper error handling and resource cleanup.
Beautiful development experience
The new @logtape/pretty package transforms console logging into a visually appealing experience designed specifically for local development. Inspired by Signale, it features colorful emojis for each log level, smart category truncation that preserves important context, and perfect column alignment that makes logs easy to scan.
As shown above, the pretty formatter supports true color terminals with rich color schemes, configurable icons, and intelligent word wrapping that maintains visual consistency even for long messages.
Ecosystem integration
Perhaps most significantly, LogTape 1.0.0 introduces adapter packages that bridge the gap between LogTape's library-friendly design and existing logging infrastructure. The @logtape/adaptor-winston and @logtape/adaptor-pino packages allow applications using these established logging libraries to seamlessly integrate LogTape-enabled libraries without changing their existing setup.
// Quick setup with winstonimport "@logtape/adaptor-winston/install";
// Or with custom configurationimport { install } from "@logtape/adaptor-winston";import winston from "winston";const logger = winston.createLogger({/* your config */});install(logger);
These adapters preserve LogTape's structured logging capabilities while routing everything through your preferred logging system, making adoption of LogTape-enabled libraries frictionless for existing applications.
Developer experience enhancements
This release includes several quality-of-life improvements for developers working with LogTape. The new getLogLevels() function provides programmatic access to all available log levels, while the LogMethod type offers better type inference for logging methods.
Browser compatibility has been improved, particularly for the @logtape/otel package, which previously had issues in browser environments due to Node.js-specific imports. The package now works seamlessly across all JavaScript runtimes without throwing module resolution errors.
Breaking changes and migration guide
LogTape 1.0.0 includes one notable breaking change: the removal of the deprecated LoggerConfig.level property. This property was deprecated in version 0.8.0 in favor of the more descriptive LoggerConfig.lowestLevel property.
If your configuration still uses the old property, simply rename it:
// Before (deprecated){ category: ["app"], level: "info", sinks: ["console"] }
For more complex filtering requirements, consider using the LoggerConfig.filters option instead, which provides more flexibility and supports inheritance from parent loggers.
Complete package ecosystem
LogTape 1.0.0 represents the culmination of a comprehensive package ecosystem, now consisting of 11 specialized packages that address different aspects of logging infrastructure. This modular approach allows you to install only the packages you need, keeping your dependency footprint minimal while accessing powerful logging capabilities when required.
Whether you're new to LogTape or upgrading from a previous version, getting started with 1.0.0 is straightforward. For new projects, begin with a simple configuration and gradually add the packages and features you need:
Existing applications using winston or Pino can immediately benefit from LogTape-enabled libraries by installing the appropriate adapter. For comprehensive migration guidance and detailed feature documentation, visit our documentation site.
The 1.0.0 release represents not just a version number, but a commitment to the stability and maturity that production applications require. We're excited to see what you'll build with LogTape.
LogTape is a logging library designed specifically for the modern JavaScript ecosystem. It stands out with its zero-dependency architecture, universal runtime support across Node.js, Deno, Bun, browsers, and edge functions, and a library-first design philosophy that allows library authors to add logging without imposing any burden on their users. When LogTape isn't configured, logging calls have virtually no performance impact, making it the only truly unobtrusive logging solution available.
For a comprehensive overview of LogTape's capabilities and philosophy, see our introduction guide.
Milestone achievement
We're excited to announce LogTape 1.0.0, marking a significant milestone in the library's development. This release represents our commitment to API stability and long-term support. The 1.0.0 designation signals that LogTape's core APIs are now stable and ready for production use, with any future breaking changes following semantic versioning principles.
This milestone builds upon months of refinement, community feedback, and real-world usage, establishing LogTape as a mature and reliable logging solution for JavaScript applications and libraries.
Major new features
High-performance logging infrastructure
LogTape 1.0.0 introduces several performance-oriented features designed for high-throughput production environments. The new non-blocking sink option allows console, stream, and file sinks to buffer log records and flush them asynchronously, preventing logging operations from blocking your application's main thread.
The new fromAsyncSink() function provides a clean way to integrate asynchronous logging operations while maintaining LogTape's synchronous sink interface. This enables scenarios like sending logs to remote servers or databases without blocking your application.
For file operations specifically, the new getStreamFileSink() function in the @logtape/file package leverages Node.js PassThrough streams to deliver optimal I/O performance with automatic backpressure management.
New sink integrations
This release significantly expands LogTape's integration capabilities with two major new sink packages. The @logtape/cloudwatch-logs package enables direct integration with AWS CloudWatch Logs, featuring intelligent batching, exponential backoff retry strategies, and support for structured logging through JSON Lines formatting.
The @logtape/windows-eventlog package brings native Windows Event Log support with cross-runtime compatibility across Deno, Node.js, and Bun. This integration uses runtime-optimized FFI implementations for maximum performance while maintaining proper error handling and resource cleanup.
Beautiful development experience
The new @logtape/pretty package transforms console logging into a visually appealing experience designed specifically for local development. Inspired by Signale, it features colorful emojis for each log level, smart category truncation that preserves important context, and perfect column alignment that makes logs easy to scan.
As shown above, the pretty formatter supports true color terminals with rich color schemes, configurable icons, and intelligent word wrapping that maintains visual consistency even for long messages.
Ecosystem integration
Perhaps most significantly, LogTape 1.0.0 introduces adapter packages that bridge the gap between LogTape's library-friendly design and existing logging infrastructure. The @logtape/adaptor-winston and @logtape/adaptor-pino packages allow applications using these established logging libraries to seamlessly integrate LogTape-enabled libraries without changing their existing setup.
// Quick setup with winstonimport "@logtape/adaptor-winston/install";
// Or with custom configurationimport { install } from "@logtape/adaptor-winston";import winston from "winston";const logger = winston.createLogger({/* your config */});install(logger);
These adapters preserve LogTape's structured logging capabilities while routing everything through your preferred logging system, making adoption of LogTape-enabled libraries frictionless for existing applications.
Developer experience enhancements
This release includes several quality-of-life improvements for developers working with LogTape. The new getLogLevels() function provides programmatic access to all available log levels, while the LogMethod type offers better type inference for logging methods.
Browser compatibility has been improved, particularly for the @logtape/otel package, which previously had issues in browser environments due to Node.js-specific imports. The package now works seamlessly across all JavaScript runtimes without throwing module resolution errors.
Breaking changes and migration guide
LogTape 1.0.0 includes one notable breaking change: the removal of the deprecated LoggerConfig.level property. This property was deprecated in version 0.8.0 in favor of the more descriptive LoggerConfig.lowestLevel property.
If your configuration still uses the old property, simply rename it:
// Before (deprecated){ category: ["app"], level: "info", sinks: ["console"] }
For more complex filtering requirements, consider using the LoggerConfig.filters option instead, which provides more flexibility and supports inheritance from parent loggers.
Complete package ecosystem
LogTape 1.0.0 represents the culmination of a comprehensive package ecosystem, now consisting of 11 specialized packages that address different aspects of logging infrastructure. This modular approach allows you to install only the packages you need, keeping your dependency footprint minimal while accessing powerful logging capabilities when required.
Whether you're new to LogTape or upgrading from a previous version, getting started with 1.0.0 is straightforward. For new projects, begin with a simple configuration and gradually add the packages and features you need:
Existing applications using winston or Pino can immediately benefit from LogTape-enabled libraries by installing the appropriate adapter. For comprehensive migration guidance and detailed feature documentation, visit our documentation site.
The 1.0.0 release represents not just a version number, but a commitment to the stability and maturity that production applications require. We're excited to see what you'll build with LogTape.
LogTape is a logging library designed specifically for the modern JavaScript ecosystem. It stands out with its zero-dependency architecture, universal runtime support across Node.js, Deno, Bun, browsers, and edge functions, and a library-first design philosophy that allows library authors to add logging without imposing any burden on their users. When LogTape isn't configured, logging calls have virtually no performance impact, making it the only truly unobtrusive logging solution available.
For a comprehensive overview of LogTape's capabilities and philosophy, see our introduction guide.
Milestone achievement
We're excited to announce LogTape 1.0.0, marking a significant milestone in the library's development. This release represents our commitment to API stability and long-term support. The 1.0.0 designation signals that LogTape's core APIs are now stable and ready for production use, with any future breaking changes following semantic versioning principles.
This milestone builds upon months of refinement, community feedback, and real-world usage, establishing LogTape as a mature and reliable logging solution for JavaScript applications and libraries.
Major new features
High-performance logging infrastructure
LogTape 1.0.0 introduces several performance-oriented features designed for high-throughput production environments. The new non-blocking sink option allows console, stream, and file sinks to buffer log records and flush them asynchronously, preventing logging operations from blocking your application's main thread.
The new fromAsyncSink() function provides a clean way to integrate asynchronous logging operations while maintaining LogTape's synchronous sink interface. This enables scenarios like sending logs to remote servers or databases without blocking your application.
For file operations specifically, the new getStreamFileSink() function in the @logtape/file package leverages Node.js PassThrough streams to deliver optimal I/O performance with automatic backpressure management.
New sink integrations
This release significantly expands LogTape's integration capabilities with two major new sink packages. The @logtape/cloudwatch-logs package enables direct integration with AWS CloudWatch Logs, featuring intelligent batching, exponential backoff retry strategies, and support for structured logging through JSON Lines formatting.
The @logtape/windows-eventlog package brings native Windows Event Log support with cross-runtime compatibility across Deno, Node.js, and Bun. This integration uses runtime-optimized FFI implementations for maximum performance while maintaining proper error handling and resource cleanup.
Beautiful development experience
The new @logtape/pretty package transforms console logging into a visually appealing experience designed specifically for local development. Inspired by Signale, it features colorful emojis for each log level, smart category truncation that preserves important context, and perfect column alignment that makes logs easy to scan.
As shown above, the pretty formatter supports true color terminals with rich color schemes, configurable icons, and intelligent word wrapping that maintains visual consistency even for long messages.
Ecosystem integration
Perhaps most significantly, LogTape 1.0.0 introduces adapter packages that bridge the gap between LogTape's library-friendly design and existing logging infrastructure. The @logtape/adaptor-winston and @logtape/adaptor-pino packages allow applications using these established logging libraries to seamlessly integrate LogTape-enabled libraries without changing their existing setup.
// Quick setup with winstonimport "@logtape/adaptor-winston/install";
// Or with custom configurationimport { install } from "@logtape/adaptor-winston";import winston from "winston";const logger = winston.createLogger({/* your config */});install(logger);
These adapters preserve LogTape's structured logging capabilities while routing everything through your preferred logging system, making adoption of LogTape-enabled libraries frictionless for existing applications.
Developer experience enhancements
This release includes several quality-of-life improvements for developers working with LogTape. The new getLogLevels() function provides programmatic access to all available log levels, while the LogMethod type offers better type inference for logging methods.
Browser compatibility has been improved, particularly for the @logtape/otel package, which previously had issues in browser environments due to Node.js-specific imports. The package now works seamlessly across all JavaScript runtimes without throwing module resolution errors.
Breaking changes and migration guide
LogTape 1.0.0 includes one notable breaking change: the removal of the deprecated LoggerConfig.level property. This property was deprecated in version 0.8.0 in favor of the more descriptive LoggerConfig.lowestLevel property.
If your configuration still uses the old property, simply rename it:
// Before (deprecated){ category: ["app"], level: "info", sinks: ["console"] }
For more complex filtering requirements, consider using the LoggerConfig.filters option instead, which provides more flexibility and supports inheritance from parent loggers.
Complete package ecosystem
LogTape 1.0.0 represents the culmination of a comprehensive package ecosystem, now consisting of 11 specialized packages that address different aspects of logging infrastructure. This modular approach allows you to install only the packages you need, keeping your dependency footprint minimal while accessing powerful logging capabilities when required.
Whether you're new to LogTape or upgrading from a previous version, getting started with 1.0.0 is straightforward. For new projects, begin with a simple configuration and gradually add the packages and features you need:
Existing applications using winston or Pino can immediately benefit from LogTape-enabled libraries by installing the appropriate adapter. For comprehensive migration guidance and detailed feature documentation, visit our documentation site.
The 1.0.0 release represents not just a version number, but a commitment to the stability and maturity that production applications require. We're excited to see what you'll build with LogTape.
LogTape is a logging library designed specifically for the modern JavaScript ecosystem. It stands out with its zero-dependency architecture, universal runtime support across Node.js, Deno, Bun, browsers, and edge functions, and a library-first design philosophy that allows library authors to add logging without imposing any burden on their users. When LogTape isn't configured, logging calls have virtually no performance impact, making it the only truly unobtrusive logging solution available.
For a comprehensive overview of LogTape's capabilities and philosophy, see our introduction guide.
Milestone achievement
We're excited to announce LogTape 1.0.0, marking a significant milestone in the library's development. This release represents our commitment to API stability and long-term support. The 1.0.0 designation signals that LogTape's core APIs are now stable and ready for production use, with any future breaking changes following semantic versioning principles.
This milestone builds upon months of refinement, community feedback, and real-world usage, establishing LogTape as a mature and reliable logging solution for JavaScript applications and libraries.
Major new features
High-performance logging infrastructure
LogTape 1.0.0 introduces several performance-oriented features designed for high-throughput production environments. The new non-blocking sink option allows console, stream, and file sinks to buffer log records and flush them asynchronously, preventing logging operations from blocking your application's main thread.
The new fromAsyncSink() function provides a clean way to integrate asynchronous logging operations while maintaining LogTape's synchronous sink interface. This enables scenarios like sending logs to remote servers or databases without blocking your application.
For file operations specifically, the new getStreamFileSink() function in the @logtape/file package leverages Node.js PassThrough streams to deliver optimal I/O performance with automatic backpressure management.
New sink integrations
This release significantly expands LogTape's integration capabilities with two major new sink packages. The @logtape/cloudwatch-logs package enables direct integration with AWS CloudWatch Logs, featuring intelligent batching, exponential backoff retry strategies, and support for structured logging through JSON Lines formatting.
The @logtape/windows-eventlog package brings native Windows Event Log support with cross-runtime compatibility across Deno, Node.js, and Bun. This integration uses runtime-optimized FFI implementations for maximum performance while maintaining proper error handling and resource cleanup.
Beautiful development experience
The new @logtape/pretty package transforms console logging into a visually appealing experience designed specifically for local development. Inspired by Signale, it features colorful emojis for each log level, smart category truncation that preserves important context, and perfect column alignment that makes logs easy to scan.
As shown above, the pretty formatter supports true color terminals with rich color schemes, configurable icons, and intelligent word wrapping that maintains visual consistency even for long messages.
Ecosystem integration
Perhaps most significantly, LogTape 1.0.0 introduces adapter packages that bridge the gap between LogTape's library-friendly design and existing logging infrastructure. The @logtape/adaptor-winston and @logtape/adaptor-pino packages allow applications using these established logging libraries to seamlessly integrate LogTape-enabled libraries without changing their existing setup.
// Quick setup with winstonimport "@logtape/adaptor-winston/install";
// Or with custom configurationimport { install } from "@logtape/adaptor-winston";import winston from "winston";const logger = winston.createLogger({/* your config */});install(logger);
These adapters preserve LogTape's structured logging capabilities while routing everything through your preferred logging system, making adoption of LogTape-enabled libraries frictionless for existing applications.
Developer experience enhancements
This release includes several quality-of-life improvements for developers working with LogTape. The new getLogLevels() function provides programmatic access to all available log levels, while the LogMethod type offers better type inference for logging methods.
Browser compatibility has been improved, particularly for the @logtape/otel package, which previously had issues in browser environments due to Node.js-specific imports. The package now works seamlessly across all JavaScript runtimes without throwing module resolution errors.
Breaking changes and migration guide
LogTape 1.0.0 includes one notable breaking change: the removal of the deprecated LoggerConfig.level property. This property was deprecated in version 0.8.0 in favor of the more descriptive LoggerConfig.lowestLevel property.
If your configuration still uses the old property, simply rename it:
// Before (deprecated){ category: ["app"], level: "info", sinks: ["console"] }
For more complex filtering requirements, consider using the LoggerConfig.filters option instead, which provides more flexibility and supports inheritance from parent loggers.
Complete package ecosystem
LogTape 1.0.0 represents the culmination of a comprehensive package ecosystem, now consisting of 11 specialized packages that address different aspects of logging infrastructure. This modular approach allows you to install only the packages you need, keeping your dependency footprint minimal while accessing powerful logging capabilities when required.
Whether you're new to LogTape or upgrading from a previous version, getting started with 1.0.0 is straightforward. For new projects, begin with a simple configuration and gradually add the packages and features you need:
Existing applications using winston or Pino can immediately benefit from LogTape-enabled libraries by installing the appropriate adapter. For comprehensive migration guidance and detailed feature documentation, visit our documentation site.
The 1.0.0 release represents not just a version number, but a commitment to the stability and maturity that production applications require. We're excited to see what you'll build with LogTape.
LogTape is a logging library designed specifically for the modern JavaScript ecosystem. It stands out with its zero-dependency architecture, universal runtime support across Node.js, Deno, Bun, browsers, and edge functions, and a library-first design philosophy that allows library authors to add logging without imposing any burden on their users. When LogTape isn't configured, logging calls have virtually no performance impact, making it the only truly unobtrusive logging solution available.
For a comprehensive overview of LogTape's capabilities and philosophy, see our introduction guide.
Milestone achievement
We're excited to announce LogTape 1.0.0, marking a significant milestone in the library's development. This release represents our commitment to API stability and long-term support. The 1.0.0 designation signals that LogTape's core APIs are now stable and ready for production use, with any future breaking changes following semantic versioning principles.
This milestone builds upon months of refinement, community feedback, and real-world usage, establishing LogTape as a mature and reliable logging solution for JavaScript applications and libraries.
Major new features
High-performance logging infrastructure
LogTape 1.0.0 introduces several performance-oriented features designed for high-throughput production environments. The new non-blocking sink option allows console, stream, and file sinks to buffer log records and flush them asynchronously, preventing logging operations from blocking your application's main thread.
The new fromAsyncSink() function provides a clean way to integrate asynchronous logging operations while maintaining LogTape's synchronous sink interface. This enables scenarios like sending logs to remote servers or databases without blocking your application.
For file operations specifically, the new getStreamFileSink() function in the @logtape/file package leverages Node.js PassThrough streams to deliver optimal I/O performance with automatic backpressure management.
New sink integrations
This release significantly expands LogTape's integration capabilities with two major new sink packages. The @logtape/cloudwatch-logs package enables direct integration with AWS CloudWatch Logs, featuring intelligent batching, exponential backoff retry strategies, and support for structured logging through JSON Lines formatting.
The @logtape/windows-eventlog package brings native Windows Event Log support with cross-runtime compatibility across Deno, Node.js, and Bun. This integration uses runtime-optimized FFI implementations for maximum performance while maintaining proper error handling and resource cleanup.
Beautiful development experience
The new @logtape/pretty package transforms console logging into a visually appealing experience designed specifically for local development. Inspired by Signale, it features colorful emojis for each log level, smart category truncation that preserves important context, and perfect column alignment that makes logs easy to scan.
As shown above, the pretty formatter supports true color terminals with rich color schemes, configurable icons, and intelligent word wrapping that maintains visual consistency even for long messages.
Ecosystem integration
Perhaps most significantly, LogTape 1.0.0 introduces adapter packages that bridge the gap between LogTape's library-friendly design and existing logging infrastructure. The @logtape/adaptor-winston and @logtape/adaptor-pino packages allow applications using these established logging libraries to seamlessly integrate LogTape-enabled libraries without changing their existing setup.
// Quick setup with winstonimport "@logtape/adaptor-winston/install";
// Or with custom configurationimport { install } from "@logtape/adaptor-winston";import winston from "winston";const logger = winston.createLogger({/* your config */});install(logger);
These adapters preserve LogTape's structured logging capabilities while routing everything through your preferred logging system, making adoption of LogTape-enabled libraries frictionless for existing applications.
Developer experience enhancements
This release includes several quality-of-life improvements for developers working with LogTape. The new getLogLevels() function provides programmatic access to all available log levels, while the LogMethod type offers better type inference for logging methods.
Browser compatibility has been improved, particularly for the @logtape/otel package, which previously had issues in browser environments due to Node.js-specific imports. The package now works seamlessly across all JavaScript runtimes without throwing module resolution errors.
Breaking changes and migration guide
LogTape 1.0.0 includes one notable breaking change: the removal of the deprecated LoggerConfig.level property. This property was deprecated in version 0.8.0 in favor of the more descriptive LoggerConfig.lowestLevel property.
If your configuration still uses the old property, simply rename it:
// Before (deprecated){ category: ["app"], level: "info", sinks: ["console"] }
For more complex filtering requirements, consider using the LoggerConfig.filters option instead, which provides more flexibility and supports inheritance from parent loggers.
Complete package ecosystem
LogTape 1.0.0 represents the culmination of a comprehensive package ecosystem, now consisting of 11 specialized packages that address different aspects of logging infrastructure. This modular approach allows you to install only the packages you need, keeping your dependency footprint minimal while accessing powerful logging capabilities when required.
Whether you're new to LogTape or upgrading from a previous version, getting started with 1.0.0 is straightforward. For new projects, begin with a simple configuration and gradually add the packages and features you need:
Existing applications using winston or Pino can immediately benefit from LogTape-enabled libraries by installing the appropriate adapter. For comprehensive migration guidance and detailed feature documentation, visit our documentation site.
The 1.0.0 release represents not just a version number, but a commitment to the stability and maturity that production applications require. We're excited to see what you'll build with LogTape.
LogTape is a logging library designed specifically for the modern JavaScript ecosystem. It stands out with its zero-dependency architecture, universal runtime support across Node.js, Deno, Bun, browsers, and edge functions, and a library-first design philosophy that allows library authors to add logging without imposing any burden on their users. When LogTape isn't configured, logging calls have virtually no performance impact, making it the only truly unobtrusive logging solution available.
For a comprehensive overview of LogTape's capabilities and philosophy, see our introduction guide.
Milestone achievement
We're excited to announce LogTape 1.0.0, marking a significant milestone in the library's development. This release represents our commitment to API stability and long-term support. The 1.0.0 designation signals that LogTape's core APIs are now stable and ready for production use, with any future breaking changes following semantic versioning principles.
This milestone builds upon months of refinement, community feedback, and real-world usage, establishing LogTape as a mature and reliable logging solution for JavaScript applications and libraries.
Major new features
High-performance logging infrastructure
LogTape 1.0.0 introduces several performance-oriented features designed for high-throughput production environments. The new non-blocking sink option allows console, stream, and file sinks to buffer log records and flush them asynchronously, preventing logging operations from blocking your application's main thread.
The new fromAsyncSink() function provides a clean way to integrate asynchronous logging operations while maintaining LogTape's synchronous sink interface. This enables scenarios like sending logs to remote servers or databases without blocking your application.
For file operations specifically, the new getStreamFileSink() function in the @logtape/file package leverages Node.js PassThrough streams to deliver optimal I/O performance with automatic backpressure management.
New sink integrations
This release significantly expands LogTape's integration capabilities with two major new sink packages. The @logtape/cloudwatch-logs package enables direct integration with AWS CloudWatch Logs, featuring intelligent batching, exponential backoff retry strategies, and support for structured logging through JSON Lines formatting.
The @logtape/windows-eventlog package brings native Windows Event Log support with cross-runtime compatibility across Deno, Node.js, and Bun. This integration uses runtime-optimized FFI implementations for maximum performance while maintaining proper error handling and resource cleanup.
Beautiful development experience
The new @logtape/pretty package transforms console logging into a visually appealing experience designed specifically for local development. Inspired by Signale, it features colorful emojis for each log level, smart category truncation that preserves important context, and perfect column alignment that makes logs easy to scan.
As shown above, the pretty formatter supports true color terminals with rich color schemes, configurable icons, and intelligent word wrapping that maintains visual consistency even for long messages.
Ecosystem integration
Perhaps most significantly, LogTape 1.0.0 introduces adapter packages that bridge the gap between LogTape's library-friendly design and existing logging infrastructure. The @logtape/adaptor-winston and @logtape/adaptor-pino packages allow applications using these established logging libraries to seamlessly integrate LogTape-enabled libraries without changing their existing setup.
// Quick setup with winstonimport "@logtape/adaptor-winston/install";
// Or with custom configurationimport { install } from "@logtape/adaptor-winston";import winston from "winston";const logger = winston.createLogger({/* your config */});install(logger);
These adapters preserve LogTape's structured logging capabilities while routing everything through your preferred logging system, making adoption of LogTape-enabled libraries frictionless for existing applications.
Developer experience enhancements
This release includes several quality-of-life improvements for developers working with LogTape. The new getLogLevels() function provides programmatic access to all available log levels, while the LogMethod type offers better type inference for logging methods.
Browser compatibility has been improved, particularly for the @logtape/otel package, which previously had issues in browser environments due to Node.js-specific imports. The package now works seamlessly across all JavaScript runtimes without throwing module resolution errors.
Breaking changes and migration guide
LogTape 1.0.0 includes one notable breaking change: the removal of the deprecated LoggerConfig.level property. This property was deprecated in version 0.8.0 in favor of the more descriptive LoggerConfig.lowestLevel property.
If your configuration still uses the old property, simply rename it:
// Before (deprecated){ category: ["app"], level: "info", sinks: ["console"] }
For more complex filtering requirements, consider using the LoggerConfig.filters option instead, which provides more flexibility and supports inheritance from parent loggers.
Complete package ecosystem
LogTape 1.0.0 represents the culmination of a comprehensive package ecosystem, now consisting of 11 specialized packages that address different aspects of logging infrastructure. This modular approach allows you to install only the packages you need, keeping your dependency footprint minimal while accessing powerful logging capabilities when required.
Whether you're new to LogTape or upgrading from a previous version, getting started with 1.0.0 is straightforward. For new projects, begin with a simple configuration and gradually add the packages and features you need:
Existing applications using winston or Pino can immediately benefit from LogTape-enabled libraries by installing the appropriate adapter. For comprehensive migration guidance and detailed feature documentation, visit our documentation site.
The 1.0.0 release represents not just a version number, but a commitment to the stability and maturity that production applications require. We're excited to see what you'll build with LogTape.
LogTape is a zero-dependency logging library for JavaScript and TypeScript that provides a simple yet flexible logging system. It supports multiple JavaScript runtimes (Deno, Node.js, Bun, browsers, and edge functions), features hierarchical categories, structured logging, and offers seamless integration for both applications and libraries.
What's New in 0.12.0
Trace Log Level
LogTape now includes a trace severity level, which sits below debug in the verbosity hierarchy. This addition provides finer-grained control over logging output, particularly useful for detailed execution flow tracking during development and debugging.
All standard RFC 5424 facilities (kern, user, mail, daemon, local0–7, etc.)
Automatic priority calculation based on log levels
Structured data support for log record properties
Cross-runtime compatibility with Deno, Node.js, and Bun
Configurable connection timeouts, custom hostnames, and application names
Logger Method Alias
Added Logger.warning() as an alias for Logger.warn() to ensure consistency with the LogLevel type definition. This change addresses the naming mismatch where the LogLevel union type uses "warning" while the logger method was named warn(), making metaprogramming and dynamic method invocation more straightforward.
Unified Package Releases
Starting with version 0.12.0, all LogTape packages including @logtape/otel, @logtape/sentry, and @logtape/syslog share the same version number and are released together. This ensures compatibility between packages and simplifies version management for users.
Improved Build Infrastructure
LogTape has migrated from dnt to tsdown for npm package bundling. tsdown is a library-focused bundler built on top of Rolldown, a Rust-based bundler that powers the next generation of Vite. Unlike general-purpose bundlers, tsdown is specifically optimized for building TypeScript and JavaScript libraries with minimal configuration. This change brings several benefits:
Elimination of bundler warnings in Webpack, Vite, and other build tools
Improved compatibility with modern JavaScript toolchains
Better tree-shaking support
Cleaner package output
Faster build times through Rust-based performance optimizations
Migration Guide
Updating to Trace Level
If you have code that relies on debug being the lowest severity level, you may need to update your log level configurations:
// Before{ lowestLevel: "debug" } // This was the most verbose setting// After{ lowestLevel: "trace" } // Now includes trace messages
Leveraging Buffer Configuration
To optimize file sink performance in high-throughput scenarios:
getFileSink("app.log", { bufferSize: 16384, // Larger buffer for better performance flushInterval: 10_000 // Flush every 10 seconds})
LogTape is a zero-dependency logging library for JavaScript and TypeScript that provides a simple yet flexible logging system. It supports multiple JavaScript runtimes (Deno, Node.js, Bun, browsers, and edge functions), features hierarchical categories, structured logging, and offers seamless integration for both applications and libraries.
What's New in 0.12.0
Trace Log Level
LogTape now includes a trace severity level, which sits below debug in the verbosity hierarchy. This addition provides finer-grained control over logging output, particularly useful for detailed execution flow tracking during development and debugging.
All standard RFC 5424 facilities (kern, user, mail, daemon, local0–7, etc.)
Automatic priority calculation based on log levels
Structured data support for log record properties
Cross-runtime compatibility with Deno, Node.js, and Bun
Configurable connection timeouts, custom hostnames, and application names
Logger Method Alias
Added Logger.warning() as an alias for Logger.warn() to ensure consistency with the LogLevel type definition. This change addresses the naming mismatch where the LogLevel union type uses "warning" while the logger method was named warn(), making metaprogramming and dynamic method invocation more straightforward.
Unified Package Releases
Starting with version 0.12.0, all LogTape packages including @logtape/otel, @logtape/sentry, and @logtape/syslog share the same version number and are released together. This ensures compatibility between packages and simplifies version management for users.
Improved Build Infrastructure
LogTape has migrated from dnt to tsdown for npm package bundling. tsdown is a library-focused bundler built on top of Rolldown, a Rust-based bundler that powers the next generation of Vite. Unlike general-purpose bundlers, tsdown is specifically optimized for building TypeScript and JavaScript libraries with minimal configuration. This change brings several benefits:
Elimination of bundler warnings in Webpack, Vite, and other build tools
Improved compatibility with modern JavaScript toolchains
Better tree-shaking support
Cleaner package output
Faster build times through Rust-based performance optimizations
Migration Guide
Updating to Trace Level
If you have code that relies on debug being the lowest severity level, you may need to update your log level configurations:
// Before{ lowestLevel: "debug" } // This was the most verbose setting// After{ lowestLevel: "trace" } // Now includes trace messages
Leveraging Buffer Configuration
To optimize file sink performance in high-throughput scenarios:
getFileSink("app.log", { bufferSize: 16384, // Larger buffer for better performance flushInterval: 10_000 // Flush every 10 seconds})
LogTape is a zero-dependency logging library for JavaScript and TypeScript that provides a simple yet flexible logging system. It supports multiple JavaScript runtimes (Deno, Node.js, Bun, browsers, and edge functions), features hierarchical categories, structured logging, and offers seamless integration for both applications and libraries.
What's New in 0.12.0
Trace Log Level
LogTape now includes a trace severity level, which sits below debug in the verbosity hierarchy. This addition provides finer-grained control over logging output, particularly useful for detailed execution flow tracking during development and debugging.
All standard RFC 5424 facilities (kern, user, mail, daemon, local0–7, etc.)
Automatic priority calculation based on log levels
Structured data support for log record properties
Cross-runtime compatibility with Deno, Node.js, and Bun
Configurable connection timeouts, custom hostnames, and application names
Logger Method Alias
Added Logger.warning() as an alias for Logger.warn() to ensure consistency with the LogLevel type definition. This change addresses the naming mismatch where the LogLevel union type uses "warning" while the logger method was named warn(), making metaprogramming and dynamic method invocation more straightforward.
Unified Package Releases
Starting with version 0.12.0, all LogTape packages including @logtape/otel, @logtape/sentry, and @logtape/syslog share the same version number and are released together. This ensures compatibility between packages and simplifies version management for users.
Improved Build Infrastructure
LogTape has migrated from dnt to tsdown for npm package bundling. tsdown is a library-focused bundler built on top of Rolldown, a Rust-based bundler that powers the next generation of Vite. Unlike general-purpose bundlers, tsdown is specifically optimized for building TypeScript and JavaScript libraries with minimal configuration. This change brings several benefits:
Elimination of bundler warnings in Webpack, Vite, and other build tools
Improved compatibility with modern JavaScript toolchains
Better tree-shaking support
Cleaner package output
Faster build times through Rust-based performance optimizations
Migration Guide
Updating to Trace Level
If you have code that relies on debug being the lowest severity level, you may need to update your log level configurations:
// Before{ lowestLevel: "debug" } // This was the most verbose setting// After{ lowestLevel: "trace" } // Now includes trace messages
Leveraging Buffer Configuration
To optimize file sink performance in high-throughput scenarios:
getFileSink("app.log", { bufferSize: 16384, // Larger buffer for better performance flushInterval: 10_000 // Flush every 10 seconds})
LogTape is a zero-dependency logging library for JavaScript and TypeScript that provides a simple yet flexible logging system. It supports multiple JavaScript runtimes (Deno, Node.js, Bun, browsers, and edge functions), features hierarchical categories, structured logging, and offers seamless integration for both applications and libraries.
What's New in 0.12.0
Trace Log Level
LogTape now includes a trace severity level, which sits below debug in the verbosity hierarchy. This addition provides finer-grained control over logging output, particularly useful for detailed execution flow tracking during development and debugging.
All standard RFC 5424 facilities (kern, user, mail, daemon, local0–7, etc.)
Automatic priority calculation based on log levels
Structured data support for log record properties
Cross-runtime compatibility with Deno, Node.js, and Bun
Configurable connection timeouts, custom hostnames, and application names
Logger Method Alias
Added Logger.warning() as an alias for Logger.warn() to ensure consistency with the LogLevel type definition. This change addresses the naming mismatch where the LogLevel union type uses "warning" while the logger method was named warn(), making metaprogramming and dynamic method invocation more straightforward.
Unified Package Releases
Starting with version 0.12.0, all LogTape packages including @logtape/otel, @logtape/sentry, and @logtape/syslog share the same version number and are released together. This ensures compatibility between packages and simplifies version management for users.
Improved Build Infrastructure
LogTape has migrated from dnt to tsdown for npm package bundling. tsdown is a library-focused bundler built on top of Rolldown, a Rust-based bundler that powers the next generation of Vite. Unlike general-purpose bundlers, tsdown is specifically optimized for building TypeScript and JavaScript libraries with minimal configuration. This change brings several benefits:
Elimination of bundler warnings in Webpack, Vite, and other build tools
Improved compatibility with modern JavaScript toolchains
Better tree-shaking support
Cleaner package output
Faster build times through Rust-based performance optimizations
Migration Guide
Updating to Trace Level
If you have code that relies on debug being the lowest severity level, you may need to update your log level configurations:
// Before{ lowestLevel: "debug" } // This was the most verbose setting// After{ lowestLevel: "trace" } // Now includes trace messages
Leveraging Buffer Configuration
To optimize file sink performance in high-throughput scenarios:
getFileSink("app.log", { bufferSize: 16384, // Larger buffer for better performance flushInterval: 10_000 // Flush every 10 seconds})
LogTape is a zero-dependency logging library for JavaScript and TypeScript that provides a simple yet flexible logging system. It supports multiple JavaScript runtimes (Deno, Node.js, Bun, browsers, and edge functions), features hierarchical categories, structured logging, and offers seamless integration for both applications and libraries.
What's New in 0.12.0
Trace Log Level
LogTape now includes a trace severity level, which sits below debug in the verbosity hierarchy. This addition provides finer-grained control over logging output, particularly useful for detailed execution flow tracking during development and debugging.
All standard RFC 5424 facilities (kern, user, mail, daemon, local0–7, etc.)
Automatic priority calculation based on log levels
Structured data support for log record properties
Cross-runtime compatibility with Deno, Node.js, and Bun
Configurable connection timeouts, custom hostnames, and application names
Logger Method Alias
Added Logger.warning() as an alias for Logger.warn() to ensure consistency with the LogLevel type definition. This change addresses the naming mismatch where the LogLevel union type uses "warning" while the logger method was named warn(), making metaprogramming and dynamic method invocation more straightforward.
Unified Package Releases
Starting with version 0.12.0, all LogTape packages including @logtape/otel, @logtape/sentry, and @logtape/syslog share the same version number and are released together. This ensures compatibility between packages and simplifies version management for users.
Improved Build Infrastructure
LogTape has migrated from dnt to tsdown for npm package bundling. tsdown is a library-focused bundler built on top of Rolldown, a Rust-based bundler that powers the next generation of Vite. Unlike general-purpose bundlers, tsdown is specifically optimized for building TypeScript and JavaScript libraries with minimal configuration. This change brings several benefits:
Elimination of bundler warnings in Webpack, Vite, and other build tools
Improved compatibility with modern JavaScript toolchains
Better tree-shaking support
Cleaner package output
Faster build times through Rust-based performance optimizations
Migration Guide
Updating to Trace Level
If you have code that relies on debug being the lowest severity level, you may need to update your log level configurations:
// Before{ lowestLevel: "debug" } // This was the most verbose setting// After{ lowestLevel: "trace" } // Now includes trace messages
Leveraging Buffer Configuration
To optimize file sink performance in high-throughput scenarios:
getFileSink("app.log", { bufferSize: 16384, // Larger buffer for better performance flushInterval: 10_000 // Flush every 10 seconds})
LogTape is a zero-dependency logging library for JavaScript and TypeScript that provides a simple yet flexible logging system. It supports multiple JavaScript runtimes (Deno, Node.js, Bun, browsers, and edge functions), features hierarchical categories, structured logging, and offers seamless integration for both applications and libraries.
What's New in 0.12.0
Trace Log Level
LogTape now includes a trace severity level, which sits below debug in the verbosity hierarchy. This addition provides finer-grained control over logging output, particularly useful for detailed execution flow tracking during development and debugging.
All standard RFC 5424 facilities (kern, user, mail, daemon, local0–7, etc.)
Automatic priority calculation based on log levels
Structured data support for log record properties
Cross-runtime compatibility with Deno, Node.js, and Bun
Configurable connection timeouts, custom hostnames, and application names
Logger Method Alias
Added Logger.warning() as an alias for Logger.warn() to ensure consistency with the LogLevel type definition. This change addresses the naming mismatch where the LogLevel union type uses "warning" while the logger method was named warn(), making metaprogramming and dynamic method invocation more straightforward.
Unified Package Releases
Starting with version 0.12.0, all LogTape packages including @logtape/otel, @logtape/sentry, and @logtape/syslog share the same version number and are released together. This ensures compatibility between packages and simplifies version management for users.
Improved Build Infrastructure
LogTape has migrated from dnt to tsdown for npm package bundling. tsdown is a library-focused bundler built on top of Rolldown, a Rust-based bundler that powers the next generation of Vite. Unlike general-purpose bundlers, tsdown is specifically optimized for building TypeScript and JavaScript libraries with minimal configuration. This change brings several benefits:
Elimination of bundler warnings in Webpack, Vite, and other build tools
Improved compatibility with modern JavaScript toolchains
Better tree-shaking support
Cleaner package output
Faster build times through Rust-based performance optimizations
Migration Guide
Updating to Trace Level
If you have code that relies on debug being the lowest severity level, you may need to update your log level configurations:
// Before{ lowestLevel: "debug" } // This was the most verbose setting// After{ lowestLevel: "trace" } // Now includes trace messages
Leveraging Buffer Configuration
To optimize file sink performance in high-throughput scenarios:
getFileSink("app.log", { bufferSize: 16384, // Larger buffer for better performance flushInterval: 10_000 // Flush every 10 seconds})
LogTape is a zero-dependency logging library for JavaScript and TypeScript that works across all runtimes.
We're excited to announce the release of LogTape 0.11.0, which introduces significant enhancements to structured logging capabilities and adds a new JSON Lines formatter for better log processing.
New features and enhancements
Enhanced structured logging
LogTape 0.11.0 brings major improvements to structured logging, making it easier and more flexible to work with structured data in your logs.
Direct object logging
You can now log structured data directly by passing an object as the first argument to any log method:
logger.info({ userId: 123456, username: "johndoe", loginTime: new Date(),});
This creates a log entry with the object properties as structured fields, making your logs more machine-readable and searchable.
Universal property interpolation with {*}
A new special placeholder {*} allows you to interpolate all properties from your structured data at once:
logger.info("User logged in with properties {*}", { userId: 123456, username: "johndoe", loginTime: new Date(),});
This is particularly useful when you want to include all available context without explicitly naming each property in your message template.
Streamlined logging methods
All logging methods (debug, info, warn, error, fatal) now support the new object-first syntax as a convenient shorthand for structured logging with the {*} placeholder.
JSON Lines formatter
LogTape now includes built-in support for JSON Lines (also known as JSONL or NDJSON) format, a popular choice for structured logging in modern applications:
import { jsonLinesFormatter } from "@logtape/logtape";import { getFileSink } from "@logtape/file";await configure({ sinks: { jsonl: getFileSink("app.jsonl", { formatter: jsonLinesFormatter }), }, // ... rest of configuration});
The JSON Lines formatter outputs each log record as a JSON object on a separate line, making it ideal for log aggregation systems and analysis tools.
LogTape is a zero-dependency logging library for JavaScript and TypeScript that works across all runtimes.
We're excited to announce the release of LogTape 0.11.0, which introduces significant enhancements to structured logging capabilities and adds a new JSON Lines formatter for better log processing.
New features and enhancements
Enhanced structured logging
LogTape 0.11.0 brings major improvements to structured logging, making it easier and more flexible to work with structured data in your logs.
Direct object logging
You can now log structured data directly by passing an object as the first argument to any log method:
logger.info({ userId: 123456, username: "johndoe", loginTime: new Date(),});
This creates a log entry with the object properties as structured fields, making your logs more machine-readable and searchable.
Universal property interpolation with {*}
A new special placeholder {*} allows you to interpolate all properties from your structured data at once:
logger.info("User logged in with properties {*}", { userId: 123456, username: "johndoe", loginTime: new Date(),});
This is particularly useful when you want to include all available context without explicitly naming each property in your message template.
Streamlined logging methods
All logging methods (debug, info, warn, error, fatal) now support the new object-first syntax as a convenient shorthand for structured logging with the {*} placeholder.
JSON Lines formatter
LogTape now includes built-in support for JSON Lines (also known as JSONL or NDJSON) format, a popular choice for structured logging in modern applications:
import { jsonLinesFormatter } from "@logtape/logtape";import { getFileSink } from "@logtape/file";await configure({ sinks: { jsonl: getFileSink("app.jsonl", { formatter: jsonLinesFormatter }), }, // ... rest of configuration});
The JSON Lines formatter outputs each log record as a JSON object on a separate line, making it ideal for log aggregation systems and analysis tools.
In the diverse and ever-evolving JavaScript ecosystem, logging remains a critical component for development, debugging, and monitoring applications. While numerous logging libraries exist, LogTape stands out with its unique combination of simplicity, flexibility, and cross-runtime compatibility. Let's explore why LogTape deserves consideration for your next JavaScript or TypeScript project—whether you're building an application or a library.
Zero Dependencies: A Lightweight Footprint
One of LogTape's most compelling features is its complete absence of dependencies. In an era where “dependency hell” plagues many JavaScript projects, LogTape offers a refreshing alternative:
// No additional packages to install beyond LogTape itselfimport { configure, getConsoleSink, getLogger } from "@logtape/logtape";
This zero-dependency approach provides several advantages:
Reduced bundle size
No transitive dependencies means smaller packages
Enhanced stability
No risk of breaking changes from upstream dependencies
Simplified security
Fewer potential vulnerabilities from third-party code
Lower integration overhead
Particularly valuable for library authors who don't want to burden users with additional dependencies
Runtime Diversity: Write Once, Log Everywhere
While many popular logging libraries focus primarily on Node.js, LogTape provides seamless support across diverse JavaScript runtimes:
This runtime flexibility means you can use consistent logging patterns regardless of your deployment environment:
// Same API works seamlessly across all JavaScript runtimesimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-service", "user-management"]);// Works in Node.js, Deno, Bun, browsers, or edge functionslogger.info`User ${userId} logged in successfully`;
For teams working across multiple platforms or projects transitioning between runtimes, this consistency is invaluable. No need to learn different logging libraries or approaches—LogTape works the same way everywhere.
Hierarchical Categories: Fine-Grained Control
LogTape's hierarchical category system represents a standout feature that's surprisingly rare among JavaScript logging libraries. Categories allow you to organize logs in a tree-like structure:
This hierarchical approach offers powerful benefits:
Targeted filtering
Configure different log levels for different parts of your application
Inheritance
Child loggers inherit settings from parents, reducing configuration overhead
Organizational clarity
Logs naturally follow your application's module structure
Here's how you might configure logging levels for different categories:
await configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log"), }, loggers: [ // Base configuration for all app logs { category: ["my-app"], lowestLevel: "info", sinks: ["console", "file"] }, // More verbose logging just for database components { category: ["my-app", "database"], lowestLevel: "debug", sinks: ["file"] } ]});
With this configuration, all application logs at "info" level and above go to both console and file, while database-specific logs include more detailed "debug" level information, but only in the log file.
Structured Logging: Beyond Simple Text
Modern logging goes beyond simple text strings. LogTape embraces structured logging, which treats log entries as data objects rather than plain text:
The function is only evaluated if the debug level is enabled, preventing unnecessary computation for suppressed log levels.
Extremely Simple Sinks and Filters: Minimal Boilerplate
LogTape's approach to extensibility is remarkably straightforward. Creating custom sinks (output destinations) and filters requires minimal boilerplate code.
Dead Simple Sinks
A sink in LogTape is just a function that receives a log record:
// Creating a custom sink is as simple as defining a functionconst mySink = (record) => { const timestamp = new Date(record.timestamp).toISOString(); const level = record.level.toUpperCase(); const category = record.category.join('.'); // Send to your custom destination myCustomLogService.send({ time: timestamp, priority: level, component: category, message: record.message, ...record.properties });};// Use your custom sink in configurationawait configure({ sinks: { console: getConsoleSink(), custom: mySink }, loggers: [ { category: ["my-app"], sinks: ["console", "custom"] } ]});
Compare this with other libraries that require extending classes, implementing multiple methods, or following specific patterns. LogTape's approach is refreshingly straightforward.
Simple Filters
Similarly, filters in LogTape are just functions that return a Boolean:
// Filter that only passes high-priority or specific component logsconst importantLogsFilter = (record) => { // Always include errors if (record.level === "error" || record.level === "fatal") { return true; } // Always include payment-related logs if (record.category.includes("payments")) { return true; } // Filter out other logs return false;};await configure({ // ...sinks configuration filters: { important: importantLogsFilter }, loggers: [ { category: ["my-app"], sinks: ["alertSystem"], filters: ["important"] } ]});
LogTape also provides a convenient shorthand for level-based filtering:
await configure({ // ...sinks configuration filters: { // This creates a filter for "warning" level and above warningAndAbove: "warning" }, loggers: [ { category: ["my-app"], sinks: ["console"], filters: ["warningAndAbove"] } ]});
Perfect for Library Authors
LogTape is uniquely well-suited for library authors who want to incorporate logging without burdening their users. The core philosophy is simple:
The key point is that the library never calls configure(). Instead, it provides useful log output points with appropriate levels and contextual data.
Applications using the library can then decide exactly how to handle these logs:
// Application codeimport { configure, getConsoleSink } from "@logtape/logtape";import { Database } from "my-awesome-lib";// Configure how logs should be handledawait configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log") }, loggers: [ // Handle all library logs { category: ["my-awesome-lib"], lowestLevel: "info", sinks: ["file"] }, // More verbose for database component during development { category: ["my-awesome-lib", "database"], lowestLevel: "debug", sinks: ["console", "file"] } ]});// Use the libraryconst db = new Database("localhost", 5432, "user");db.connect();
This separation of concerns offers several benefits:
Library users have complete control over log handling
Libraries can provide rich logging without imposing implementation details
No risk of conflict with application logging configurations
Libraries can be "noisy" internally while allowing applications to filter as needed
Contexts for Richer Logging
LogTape provides context mechanisms for adding consistent properties across multiple log messages. This is particularly valuable for tracing requests through a system:
Explicit Contexts
const logger = getLogger(["my-app", "api"]);// Create a logger with contextconst requestLogger = logger.with({ requestId: "abc-123", userId: 42, endpoint: "/users"});// All logs from this logger include the context propertiesrequestLogger.info("Processing request");requestLogger.debug("Validating input");requestLogger.info("Request completed", { durationMs: 120 });
Implicit Contexts (v0.7.0+)
For cases where you want context to apply across function calls without explicit passing:
import { getLogger, withContext } from "@logtape/logtape";function handleRequest(req, res) { withContext({ requestId: req.id, userId: req.user?.id }, () => { // All logs within this function and any functions it calls // will automatically include the context properties processRequest(req, res); });}function processRequest(req, res) { // No need to pass context - it's automatically available getLogger(["my-app", "processor"]).info("Processing data"); // Call other functions that will also inherit the context validateInput(req.body);}function validateInput(data) { // This log also gets the requestId and userId getLogger(["my-app", "validator"]).debug("Validating input", { data });}
This implicit context capability is invaluable for tracing requests through multiple layers of code without manually threading context through every function call.
When LogTape Might Not Be Your Best Choice
While LogTape offers compelling advantages for many use cases, it's not universally the best choice:
Extreme performance requirements
If your application logs tens of thousands of entries per second and raw performance is the top priority, specialized high-performance libraries like Pino may be more suitable with their focus on optimized logging throughput.
Extensive pre-built integrations
If you need immediate integration with numerous specific systems (Elasticsearch, Graylog, etc.) without writing any custom code, Winston's rich ecosystem of transports might provide a faster starting point.
Legacy systems with specific logging requirements
If you're maintaining systems built around specific logging patterns from Java or other environments, purpose-built libraries like Log4js might offer more familiar APIs.
Web browser-only applications with minimal logging needs
For extremely simple web browser-only logging needs where you just want basic console output with levels, even simpler libraries like loglevel might be sufficient.
Conclusion
LogTape stands out in the crowded JavaScript logging landscape by offering a unique combination of features that address real-world development challenges:
Zero dependencies for a lightweight, secure foundation
Runtime diversity supporting Node.js, Deno, Bun, browsers, and edge functions
Hierarchical categories for better log organization and filtering
Structured logging for improved analysis and searchability
Simple extension mechanisms with minimal boilerplate
Library-friendly design that respects separation of concerns
Whether you're building applications or libraries, working across multiple JavaScript runtimes, or simply seeking a clean, well-designed logging solution, LogTape deserves serious consideration. Its thoughtful design balances simplicity with powerful features, avoiding common pitfalls of JavaScript logging libraries.
We're pleased to announce the release of LogTape 0.10.0 today. This version introduces several significant enhancements to improve security, flexibility, and usability.
What is LogTape?
LogTape is a simple, zero-dependency logging library for JavaScript with support for multiple runtimes (Node.js, Deno, Bun, browsers, and edge functions). It features structured logging, hierarchical categories, template literals, and is designed to be used in both applications and libraries.
Key Highlights
New Data Redaction Package
The most notable addition in this release is the new @logtape/redaction package, designed to help protect sensitive information in your logs. This package provides two complementary approaches to redaction:
Pattern-based redaction: Uses regular expressions to identify and redact sensitive patterns like credit card numbers, email addresses, and tokens in formatted log output.
Field-based redaction: Identifies and redacts sensitive fields by their names in structured log data.
The package includes several built-in patterns for common sensitive data types:
Credit card numbers
Email addresses
JSON Web Tokens (JWTs)
U.S. Social Security numbers
South Korean resident registration numbers
Both approaches can be used independently or combined for maximum security. Comprehensive documentation for these features is available in the Data redaction section of the manual.
Timestamp Formatting Improvements
Text formatters now support omitting timestamps entirely from formatted messages. The TextFormatterOptions.timestamp option has been extended to include "none" and "disabled" values, giving you more control over log output format.
Lazy File Sink Option
A new FileSinkOptions.lazy option has been added, allowing file sinks to open files only when actually needed, which can improve resource utilization.
Config Error Detection
The configure() and configureSync() functions now check for duplicate logger configurations with the same category and throw a ConfigError when detected. This prevents unintended overriding of logger configurations.
Acknowledgments
We'd like to thank our external contributors who helped make this release possible:
Ooker for implementing the ability to omit timestamps from formatted messages (#35)
We're pleased to announce the release of LogTape 0.10.0 today. This version introduces several significant enhancements to improve security, flexibility, and usability.
What is LogTape?
LogTape is a simple, zero-dependency logging library for JavaScript with support for multiple runtimes (Node.js, Deno, Bun, browsers, and edge functions). It features structured logging, hierarchical categories, template literals, and is designed to be used in both applications and libraries.
Key Highlights
New Data Redaction Package
The most notable addition in this release is the new @logtape/redaction package, designed to help protect sensitive information in your logs. This package provides two complementary approaches to redaction:
Pattern-based redaction: Uses regular expressions to identify and redact sensitive patterns like credit card numbers, email addresses, and tokens in formatted log output.
Field-based redaction: Identifies and redacts sensitive fields by their names in structured log data.
The package includes several built-in patterns for common sensitive data types:
Credit card numbers
Email addresses
JSON Web Tokens (JWTs)
U.S. Social Security numbers
South Korean resident registration numbers
Both approaches can be used independently or combined for maximum security. Comprehensive documentation for these features is available in the Data redaction section of the manual.
Timestamp Formatting Improvements
Text formatters now support omitting timestamps entirely from formatted messages. The TextFormatterOptions.timestamp option has been extended to include "none" and "disabled" values, giving you more control over log output format.
Lazy File Sink Option
A new FileSinkOptions.lazy option has been added, allowing file sinks to open files only when actually needed, which can improve resource utilization.
Config Error Detection
The configure() and configureSync() functions now check for duplicate logger configurations with the same category and throw a ConfigError when detected. This prevents unintended overriding of logger configurations.
Acknowledgments
We'd like to thank our external contributors who helped make this release possible:
Ooker for implementing the ability to omit timestamps from formatted messages (#35)
We're pleased to announce the release of LogTape 0.10.0 today. This version introduces several significant enhancements to improve security, flexibility, and usability.
What is LogTape?
LogTape is a simple, zero-dependency logging library for JavaScript with support for multiple runtimes (Node.js, Deno, Bun, browsers, and edge functions). It features structured logging, hierarchical categories, template literals, and is designed to be used in both applications and libraries.
Key Highlights
New Data Redaction Package
The most notable addition in this release is the new @logtape/redaction package, designed to help protect sensitive information in your logs. This package provides two complementary approaches to redaction:
Pattern-based redaction: Uses regular expressions to identify and redact sensitive patterns like credit card numbers, email addresses, and tokens in formatted log output.
Field-based redaction: Identifies and redacts sensitive fields by their names in structured log data.
The package includes several built-in patterns for common sensitive data types:
Credit card numbers
Email addresses
JSON Web Tokens (JWTs)
U.S. Social Security numbers
South Korean resident registration numbers
Both approaches can be used independently or combined for maximum security. Comprehensive documentation for these features is available in the Data redaction section of the manual.
Timestamp Formatting Improvements
Text formatters now support omitting timestamps entirely from formatted messages. The TextFormatterOptions.timestamp option has been extended to include "none" and "disabled" values, giving you more control over log output format.
Lazy File Sink Option
A new FileSinkOptions.lazy option has been added, allowing file sinks to open files only when actually needed, which can improve resource utilization.
Config Error Detection
The configure() and configureSync() functions now check for duplicate logger configurations with the same category and throw a ConfigError when detected. This prevents unintended overriding of logger configurations.
Acknowledgments
We'd like to thank our external contributors who helped make this release possible:
Ooker for implementing the ability to omit timestamps from formatted messages (#35)
We're pleased to announce the release of LogTape 0.10.0 today. This version introduces several significant enhancements to improve security, flexibility, and usability.
What is LogTape?
LogTape is a simple, zero-dependency logging library for JavaScript with support for multiple runtimes (Node.js, Deno, Bun, browsers, and edge functions). It features structured logging, hierarchical categories, template literals, and is designed to be used in both applications and libraries.
Key Highlights
New Data Redaction Package
The most notable addition in this release is the new @logtape/redaction package, designed to help protect sensitive information in your logs. This package provides two complementary approaches to redaction:
Pattern-based redaction: Uses regular expressions to identify and redact sensitive patterns like credit card numbers, email addresses, and tokens in formatted log output.
Field-based redaction: Identifies and redacts sensitive fields by their names in structured log data.
The package includes several built-in patterns for common sensitive data types:
Credit card numbers
Email addresses
JSON Web Tokens (JWTs)
U.S. Social Security numbers
South Korean resident registration numbers
Both approaches can be used independently or combined for maximum security. Comprehensive documentation for these features is available in the Data redaction section of the manual.
Timestamp Formatting Improvements
Text formatters now support omitting timestamps entirely from formatted messages. The TextFormatterOptions.timestamp option has been extended to include "none" and "disabled" values, giving you more control over log output format.
Lazy File Sink Option
A new FileSinkOptions.lazy option has been added, allowing file sinks to open files only when actually needed, which can improve resource utilization.
Config Error Detection
The configure() and configureSync() functions now check for duplicate logger configurations with the same category and throw a ConfigError when detected. This prevents unintended overriding of logger configurations.
Acknowledgments
We'd like to thank our external contributors who helped make this release possible:
Ooker for implementing the ability to omit timestamps from formatted messages (#35)
We're pleased to announce the release of LogTape 0.10.0 today. This version introduces several significant enhancements to improve security, flexibility, and usability.
What is LogTape?
LogTape is a simple, zero-dependency logging library for JavaScript with support for multiple runtimes (Node.js, Deno, Bun, browsers, and edge functions). It features structured logging, hierarchical categories, template literals, and is designed to be used in both applications and libraries.
Key Highlights
New Data Redaction Package
The most notable addition in this release is the new @logtape/redaction package, designed to help protect sensitive information in your logs. This package provides two complementary approaches to redaction:
Pattern-based redaction: Uses regular expressions to identify and redact sensitive patterns like credit card numbers, email addresses, and tokens in formatted log output.
Field-based redaction: Identifies and redacts sensitive fields by their names in structured log data.
The package includes several built-in patterns for common sensitive data types:
Credit card numbers
Email addresses
JSON Web Tokens (JWTs)
U.S. Social Security numbers
South Korean resident registration numbers
Both approaches can be used independently or combined for maximum security. Comprehensive documentation for these features is available in the Data redaction section of the manual.
Timestamp Formatting Improvements
Text formatters now support omitting timestamps entirely from formatted messages. The TextFormatterOptions.timestamp option has been extended to include "none" and "disabled" values, giving you more control over log output format.
Lazy File Sink Option
A new FileSinkOptions.lazy option has been added, allowing file sinks to open files only when actually needed, which can improve resource utilization.
Config Error Detection
The configure() and configureSync() functions now check for duplicate logger configurations with the same category and throw a ConfigError when detected. This prevents unintended overriding of logger configurations.
Acknowledgments
We'd like to thank our external contributors who helped make this release possible:
Ooker for implementing the ability to omit timestamps from formatted messages (#35)
In the diverse and ever-evolving JavaScript ecosystem, logging remains a critical component for development, debugging, and monitoring applications. While numerous logging libraries exist, LogTape stands out with its unique combination of simplicity, flexibility, and cross-runtime compatibility. Let's explore why LogTape deserves consideration for your next JavaScript or TypeScript project—whether you're building an application or a library.
Zero Dependencies: A Lightweight Footprint
One of LogTape's most compelling features is its complete absence of dependencies. In an era where “dependency hell” plagues many JavaScript projects, LogTape offers a refreshing alternative:
// No additional packages to install beyond LogTape itselfimport { configure, getConsoleSink, getLogger } from "@logtape/logtape";
This zero-dependency approach provides several advantages:
Reduced bundle size
No transitive dependencies means smaller packages
Enhanced stability
No risk of breaking changes from upstream dependencies
Simplified security
Fewer potential vulnerabilities from third-party code
Lower integration overhead
Particularly valuable for library authors who don't want to burden users with additional dependencies
Runtime Diversity: Write Once, Log Everywhere
While many popular logging libraries focus primarily on Node.js, LogTape provides seamless support across diverse JavaScript runtimes:
This runtime flexibility means you can use consistent logging patterns regardless of your deployment environment:
// Same API works seamlessly across all JavaScript runtimesimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-service", "user-management"]);// Works in Node.js, Deno, Bun, browsers, or edge functionslogger.info`User ${userId} logged in successfully`;
For teams working across multiple platforms or projects transitioning between runtimes, this consistency is invaluable. No need to learn different logging libraries or approaches—LogTape works the same way everywhere.
Hierarchical Categories: Fine-Grained Control
LogTape's hierarchical category system represents a standout feature that's surprisingly rare among JavaScript logging libraries. Categories allow you to organize logs in a tree-like structure:
This hierarchical approach offers powerful benefits:
Targeted filtering
Configure different log levels for different parts of your application
Inheritance
Child loggers inherit settings from parents, reducing configuration overhead
Organizational clarity
Logs naturally follow your application's module structure
Here's how you might configure logging levels for different categories:
await configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log"), }, loggers: [ // Base configuration for all app logs { category: ["my-app"], lowestLevel: "info", sinks: ["console", "file"] }, // More verbose logging just for database components { category: ["my-app", "database"], lowestLevel: "debug", sinks: ["file"] } ]});
With this configuration, all application logs at "info" level and above go to both console and file, while database-specific logs include more detailed "debug" level information, but only in the log file.
Structured Logging: Beyond Simple Text
Modern logging goes beyond simple text strings. LogTape embraces structured logging, which treats log entries as data objects rather than plain text:
The function is only evaluated if the debug level is enabled, preventing unnecessary computation for suppressed log levels.
Extremely Simple Sinks and Filters: Minimal Boilerplate
LogTape's approach to extensibility is remarkably straightforward. Creating custom sinks (output destinations) and filters requires minimal boilerplate code.
Dead Simple Sinks
A sink in LogTape is just a function that receives a log record:
// Creating a custom sink is as simple as defining a functionconst mySink = (record) => { const timestamp = new Date(record.timestamp).toISOString(); const level = record.level.toUpperCase(); const category = record.category.join('.'); // Send to your custom destination myCustomLogService.send({ time: timestamp, priority: level, component: category, message: record.message, ...record.properties });};// Use your custom sink in configurationawait configure({ sinks: { console: getConsoleSink(), custom: mySink }, loggers: [ { category: ["my-app"], sinks: ["console", "custom"] } ]});
Compare this with other libraries that require extending classes, implementing multiple methods, or following specific patterns. LogTape's approach is refreshingly straightforward.
Simple Filters
Similarly, filters in LogTape are just functions that return a Boolean:
// Filter that only passes high-priority or specific component logsconst importantLogsFilter = (record) => { // Always include errors if (record.level === "error" || record.level === "fatal") { return true; } // Always include payment-related logs if (record.category.includes("payments")) { return true; } // Filter out other logs return false;};await configure({ // ...sinks configuration filters: { important: importantLogsFilter }, loggers: [ { category: ["my-app"], sinks: ["alertSystem"], filters: ["important"] } ]});
LogTape also provides a convenient shorthand for level-based filtering:
await configure({ // ...sinks configuration filters: { // This creates a filter for "warning" level and above warningAndAbove: "warning" }, loggers: [ { category: ["my-app"], sinks: ["console"], filters: ["warningAndAbove"] } ]});
Perfect for Library Authors
LogTape is uniquely well-suited for library authors who want to incorporate logging without burdening their users. The core philosophy is simple:
The key point is that the library never calls configure(). Instead, it provides useful log output points with appropriate levels and contextual data.
Applications using the library can then decide exactly how to handle these logs:
// Application codeimport { configure, getConsoleSink } from "@logtape/logtape";import { Database } from "my-awesome-lib";// Configure how logs should be handledawait configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log") }, loggers: [ // Handle all library logs { category: ["my-awesome-lib"], lowestLevel: "info", sinks: ["file"] }, // More verbose for database component during development { category: ["my-awesome-lib", "database"], lowestLevel: "debug", sinks: ["console", "file"] } ]});// Use the libraryconst db = new Database("localhost", 5432, "user");db.connect();
This separation of concerns offers several benefits:
Library users have complete control over log handling
Libraries can provide rich logging without imposing implementation details
No risk of conflict with application logging configurations
Libraries can be "noisy" internally while allowing applications to filter as needed
Contexts for Richer Logging
LogTape provides context mechanisms for adding consistent properties across multiple log messages. This is particularly valuable for tracing requests through a system:
Explicit Contexts
const logger = getLogger(["my-app", "api"]);// Create a logger with contextconst requestLogger = logger.with({ requestId: "abc-123", userId: 42, endpoint: "/users"});// All logs from this logger include the context propertiesrequestLogger.info("Processing request");requestLogger.debug("Validating input");requestLogger.info("Request completed", { durationMs: 120 });
Implicit Contexts (v0.7.0+)
For cases where you want context to apply across function calls without explicit passing:
import { getLogger, withContext } from "@logtape/logtape";function handleRequest(req, res) { withContext({ requestId: req.id, userId: req.user?.id }, () => { // All logs within this function and any functions it calls // will automatically include the context properties processRequest(req, res); });}function processRequest(req, res) { // No need to pass context - it's automatically available getLogger(["my-app", "processor"]).info("Processing data"); // Call other functions that will also inherit the context validateInput(req.body);}function validateInput(data) { // This log also gets the requestId and userId getLogger(["my-app", "validator"]).debug("Validating input", { data });}
This implicit context capability is invaluable for tracing requests through multiple layers of code without manually threading context through every function call.
When LogTape Might Not Be Your Best Choice
While LogTape offers compelling advantages for many use cases, it's not universally the best choice:
Extreme performance requirements
If your application logs tens of thousands of entries per second and raw performance is the top priority, specialized high-performance libraries like Pino may be more suitable with their focus on optimized logging throughput.
Extensive pre-built integrations
If you need immediate integration with numerous specific systems (Elasticsearch, Graylog, etc.) without writing any custom code, Winston's rich ecosystem of transports might provide a faster starting point.
Legacy systems with specific logging requirements
If you're maintaining systems built around specific logging patterns from Java or other environments, purpose-built libraries like Log4js might offer more familiar APIs.
Web browser-only applications with minimal logging needs
For extremely simple web browser-only logging needs where you just want basic console output with levels, even simpler libraries like loglevel might be sufficient.
Conclusion
LogTape stands out in the crowded JavaScript logging landscape by offering a unique combination of features that address real-world development challenges:
Zero dependencies for a lightweight, secure foundation
Runtime diversity supporting Node.js, Deno, Bun, browsers, and edge functions
Hierarchical categories for better log organization and filtering
Structured logging for improved analysis and searchability
Simple extension mechanisms with minimal boilerplate
Library-friendly design that respects separation of concerns
Whether you're building applications or libraries, working across multiple JavaScript runtimes, or simply seeking a clean, well-designed logging solution, LogTape deserves serious consideration. Its thoughtful design balances simplicity with powerful features, avoiding common pitfalls of JavaScript logging libraries.
In the diverse and ever-evolving JavaScript ecosystem, logging remains a critical component for development, debugging, and monitoring applications. While numerous logging libraries exist, LogTape stands out with its unique combination of simplicity, flexibility, and cross-runtime compatibility. Let's explore why LogTape deserves consideration for your next JavaScript or TypeScript project—whether you're building an application or a library.
Zero Dependencies: A Lightweight Footprint
One of LogTape's most compelling features is its complete absence of dependencies. In an era where “dependency hell” plagues many JavaScript projects, LogTape offers a refreshing alternative:
// No additional packages to install beyond LogTape itselfimport { configure, getConsoleSink, getLogger } from "@logtape/logtape";
This zero-dependency approach provides several advantages:
Reduced bundle size
No transitive dependencies means smaller packages
Enhanced stability
No risk of breaking changes from upstream dependencies
Simplified security
Fewer potential vulnerabilities from third-party code
Lower integration overhead
Particularly valuable for library authors who don't want to burden users with additional dependencies
Runtime Diversity: Write Once, Log Everywhere
While many popular logging libraries focus primarily on Node.js, LogTape provides seamless support across diverse JavaScript runtimes:
This runtime flexibility means you can use consistent logging patterns regardless of your deployment environment:
// Same API works seamlessly across all JavaScript runtimesimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-service", "user-management"]);// Works in Node.js, Deno, Bun, browsers, or edge functionslogger.info`User ${userId} logged in successfully`;
For teams working across multiple platforms or projects transitioning between runtimes, this consistency is invaluable. No need to learn different logging libraries or approaches—LogTape works the same way everywhere.
Hierarchical Categories: Fine-Grained Control
LogTape's hierarchical category system represents a standout feature that's surprisingly rare among JavaScript logging libraries. Categories allow you to organize logs in a tree-like structure:
This hierarchical approach offers powerful benefits:
Targeted filtering
Configure different log levels for different parts of your application
Inheritance
Child loggers inherit settings from parents, reducing configuration overhead
Organizational clarity
Logs naturally follow your application's module structure
Here's how you might configure logging levels for different categories:
await configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log"), }, loggers: [ // Base configuration for all app logs { category: ["my-app"], lowestLevel: "info", sinks: ["console", "file"] }, // More verbose logging just for database components { category: ["my-app", "database"], lowestLevel: "debug", sinks: ["file"] } ]});
With this configuration, all application logs at "info" level and above go to both console and file, while database-specific logs include more detailed "debug" level information, but only in the log file.
Structured Logging: Beyond Simple Text
Modern logging goes beyond simple text strings. LogTape embraces structured logging, which treats log entries as data objects rather than plain text:
The function is only evaluated if the debug level is enabled, preventing unnecessary computation for suppressed log levels.
Extremely Simple Sinks and Filters: Minimal Boilerplate
LogTape's approach to extensibility is remarkably straightforward. Creating custom sinks (output destinations) and filters requires minimal boilerplate code.
Dead Simple Sinks
A sink in LogTape is just a function that receives a log record:
// Creating a custom sink is as simple as defining a functionconst mySink = (record) => { const timestamp = new Date(record.timestamp).toISOString(); const level = record.level.toUpperCase(); const category = record.category.join('.'); // Send to your custom destination myCustomLogService.send({ time: timestamp, priority: level, component: category, message: record.message, ...record.properties });};// Use your custom sink in configurationawait configure({ sinks: { console: getConsoleSink(), custom: mySink }, loggers: [ { category: ["my-app"], sinks: ["console", "custom"] } ]});
Compare this with other libraries that require extending classes, implementing multiple methods, or following specific patterns. LogTape's approach is refreshingly straightforward.
Simple Filters
Similarly, filters in LogTape are just functions that return a Boolean:
// Filter that only passes high-priority or specific component logsconst importantLogsFilter = (record) => { // Always include errors if (record.level === "error" || record.level === "fatal") { return true; } // Always include payment-related logs if (record.category.includes("payments")) { return true; } // Filter out other logs return false;};await configure({ // ...sinks configuration filters: { important: importantLogsFilter }, loggers: [ { category: ["my-app"], sinks: ["alertSystem"], filters: ["important"] } ]});
LogTape also provides a convenient shorthand for level-based filtering:
await configure({ // ...sinks configuration filters: { // This creates a filter for "warning" level and above warningAndAbove: "warning" }, loggers: [ { category: ["my-app"], sinks: ["console"], filters: ["warningAndAbove"] } ]});
Perfect for Library Authors
LogTape is uniquely well-suited for library authors who want to incorporate logging without burdening their users. The core philosophy is simple:
The key point is that the library never calls configure(). Instead, it provides useful log output points with appropriate levels and contextual data.
Applications using the library can then decide exactly how to handle these logs:
// Application codeimport { configure, getConsoleSink } from "@logtape/logtape";import { Database } from "my-awesome-lib";// Configure how logs should be handledawait configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log") }, loggers: [ // Handle all library logs { category: ["my-awesome-lib"], lowestLevel: "info", sinks: ["file"] }, // More verbose for database component during development { category: ["my-awesome-lib", "database"], lowestLevel: "debug", sinks: ["console", "file"] } ]});// Use the libraryconst db = new Database("localhost", 5432, "user");db.connect();
This separation of concerns offers several benefits:
Library users have complete control over log handling
Libraries can provide rich logging without imposing implementation details
No risk of conflict with application logging configurations
Libraries can be "noisy" internally while allowing applications to filter as needed
Contexts for Richer Logging
LogTape provides context mechanisms for adding consistent properties across multiple log messages. This is particularly valuable for tracing requests through a system:
Explicit Contexts
const logger = getLogger(["my-app", "api"]);// Create a logger with contextconst requestLogger = logger.with({ requestId: "abc-123", userId: 42, endpoint: "/users"});// All logs from this logger include the context propertiesrequestLogger.info("Processing request");requestLogger.debug("Validating input");requestLogger.info("Request completed", { durationMs: 120 });
Implicit Contexts (v0.7.0+)
For cases where you want context to apply across function calls without explicit passing:
import { getLogger, withContext } from "@logtape/logtape";function handleRequest(req, res) { withContext({ requestId: req.id, userId: req.user?.id }, () => { // All logs within this function and any functions it calls // will automatically include the context properties processRequest(req, res); });}function processRequest(req, res) { // No need to pass context - it's automatically available getLogger(["my-app", "processor"]).info("Processing data"); // Call other functions that will also inherit the context validateInput(req.body);}function validateInput(data) { // This log also gets the requestId and userId getLogger(["my-app", "validator"]).debug("Validating input", { data });}
This implicit context capability is invaluable for tracing requests through multiple layers of code without manually threading context through every function call.
When LogTape Might Not Be Your Best Choice
While LogTape offers compelling advantages for many use cases, it's not universally the best choice:
Extreme performance requirements
If your application logs tens of thousands of entries per second and raw performance is the top priority, specialized high-performance libraries like Pino may be more suitable with their focus on optimized logging throughput.
Extensive pre-built integrations
If you need immediate integration with numerous specific systems (Elasticsearch, Graylog, etc.) without writing any custom code, Winston's rich ecosystem of transports might provide a faster starting point.
Legacy systems with specific logging requirements
If you're maintaining systems built around specific logging patterns from Java or other environments, purpose-built libraries like Log4js might offer more familiar APIs.
Web browser-only applications with minimal logging needs
For extremely simple web browser-only logging needs where you just want basic console output with levels, even simpler libraries like loglevel might be sufficient.
Conclusion
LogTape stands out in the crowded JavaScript logging landscape by offering a unique combination of features that address real-world development challenges:
Zero dependencies for a lightweight, secure foundation
Runtime diversity supporting Node.js, Deno, Bun, browsers, and edge functions
Hierarchical categories for better log organization and filtering
Structured logging for improved analysis and searchability
Simple extension mechanisms with minimal boilerplate
Library-friendly design that respects separation of concerns
Whether you're building applications or libraries, working across multiple JavaScript runtimes, or simply seeking a clean, well-designed logging solution, LogTape deserves serious consideration. Its thoughtful design balances simplicity with powerful features, avoiding common pitfalls of JavaScript logging libraries.
In the diverse and ever-evolving JavaScript ecosystem, logging remains a critical component for development, debugging, and monitoring applications. While numerous logging libraries exist, LogTape stands out with its unique combination of simplicity, flexibility, and cross-runtime compatibility. Let's explore why LogTape deserves consideration for your next JavaScript or TypeScript project—whether you're building an application or a library.
Zero Dependencies: A Lightweight Footprint
One of LogTape's most compelling features is its complete absence of dependencies. In an era where “dependency hell” plagues many JavaScript projects, LogTape offers a refreshing alternative:
// No additional packages to install beyond LogTape itselfimport { configure, getConsoleSink, getLogger } from "@logtape/logtape";
This zero-dependency approach provides several advantages:
Reduced bundle size
No transitive dependencies means smaller packages
Enhanced stability
No risk of breaking changes from upstream dependencies
Simplified security
Fewer potential vulnerabilities from third-party code
Lower integration overhead
Particularly valuable for library authors who don't want to burden users with additional dependencies
Runtime Diversity: Write Once, Log Everywhere
While many popular logging libraries focus primarily on Node.js, LogTape provides seamless support across diverse JavaScript runtimes:
This runtime flexibility means you can use consistent logging patterns regardless of your deployment environment:
// Same API works seamlessly across all JavaScript runtimesimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-service", "user-management"]);// Works in Node.js, Deno, Bun, browsers, or edge functionslogger.info`User ${userId} logged in successfully`;
For teams working across multiple platforms or projects transitioning between runtimes, this consistency is invaluable. No need to learn different logging libraries or approaches—LogTape works the same way everywhere.
Hierarchical Categories: Fine-Grained Control
LogTape's hierarchical category system represents a standout feature that's surprisingly rare among JavaScript logging libraries. Categories allow you to organize logs in a tree-like structure:
This hierarchical approach offers powerful benefits:
Targeted filtering
Configure different log levels for different parts of your application
Inheritance
Child loggers inherit settings from parents, reducing configuration overhead
Organizational clarity
Logs naturally follow your application's module structure
Here's how you might configure logging levels for different categories:
await configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log"), }, loggers: [ // Base configuration for all app logs { category: ["my-app"], lowestLevel: "info", sinks: ["console", "file"] }, // More verbose logging just for database components { category: ["my-app", "database"], lowestLevel: "debug", sinks: ["file"] } ]});
With this configuration, all application logs at "info" level and above go to both console and file, while database-specific logs include more detailed "debug" level information, but only in the log file.
Structured Logging: Beyond Simple Text
Modern logging goes beyond simple text strings. LogTape embraces structured logging, which treats log entries as data objects rather than plain text:
The function is only evaluated if the debug level is enabled, preventing unnecessary computation for suppressed log levels.
Extremely Simple Sinks and Filters: Minimal Boilerplate
LogTape's approach to extensibility is remarkably straightforward. Creating custom sinks (output destinations) and filters requires minimal boilerplate code.
Dead Simple Sinks
A sink in LogTape is just a function that receives a log record:
// Creating a custom sink is as simple as defining a functionconst mySink = (record) => { const timestamp = new Date(record.timestamp).toISOString(); const level = record.level.toUpperCase(); const category = record.category.join('.'); // Send to your custom destination myCustomLogService.send({ time: timestamp, priority: level, component: category, message: record.message, ...record.properties });};// Use your custom sink in configurationawait configure({ sinks: { console: getConsoleSink(), custom: mySink }, loggers: [ { category: ["my-app"], sinks: ["console", "custom"] } ]});
Compare this with other libraries that require extending classes, implementing multiple methods, or following specific patterns. LogTape's approach is refreshingly straightforward.
Simple Filters
Similarly, filters in LogTape are just functions that return a Boolean:
// Filter that only passes high-priority or specific component logsconst importantLogsFilter = (record) => { // Always include errors if (record.level === "error" || record.level === "fatal") { return true; } // Always include payment-related logs if (record.category.includes("payments")) { return true; } // Filter out other logs return false;};await configure({ // ...sinks configuration filters: { important: importantLogsFilter }, loggers: [ { category: ["my-app"], sinks: ["alertSystem"], filters: ["important"] } ]});
LogTape also provides a convenient shorthand for level-based filtering:
await configure({ // ...sinks configuration filters: { // This creates a filter for "warning" level and above warningAndAbove: "warning" }, loggers: [ { category: ["my-app"], sinks: ["console"], filters: ["warningAndAbove"] } ]});
Perfect for Library Authors
LogTape is uniquely well-suited for library authors who want to incorporate logging without burdening their users. The core philosophy is simple:
The key point is that the library never calls configure(). Instead, it provides useful log output points with appropriate levels and contextual data.
Applications using the library can then decide exactly how to handle these logs:
// Application codeimport { configure, getConsoleSink } from "@logtape/logtape";import { Database } from "my-awesome-lib";// Configure how logs should be handledawait configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log") }, loggers: [ // Handle all library logs { category: ["my-awesome-lib"], lowestLevel: "info", sinks: ["file"] }, // More verbose for database component during development { category: ["my-awesome-lib", "database"], lowestLevel: "debug", sinks: ["console", "file"] } ]});// Use the libraryconst db = new Database("localhost", 5432, "user");db.connect();
This separation of concerns offers several benefits:
Library users have complete control over log handling
Libraries can provide rich logging without imposing implementation details
No risk of conflict with application logging configurations
Libraries can be "noisy" internally while allowing applications to filter as needed
Contexts for Richer Logging
LogTape provides context mechanisms for adding consistent properties across multiple log messages. This is particularly valuable for tracing requests through a system:
Explicit Contexts
const logger = getLogger(["my-app", "api"]);// Create a logger with contextconst requestLogger = logger.with({ requestId: "abc-123", userId: 42, endpoint: "/users"});// All logs from this logger include the context propertiesrequestLogger.info("Processing request");requestLogger.debug("Validating input");requestLogger.info("Request completed", { durationMs: 120 });
Implicit Contexts (v0.7.0+)
For cases where you want context to apply across function calls without explicit passing:
import { getLogger, withContext } from "@logtape/logtape";function handleRequest(req, res) { withContext({ requestId: req.id, userId: req.user?.id }, () => { // All logs within this function and any functions it calls // will automatically include the context properties processRequest(req, res); });}function processRequest(req, res) { // No need to pass context - it's automatically available getLogger(["my-app", "processor"]).info("Processing data"); // Call other functions that will also inherit the context validateInput(req.body);}function validateInput(data) { // This log also gets the requestId and userId getLogger(["my-app", "validator"]).debug("Validating input", { data });}
This implicit context capability is invaluable for tracing requests through multiple layers of code without manually threading context through every function call.
When LogTape Might Not Be Your Best Choice
While LogTape offers compelling advantages for many use cases, it's not universally the best choice:
Extreme performance requirements
If your application logs tens of thousands of entries per second and raw performance is the top priority, specialized high-performance libraries like Pino may be more suitable with their focus on optimized logging throughput.
Extensive pre-built integrations
If you need immediate integration with numerous specific systems (Elasticsearch, Graylog, etc.) without writing any custom code, Winston's rich ecosystem of transports might provide a faster starting point.
Legacy systems with specific logging requirements
If you're maintaining systems built around specific logging patterns from Java or other environments, purpose-built libraries like Log4js might offer more familiar APIs.
Web browser-only applications with minimal logging needs
For extremely simple web browser-only logging needs where you just want basic console output with levels, even simpler libraries like loglevel might be sufficient.
Conclusion
LogTape stands out in the crowded JavaScript logging landscape by offering a unique combination of features that address real-world development challenges:
Zero dependencies for a lightweight, secure foundation
Runtime diversity supporting Node.js, Deno, Bun, browsers, and edge functions
Hierarchical categories for better log organization and filtering
Structured logging for improved analysis and searchability
Simple extension mechanisms with minimal boilerplate
Library-friendly design that respects separation of concerns
Whether you're building applications or libraries, working across multiple JavaScript runtimes, or simply seeking a clean, well-designed logging solution, LogTape deserves serious consideration. Its thoughtful design balances simplicity with powerful features, avoiding common pitfalls of JavaScript logging libraries.
In the diverse and ever-evolving JavaScript ecosystem, logging remains a critical component for development, debugging, and monitoring applications. While numerous logging libraries exist, LogTape stands out with its unique combination of simplicity, flexibility, and cross-runtime compatibility. Let's explore why LogTape deserves consideration for your next JavaScript or TypeScript project—whether you're building an application or a library.
Zero Dependencies: A Lightweight Footprint
One of LogTape's most compelling features is its complete absence of dependencies. In an era where “dependency hell” plagues many JavaScript projects, LogTape offers a refreshing alternative:
// No additional packages to install beyond LogTape itselfimport { configure, getConsoleSink, getLogger } from "@logtape/logtape";
This zero-dependency approach provides several advantages:
Reduced bundle size
No transitive dependencies means smaller packages
Enhanced stability
No risk of breaking changes from upstream dependencies
Simplified security
Fewer potential vulnerabilities from third-party code
Lower integration overhead
Particularly valuable for library authors who don't want to burden users with additional dependencies
Runtime Diversity: Write Once, Log Everywhere
While many popular logging libraries focus primarily on Node.js, LogTape provides seamless support across diverse JavaScript runtimes:
This runtime flexibility means you can use consistent logging patterns regardless of your deployment environment:
// Same API works seamlessly across all JavaScript runtimesimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-service", "user-management"]);// Works in Node.js, Deno, Bun, browsers, or edge functionslogger.info`User ${userId} logged in successfully`;
For teams working across multiple platforms or projects transitioning between runtimes, this consistency is invaluable. No need to learn different logging libraries or approaches—LogTape works the same way everywhere.
Hierarchical Categories: Fine-Grained Control
LogTape's hierarchical category system represents a standout feature that's surprisingly rare among JavaScript logging libraries. Categories allow you to organize logs in a tree-like structure:
This hierarchical approach offers powerful benefits:
Targeted filtering
Configure different log levels for different parts of your application
Inheritance
Child loggers inherit settings from parents, reducing configuration overhead
Organizational clarity
Logs naturally follow your application's module structure
Here's how you might configure logging levels for different categories:
await configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log"), }, loggers: [ // Base configuration for all app logs { category: ["my-app"], lowestLevel: "info", sinks: ["console", "file"] }, // More verbose logging just for database components { category: ["my-app", "database"], lowestLevel: "debug", sinks: ["file"] } ]});
With this configuration, all application logs at "info" level and above go to both console and file, while database-specific logs include more detailed "debug" level information, but only in the log file.
Structured Logging: Beyond Simple Text
Modern logging goes beyond simple text strings. LogTape embraces structured logging, which treats log entries as data objects rather than plain text:
The function is only evaluated if the debug level is enabled, preventing unnecessary computation for suppressed log levels.
Extremely Simple Sinks and Filters: Minimal Boilerplate
LogTape's approach to extensibility is remarkably straightforward. Creating custom sinks (output destinations) and filters requires minimal boilerplate code.
Dead Simple Sinks
A sink in LogTape is just a function that receives a log record:
// Creating a custom sink is as simple as defining a functionconst mySink = (record) => { const timestamp = new Date(record.timestamp).toISOString(); const level = record.level.toUpperCase(); const category = record.category.join('.'); // Send to your custom destination myCustomLogService.send({ time: timestamp, priority: level, component: category, message: record.message, ...record.properties });};// Use your custom sink in configurationawait configure({ sinks: { console: getConsoleSink(), custom: mySink }, loggers: [ { category: ["my-app"], sinks: ["console", "custom"] } ]});
Compare this with other libraries that require extending classes, implementing multiple methods, or following specific patterns. LogTape's approach is refreshingly straightforward.
Simple Filters
Similarly, filters in LogTape are just functions that return a Boolean:
// Filter that only passes high-priority or specific component logsconst importantLogsFilter = (record) => { // Always include errors if (record.level === "error" || record.level === "fatal") { return true; } // Always include payment-related logs if (record.category.includes("payments")) { return true; } // Filter out other logs return false;};await configure({ // ...sinks configuration filters: { important: importantLogsFilter }, loggers: [ { category: ["my-app"], sinks: ["alertSystem"], filters: ["important"] } ]});
LogTape also provides a convenient shorthand for level-based filtering:
await configure({ // ...sinks configuration filters: { // This creates a filter for "warning" level and above warningAndAbove: "warning" }, loggers: [ { category: ["my-app"], sinks: ["console"], filters: ["warningAndAbove"] } ]});
Perfect for Library Authors
LogTape is uniquely well-suited for library authors who want to incorporate logging without burdening their users. The core philosophy is simple:
The key point is that the library never calls configure(). Instead, it provides useful log output points with appropriate levels and contextual data.
Applications using the library can then decide exactly how to handle these logs:
// Application codeimport { configure, getConsoleSink } from "@logtape/logtape";import { Database } from "my-awesome-lib";// Configure how logs should be handledawait configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log") }, loggers: [ // Handle all library logs { category: ["my-awesome-lib"], lowestLevel: "info", sinks: ["file"] }, // More verbose for database component during development { category: ["my-awesome-lib", "database"], lowestLevel: "debug", sinks: ["console", "file"] } ]});// Use the libraryconst db = new Database("localhost", 5432, "user");db.connect();
This separation of concerns offers several benefits:
Library users have complete control over log handling
Libraries can provide rich logging without imposing implementation details
No risk of conflict with application logging configurations
Libraries can be "noisy" internally while allowing applications to filter as needed
Contexts for Richer Logging
LogTape provides context mechanisms for adding consistent properties across multiple log messages. This is particularly valuable for tracing requests through a system:
Explicit Contexts
const logger = getLogger(["my-app", "api"]);// Create a logger with contextconst requestLogger = logger.with({ requestId: "abc-123", userId: 42, endpoint: "/users"});// All logs from this logger include the context propertiesrequestLogger.info("Processing request");requestLogger.debug("Validating input");requestLogger.info("Request completed", { durationMs: 120 });
Implicit Contexts (v0.7.0+)
For cases where you want context to apply across function calls without explicit passing:
import { getLogger, withContext } from "@logtape/logtape";function handleRequest(req, res) { withContext({ requestId: req.id, userId: req.user?.id }, () => { // All logs within this function and any functions it calls // will automatically include the context properties processRequest(req, res); });}function processRequest(req, res) { // No need to pass context - it's automatically available getLogger(["my-app", "processor"]).info("Processing data"); // Call other functions that will also inherit the context validateInput(req.body);}function validateInput(data) { // This log also gets the requestId and userId getLogger(["my-app", "validator"]).debug("Validating input", { data });}
This implicit context capability is invaluable for tracing requests through multiple layers of code without manually threading context through every function call.
When LogTape Might Not Be Your Best Choice
While LogTape offers compelling advantages for many use cases, it's not universally the best choice:
Extreme performance requirements
If your application logs tens of thousands of entries per second and raw performance is the top priority, specialized high-performance libraries like Pino may be more suitable with their focus on optimized logging throughput.
Extensive pre-built integrations
If you need immediate integration with numerous specific systems (Elasticsearch, Graylog, etc.) without writing any custom code, Winston's rich ecosystem of transports might provide a faster starting point.
Legacy systems with specific logging requirements
If you're maintaining systems built around specific logging patterns from Java or other environments, purpose-built libraries like Log4js might offer more familiar APIs.
Web browser-only applications with minimal logging needs
For extremely simple web browser-only logging needs where you just want basic console output with levels, even simpler libraries like loglevel might be sufficient.
Conclusion
LogTape stands out in the crowded JavaScript logging landscape by offering a unique combination of features that address real-world development challenges:
Zero dependencies for a lightweight, secure foundation
Runtime diversity supporting Node.js, Deno, Bun, browsers, and edge functions
Hierarchical categories for better log organization and filtering
Structured logging for improved analysis and searchability
Simple extension mechanisms with minimal boilerplate
Library-friendly design that respects separation of concerns
Whether you're building applications or libraries, working across multiple JavaScript runtimes, or simply seeking a clean, well-designed logging solution, LogTape deserves serious consideration. Its thoughtful design balances simplicity with powerful features, avoiding common pitfalls of JavaScript logging libraries.
In the diverse and ever-evolving JavaScript ecosystem, logging remains a critical component for development, debugging, and monitoring applications. While numerous logging libraries exist, LogTape stands out with its unique combination of simplicity, flexibility, and cross-runtime compatibility. Let's explore why LogTape deserves consideration for your next JavaScript or TypeScript project—whether you're building an application or a library.
Zero Dependencies: A Lightweight Footprint
One of LogTape's most compelling features is its complete absence of dependencies. In an era where “dependency hell” plagues many JavaScript projects, LogTape offers a refreshing alternative:
// No additional packages to install beyond LogTape itselfimport { configure, getConsoleSink, getLogger } from "@logtape/logtape";
This zero-dependency approach provides several advantages:
Reduced bundle size
No transitive dependencies means smaller packages
Enhanced stability
No risk of breaking changes from upstream dependencies
Simplified security
Fewer potential vulnerabilities from third-party code
Lower integration overhead
Particularly valuable for library authors who don't want to burden users with additional dependencies
Runtime Diversity: Write Once, Log Everywhere
While many popular logging libraries focus primarily on Node.js, LogTape provides seamless support across diverse JavaScript runtimes:
This runtime flexibility means you can use consistent logging patterns regardless of your deployment environment:
// Same API works seamlessly across all JavaScript runtimesimport { getLogger } from "@logtape/logtape";const logger = getLogger(["my-service", "user-management"]);// Works in Node.js, Deno, Bun, browsers, or edge functionslogger.info`User ${userId} logged in successfully`;
For teams working across multiple platforms or projects transitioning between runtimes, this consistency is invaluable. No need to learn different logging libraries or approaches—LogTape works the same way everywhere.
Hierarchical Categories: Fine-Grained Control
LogTape's hierarchical category system represents a standout feature that's surprisingly rare among JavaScript logging libraries. Categories allow you to organize logs in a tree-like structure:
This hierarchical approach offers powerful benefits:
Targeted filtering
Configure different log levels for different parts of your application
Inheritance
Child loggers inherit settings from parents, reducing configuration overhead
Organizational clarity
Logs naturally follow your application's module structure
Here's how you might configure logging levels for different categories:
await configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log"), }, loggers: [ // Base configuration for all app logs { category: ["my-app"], lowestLevel: "info", sinks: ["console", "file"] }, // More verbose logging just for database components { category: ["my-app", "database"], lowestLevel: "debug", sinks: ["file"] } ]});
With this configuration, all application logs at "info" level and above go to both console and file, while database-specific logs include more detailed "debug" level information, but only in the log file.
Structured Logging: Beyond Simple Text
Modern logging goes beyond simple text strings. LogTape embraces structured logging, which treats log entries as data objects rather than plain text:
The function is only evaluated if the debug level is enabled, preventing unnecessary computation for suppressed log levels.
Extremely Simple Sinks and Filters: Minimal Boilerplate
LogTape's approach to extensibility is remarkably straightforward. Creating custom sinks (output destinations) and filters requires minimal boilerplate code.
Dead Simple Sinks
A sink in LogTape is just a function that receives a log record:
// Creating a custom sink is as simple as defining a functionconst mySink = (record) => { const timestamp = new Date(record.timestamp).toISOString(); const level = record.level.toUpperCase(); const category = record.category.join('.'); // Send to your custom destination myCustomLogService.send({ time: timestamp, priority: level, component: category, message: record.message, ...record.properties });};// Use your custom sink in configurationawait configure({ sinks: { console: getConsoleSink(), custom: mySink }, loggers: [ { category: ["my-app"], sinks: ["console", "custom"] } ]});
Compare this with other libraries that require extending classes, implementing multiple methods, or following specific patterns. LogTape's approach is refreshingly straightforward.
Simple Filters
Similarly, filters in LogTape are just functions that return a Boolean:
// Filter that only passes high-priority or specific component logsconst importantLogsFilter = (record) => { // Always include errors if (record.level === "error" || record.level === "fatal") { return true; } // Always include payment-related logs if (record.category.includes("payments")) { return true; } // Filter out other logs return false;};await configure({ // ...sinks configuration filters: { important: importantLogsFilter }, loggers: [ { category: ["my-app"], sinks: ["alertSystem"], filters: ["important"] } ]});
LogTape also provides a convenient shorthand for level-based filtering:
await configure({ // ...sinks configuration filters: { // This creates a filter for "warning" level and above warningAndAbove: "warning" }, loggers: [ { category: ["my-app"], sinks: ["console"], filters: ["warningAndAbove"] } ]});
Perfect for Library Authors
LogTape is uniquely well-suited for library authors who want to incorporate logging without burdening their users. The core philosophy is simple:
The key point is that the library never calls configure(). Instead, it provides useful log output points with appropriate levels and contextual data.
Applications using the library can then decide exactly how to handle these logs:
// Application codeimport { configure, getConsoleSink } from "@logtape/logtape";import { Database } from "my-awesome-lib";// Configure how logs should be handledawait configure({ sinks: { console: getConsoleSink(), file: getFileSink("app.log") }, loggers: [ // Handle all library logs { category: ["my-awesome-lib"], lowestLevel: "info", sinks: ["file"] }, // More verbose for database component during development { category: ["my-awesome-lib", "database"], lowestLevel: "debug", sinks: ["console", "file"] } ]});// Use the libraryconst db = new Database("localhost", 5432, "user");db.connect();
This separation of concerns offers several benefits:
Library users have complete control over log handling
Libraries can provide rich logging without imposing implementation details
No risk of conflict with application logging configurations
Libraries can be "noisy" internally while allowing applications to filter as needed
Contexts for Richer Logging
LogTape provides context mechanisms for adding consistent properties across multiple log messages. This is particularly valuable for tracing requests through a system:
Explicit Contexts
const logger = getLogger(["my-app", "api"]);// Create a logger with contextconst requestLogger = logger.with({ requestId: "abc-123", userId: 42, endpoint: "/users"});// All logs from this logger include the context propertiesrequestLogger.info("Processing request");requestLogger.debug("Validating input");requestLogger.info("Request completed", { durationMs: 120 });
Implicit Contexts (v0.7.0+)
For cases where you want context to apply across function calls without explicit passing:
import { getLogger, withContext } from "@logtape/logtape";function handleRequest(req, res) { withContext({ requestId: req.id, userId: req.user?.id }, () => { // All logs within this function and any functions it calls // will automatically include the context properties processRequest(req, res); });}function processRequest(req, res) { // No need to pass context - it's automatically available getLogger(["my-app", "processor"]).info("Processing data"); // Call other functions that will also inherit the context validateInput(req.body);}function validateInput(data) { // This log also gets the requestId and userId getLogger(["my-app", "validator"]).debug("Validating input", { data });}
This implicit context capability is invaluable for tracing requests through multiple layers of code without manually threading context through every function call.
When LogTape Might Not Be Your Best Choice
While LogTape offers compelling advantages for many use cases, it's not universally the best choice:
Extreme performance requirements
If your application logs tens of thousands of entries per second and raw performance is the top priority, specialized high-performance libraries like Pino may be more suitable with their focus on optimized logging throughput.
Extensive pre-built integrations
If you need immediate integration with numerous specific systems (Elasticsearch, Graylog, etc.) without writing any custom code, Winston's rich ecosystem of transports might provide a faster starting point.
Legacy systems with specific logging requirements
If you're maintaining systems built around specific logging patterns from Java or other environments, purpose-built libraries like Log4js might offer more familiar APIs.
Web browser-only applications with minimal logging needs
For extremely simple web browser-only logging needs where you just want basic console output with levels, even simpler libraries like loglevel might be sufficient.
Conclusion
LogTape stands out in the crowded JavaScript logging landscape by offering a unique combination of features that address real-world development challenges:
Zero dependencies for a lightweight, secure foundation
Runtime diversity supporting Node.js, Deno, Bun, browsers, and edge functions
Hierarchical categories for better log organization and filtering
Structured logging for improved analysis and searchability
Simple extension mechanisms with minimal boilerplate
Library-friendly design that respects separation of concerns
Whether you're building applications or libraries, working across multiple JavaScript runtimes, or simply seeking a clean, well-designed logging solution, LogTape deserves serious consideration. Its thoughtful design balances simplicity with powerful features, avoiding common pitfalls of JavaScript logging libraries.
Okay, yeah, so, that method was BS for two reasons: I'm formatting the milliseconds from the log record, but the rest of the timestamp from "now" (lol, ouch) – but also, the underlying problem is using time.strftime (like the base class) instead of the more modern datetime.datetime.strftime. Because the latter actually _does_ have a format string placeholder for microseconds (not milliseconds though).
So, after a bit of iteration, I think I'll be going with this one:
ALT text detailsThe class now sets its format string in a class attribute "default_time_format" just like the base class does. It's also using datetime.datetime.fromtimestamp() to convert record.created (a float) into a (naive) datetime object, and then calls .astimezone() without arguments to convert it into an aware datetime for the local timezone. After that, it's just a call to strftime with either the datefmt string passed to the method or the class-level default as its format string.
Code follows:
class ISOTimeFormatter(logging.Formatter):
default_time_format = "%Y-%m-%d %H:%M:%S.%f%z"
def formatTime(
self, record: logging.LogRecord, datefmt: str | None = None
) -> str:
return (
datetime.fromtimestamp(record.created)
.astimezone() # convert to aware object using local timezone
.strftime(datefmt or self.default_time_format)
)
I’ve been logging everything I do in a personal CHANGELOG.md in @obsidian since January, and I absolutely love it.
Every day I add something to the list, and it makes me feel like I'm achieving something. This is an important part of recovering from feelings of inadequacy and workaholic tendencies.
ALT text detailsLife changelog
> [!NOTE] Please note
> Remember the same constants, like days alive, inboxzero, run kms, financial meetings, etc. These are easily missed from day to day updates.
### 1.8.7: 2025-04-18
* Day 13317 alive
* InboxZero
* A bit of work, checking Slack, emails, etc... (yeah, yeah, I know it's Easter day, Good Friday or something and should not be working)
* Low recovery, so rest day today
* Go to movies with the whole family to watch Minecraft
* Install obsidian-share-as-gist and obsidian-imgur-plugin, Closes FUN-6
* Move Sunsama backlog to Linear, Closes FUN-10
### 1.8.6: 2025-04-17
* Day 13316 alive
* InboxZero
* Hard stop *before* 6pm successful 🔥 **9-day streak**
* Quick YNAB
ALT text detailsA Python class ISOTimeFormatter (extending logging.Formatter) that uses an f-string to inject record.msecs into the format string passed to time.strftime. Code follows:
class ISOTimeFormatter(logging.Formatter):
@staticmethod
def formatTime(
record: logging.LogRecord, datefmt: str | None = None
) -> str:
return time.strftime(f"%Y-%m-%d %H:%M:%S.{record.msecs:03.0f}%z")
This version brings two major improvements to our zero-dependency #logging library for #TypeScript:
New Synchronous Configuration API: You can now configure LogTape synchronously with configureSync(), disposeSync(), and resetSync(). Perfect for simpler setups where you don't need async operations!
Better Runtime Compatibility: We've moved all file-related components to a separate @logtape/file package. This means the core package now works flawlessly across all JavaScript environments—browsers, edge functions, and various bundlers without any file system dependencies.
Plus, we've added level mapping options for console sinks, giving you more control over how your logs appear.
Check out the full release notes for migration details:
We're excited to announce the release of LogTape 0.9.0! This version brings important improvements to make LogTape more flexible across different JavaScript environments while simplifying configuration for common use cases.
What's New
Synchronous Configuration API: Added new synchronous configuration functions for environments where async operations aren't needed or desired
Improved Runtime Compatibility: Moved file-system dependent components to a separate package for better cross-runtime support
New Features
Synchronous Configuration API: Simplifying Your Setup
Added synchronous versions of the configuration functions:
These functions offer a simpler API for scenarios where async operations aren't needed, allowing for more straightforward code without awaiting promises. Note that these functions cannot use sinks or filters that require asynchronous disposal (such as stream sinks), but they work perfectly for most common logging configurations.
This architectural change ensures the core @logtape/logtape package is fully compatible with all JavaScript runtimes, including browsers and edge functions, without introducing file system dependencies. You'll now enjoy better compatibility with bundlers like Webpack, Rollup, and Vite that previously had issues with the file system imports.
Migration Guide
If you were using file sinks, update your imports:
// Beforeimport { getFileSink, getRotatingFileSink } from "@logtape/logtape";// Afterimport { getFileSink, getRotatingFileSink } from "@logtape/file";
Don't forget to install the new package:
# For npm, pnpm, Yarn, Bunnpm add @logtape/file# For Denodeno add jsr:@logtape/file
Looking Forward
This release represents our ongoing commitment to making LogTape the most flexible and developer-friendly logging solution for JavaScript and TypeScript applications. We're continuing to improve performance and extend compatibility across the JavaScript ecosystem.
Contributors
Special thanks to Murph Murphy for their valuable contribution to this release.
As always, we welcome your feedback and contributions! Feel free to open issues or pull requests on our GitHub repository.
This version brings two major improvements to our zero-dependency #logging library for #TypeScript:
New Synchronous Configuration API: You can now configure LogTape synchronously with configureSync(), disposeSync(), and resetSync(). Perfect for simpler setups where you don't need async operations!
Better Runtime Compatibility: We've moved all file-related components to a separate @logtape/file package. This means the core package now works flawlessly across all JavaScript environments—browsers, edge functions, and various bundlers without any file system dependencies.
Plus, we've added level mapping options for console sinks, giving you more control over how your logs appear.
Check out the full release notes for migration details:
We're excited to announce the release of LogTape 0.9.0! This version brings important improvements to make LogTape more flexible across different JavaScript environments while simplifying configuration for common use cases.
What's New
Synchronous Configuration API: Added new synchronous configuration functions for environments where async operations aren't needed or desired
Improved Runtime Compatibility: Moved file-system dependent components to a separate package for better cross-runtime support
New Features
Synchronous Configuration API: Simplifying Your Setup
Added synchronous versions of the configuration functions:
These functions offer a simpler API for scenarios where async operations aren't needed, allowing for more straightforward code without awaiting promises. Note that these functions cannot use sinks or filters that require asynchronous disposal (such as stream sinks), but they work perfectly for most common logging configurations.
This architectural change ensures the core @logtape/logtape package is fully compatible with all JavaScript runtimes, including browsers and edge functions, without introducing file system dependencies. You'll now enjoy better compatibility with bundlers like Webpack, Rollup, and Vite that previously had issues with the file system imports.
Migration Guide
If you were using file sinks, update your imports:
// Beforeimport { getFileSink, getRotatingFileSink } from "@logtape/logtape";// Afterimport { getFileSink, getRotatingFileSink } from "@logtape/file";
Don't forget to install the new package:
# For npm, pnpm, Yarn, Bunnpm add @logtape/file# For Denodeno add jsr:@logtape/file
Looking Forward
This release represents our ongoing commitment to making LogTape the most flexible and developer-friendly logging solution for JavaScript and TypeScript applications. We're continuing to improve performance and extend compatibility across the JavaScript ecosystem.
Contributors
Special thanks to Murph Murphy for their valuable contribution to this release.
As always, we welcome your feedback and contributions! Feel free to open issues or pull requests on our GitHub repository.
This version brings two major improvements to our zero-dependency #logging library for #TypeScript:
New Synchronous Configuration API: You can now configure LogTape synchronously with configureSync(), disposeSync(), and resetSync(). Perfect for simpler setups where you don't need async operations!
Better Runtime Compatibility: We've moved all file-related components to a separate @logtape/file package. This means the core package now works flawlessly across all JavaScript environments—browsers, edge functions, and various bundlers without any file system dependencies.
Plus, we've added level mapping options for console sinks, giving you more control over how your logs appear.
Check out the full release notes for migration details:
We're excited to announce the release of LogTape 0.9.0! This version brings important improvements to make LogTape more flexible across different JavaScript environments while simplifying configuration for common use cases.
What's New
Synchronous Configuration API: Added new synchronous configuration functions for environments where async operations aren't needed or desired
Improved Runtime Compatibility: Moved file-system dependent components to a separate package for better cross-runtime support
New Features
Synchronous Configuration API: Simplifying Your Setup
Added synchronous versions of the configuration functions:
These functions offer a simpler API for scenarios where async operations aren't needed, allowing for more straightforward code without awaiting promises. Note that these functions cannot use sinks or filters that require asynchronous disposal (such as stream sinks), but they work perfectly for most common logging configurations.
This architectural change ensures the core @logtape/logtape package is fully compatible with all JavaScript runtimes, including browsers and edge functions, without introducing file system dependencies. You'll now enjoy better compatibility with bundlers like Webpack, Rollup, and Vite that previously had issues with the file system imports.
Migration Guide
If you were using file sinks, update your imports:
// Beforeimport { getFileSink, getRotatingFileSink } from "@logtape/logtape";// Afterimport { getFileSink, getRotatingFileSink } from "@logtape/file";
Don't forget to install the new package:
# For npm, pnpm, Yarn, Bunnpm add @logtape/file# For Denodeno add jsr:@logtape/file
Looking Forward
This release represents our ongoing commitment to making LogTape the most flexible and developer-friendly logging solution for JavaScript and TypeScript applications. We're continuing to improve performance and extend compatibility across the JavaScript ecosystem.
Contributors
Special thanks to Murph Murphy for their valuable contribution to this release.
As always, we welcome your feedback and contributions! Feel free to open issues or pull requests on our GitHub repository.
This version brings two major improvements to our zero-dependency #logging library for #TypeScript:
New Synchronous Configuration API: You can now configure LogTape synchronously with configureSync(), disposeSync(), and resetSync(). Perfect for simpler setups where you don't need async operations!
Better Runtime Compatibility: We've moved all file-related components to a separate @logtape/file package. This means the core package now works flawlessly across all JavaScript environments—browsers, edge functions, and various bundlers without any file system dependencies.
Plus, we've added level mapping options for console sinks, giving you more control over how your logs appear.
Check out the full release notes for migration details:
We're excited to announce the release of LogTape 0.9.0! This version brings important improvements to make LogTape more flexible across different JavaScript environments while simplifying configuration for common use cases.
What's New
Synchronous Configuration API: Added new synchronous configuration functions for environments where async operations aren't needed or desired
Improved Runtime Compatibility: Moved file-system dependent components to a separate package for better cross-runtime support
New Features
Synchronous Configuration API: Simplifying Your Setup
Added synchronous versions of the configuration functions:
These functions offer a simpler API for scenarios where async operations aren't needed, allowing for more straightforward code without awaiting promises. Note that these functions cannot use sinks or filters that require asynchronous disposal (such as stream sinks), but they work perfectly for most common logging configurations.
This architectural change ensures the core @logtape/logtape package is fully compatible with all JavaScript runtimes, including browsers and edge functions, without introducing file system dependencies. You'll now enjoy better compatibility with bundlers like Webpack, Rollup, and Vite that previously had issues with the file system imports.
Migration Guide
If you were using file sinks, update your imports:
// Beforeimport { getFileSink, getRotatingFileSink } from "@logtape/logtape";// Afterimport { getFileSink, getRotatingFileSink } from "@logtape/file";
Don't forget to install the new package:
# For npm, pnpm, Yarn, Bunnpm add @logtape/file# For Denodeno add jsr:@logtape/file
Looking Forward
This release represents our ongoing commitment to making LogTape the most flexible and developer-friendly logging solution for JavaScript and TypeScript applications. We're continuing to improve performance and extend compatibility across the JavaScript ecosystem.
Contributors
Special thanks to Murph Murphy for their valuable contribution to this release.
As always, we welcome your feedback and contributions! Feel free to open issues or pull requests on our GitHub repository.
Haven't talked about LogTape in a while—it's a #logging library I made for #JavaScript and #TypeScript. You know how logging can be a pain point in JavaScript/TypeScript development? Well, I tried to address some common frustrations.
What makes it special
Zero dependencies
We've all been there with dependency hell, right? #LogTape has absolutely no external dependencies. Install it without worrying about bloating your node_modules.
You can organize your logs in a tree structure. Want to save only database-related logs to a file? Easy to do. Child categories can inherit settings from their parents too, which keeps things clean and manageable.
Writing a library and want to include logs without stepping on your users' toes? LogTape lets you add logging to your library while giving end users complete control over how those logs are handled.
Haven't talked about LogTape in a while—it's a #logging library I made for #JavaScript and #TypeScript. You know how logging can be a pain point in JavaScript/TypeScript development? Well, I tried to address some common frustrations.
What makes it special
Zero dependencies
We've all been there with dependency hell, right? #LogTape has absolutely no external dependencies. Install it without worrying about bloating your node_modules.
You can organize your logs in a tree structure. Want to save only database-related logs to a file? Easy to do. Child categories can inherit settings from their parents too, which keeps things clean and manageable.
Writing a library and want to include logs without stepping on your users' toes? LogTape lets you add logging to your library while giving end users complete control over how those logs are handled.
Haven't talked about LogTape in a while—it's a #logging library I made for #JavaScript and #TypeScript. You know how logging can be a pain point in JavaScript/TypeScript development? Well, I tried to address some common frustrations.
What makes it special
Zero dependencies
We've all been there with dependency hell, right? #LogTape has absolutely no external dependencies. Install it without worrying about bloating your node_modules.
You can organize your logs in a tree structure. Want to save only database-related logs to a file? Easy to do. Child categories can inherit settings from their parents too, which keeps things clean and manageable.
Writing a library and want to include logs without stepping on your users' toes? LogTape lets you add logging to your library while giving end users complete control over how those logs are handled.
Haven't talked about LogTape in a while—it's a #logging library I made for #JavaScript and #TypeScript. You know how logging can be a pain point in JavaScript/TypeScript development? Well, I tried to address some common frustrations.
What makes it special
Zero dependencies
We've all been there with dependency hell, right? #LogTape has absolutely no external dependencies. Install it without worrying about bloating your node_modules.
You can organize your logs in a tree structure. Want to save only database-related logs to a file? Easy to do. Child categories can inherit settings from their parents too, which keeps things clean and manageable.
Writing a library and want to include logs without stepping on your users' toes? LogTape lets you add logging to your library while giving end users complete control over how those logs are handled.
Haven't talked about LogTape in a while—it's a #logging library I made for #JavaScript and #TypeScript. You know how logging can be a pain point in JavaScript/TypeScript development? Well, I tried to address some common frustrations.
What makes it special
Zero dependencies
We've all been there with dependency hell, right? #LogTape has absolutely no external dependencies. Install it without worrying about bloating your node_modules.
You can organize your logs in a tree structure. Want to save only database-related logs to a file? Easy to do. Child categories can inherit settings from their parents too, which keeps things clean and manageable.
Writing a library and want to include logs without stepping on your users' toes? LogTape lets you add logging to your library while giving end users complete control over how those logs are handled.
Dearest Fediverse (and apologies for the absence),
my book "Hard Work: Producing places, relations and value on a Papua New Guinea resource frontier" was just recently published in full digital open access. (Print-on-demand and oa epub out soon!)
"Hard Work explores the complexities of natural resource extraction, looking at both large-scale processes and personal human-environment interactions. It combines a political ecology focus on the connection between environmental issues and power relations with a focus on how value is produced, represented, and materialized."
ALT text detailsCover of the book "Hard Work". The cover is a photograph showing a foggy tropical river valley. On the foreground on the left stands a Papua New Guinean woman with her back to the camera holding a food basket on her head and walking staff in her right hand looking at the valley. The woman stands in tropical garden and in front of her are banana plants. On right, a bit further from the camera is a tall tree standing in the garden. In the background are forested mountain slopes.
On the top of the cover is the name of the author, "Tuomas Tammisto". Below it is the title of the book: "Hard Work: Producing places, relations and value on a Papua New Guinea resource frontier". On the bottom left is the name of the publisher: "HUP Helsinki University Press".
Just released #LogTape 0.7.0 with implicit contexts! Now you can automatically include request IDs, user IDs, and more in your logs without passing context manually. Read more about this powerful feature:
Activists shared a win with the #Kananaskis logging slowdown last year, temporarily saving 2000 football fields worth of climate-preserving forest & trails but for how long & what comes next? We asked the Hub's Jenny Yeremiy & Joshua Killeen of #CPAWS.
ALT text details2 images, 1 image is podcast episode cover reads "Kananaskis Clearcuts: Outdated Laws, New Threats," includes 'the Climate Lens' and Calgary Climate Hub logos and a banner reads "NEW EPISODE OUT NOW!"
Image 2 is a map of Kanaaskis Country with a red circle around the Highwood area
ALT text details2 images, 1 image is podcast episode cover reads "Kananaskis Clearcuts: Outdated Laws, New Threats," includes 'the Climate Lens' and Calgary Climate Hub logos and a banner reads "NEW EPISODE OUT NOW!"
Image 2 is a map of Kanaaskis Country with a red circle around the Highwood area
ALT text details2 images, 1 image is podcast episode cover reads "Kananaskis Clearcuts: Outdated Laws, New Threats," includes 'the Climate Lens' and Calgary Climate Hub logos and a banner reads "NEW EPISODE OUT NOW!"
Image 2 is a map of Kanaaskis Country with a red circle around the Highwood area
Version 0.5.0 of #LogTape, the zero-dependency #logging library for #Deno, #Node.js, #Bun, edge functions, and browsers, has been released! The main additions include:
• Contexts • ANSI color formatter • Comprehensive docs • A few API conveniences
In the next version of #LogTape, a zero-dependency #logging library for #JavaScript & #TypeScript, contexts will be introduced that allow the same set of properties to be shared across multiple log messages. Thanks to @okikio for collaborating on the design! This feature is available for preview in 0.5.0-dev.60+f819929c.
ALT text detailsconst logger = getLogger(["my-app", "my-module"]);
const ctx = logger.with({ userId: 1234, requestId: "abc" });
ctx.info `This log message will have the context (userId & requestId).`;
ctx.warn("Context can be used inside message template: {userId}, {requestId}.");
Fedify uses hierarchical categories for fine-grained control over log output. Key categories include ["fedify", "federation", "http"] for HTTP requests/responses and ["fedify", "federation", "inbox"]/["fedify", "federation", "outbox"] for incoming/outgoing activities. (There are more categories.)
With #LogTape integration, you gain valuable insights into your Fedify app's behavior, making troubleshooting and optimization much more straightforward!
I've been enjoying infosec.exchange for the last month or so but have been putting off an #Introduction because I'm awkward and anxious (#privacy am I right?). I feel more comfortable talking about my cat than myself or my work on social media, so you'll probably mostly see him amongst my boosts and replies. He's a little hacker who tricks me into FaceID unlocking my iPad for him or hides my pouch of physical security keys to remind me not to be careless with them.
See how I just went on about the cat? Yeah... I feel imposter syndrome about belonging in #InfoSec. I'm an IT #security and #operations focused #SysAdmin (#BlueTeam) whose been fascinated/working with computers since I was 3, and have been doing it professionally for over 10 years now. Does that make me #SecOps? I honestly don't know. I love this community though and want to make an effort to share what I do know more often besides the cat pics or conversations or boosting #ThreatIntel and news I think to share.
![Life changelog
> [!NOTE] Please note
> Remember the same constants, like days alive, inboxzero, run kms, financial meetings, etc. These are easily missed from day to day updates.
### 1.8.7: 2025-04-18
* Day 13317 alive
* InboxZero
* A bit of work, checking Slack, emails, etc... (yeah, yeah, I know it's Easter day, Good Friday or something and should not be working)
* Low recovery, so rest day today
* Go to movies with the whole family to watch Minecraft
* Install obsidian-share-as-gist and obsidian-imgur-plugin, Closes FUN-6
* Move Sunsama backlog to Linear, Closes FUN-10
### 1.8.6: 2025-04-17
* Day 13316 alive
* InboxZero
* Hard stop *before* 6pm successful 🔥 **9-day streak**
* Quick YNAB](https://media.mementomori.social/media_attachments/files/114/359/159/804/935/046/original/1a6891fe72757afa.png)
![const logger = getLogger(["my-app", "my-module"]);
const ctx = logger.with({ userId: 1234, requestId: "abc" });
ctx.info `This log message will have the context (userId & requestId).`;
ctx.warn("Context can be used inside message template: {userId}, {requestId}.");](https://cdn.fosstodon.org/media_attachments/files/112/993/768/450/365/884/original/c80e0755b3ee5aa9.png)
