LogLayer

What's new in LogLayer ​

July 10, 2025 ​

loglayer:

  • Added the new Blank Transport that allows you to quickly create custom transports by providing your own shipToLogger function. This is perfect for simple custom logging logic, prototyping new transport ideas, or quick integrations with custom services.
  • The built-in Console Transport has new options to stamp out a timestamp and/or a log level with your log.

June 30, 2025 ​

  • @loglayer/transport-simple-pretty-terminal: Fixes a bug where in expanded mode, empty lines were being printed when no metadata is being used with a log entry

June 23, 2025 ​

Updated Simple Pretty Terminal:

  • In the browser runtime mode, we were printing all logs using console.log(). This behavior has changed to use the appropriate console method depending on log level, and should now allow proper filtering from a browser's devtools when filtering by level.
  • Removed algorithmic word-wrapping in the terminal view, which looks awkward when using tools like turbo concurrently with other apps. The user's terminal should handle wrapping instead.
  • Added a new option includeDataInBrowserConsole, which will add the raw data object to the console print (eg console.info(message, data)), allowing for deep inspection from the devtools.

June 22, 2025 ​

Added a new Hono integration guide.

June 21, 2025 ​

Added the new Simple Pretty Terminal that is designed for Next.js, browsers and apps that run concurrently.

Simple View

Updated the Next.js integration guide to incorporate the Simple Pretty Transport.

June 19, 2025 ​

  • (all packages) Dev dependency package updates

Added the new HTTP Transport for LogLayer that allows you to send logs to any HTTP endpoint.

HTTP Transport Features ​

  • 🌐 Generic HTTP Support - Send logs to any HTTP endpoint with configurable method and headers
  • 📦 Custom Payload Templates - Transform log data into any format your API expects
  • 🔄 Batching Support - Queue logs and send them in batches for better performance
  • 🗜️ Gzip Compression - Reduce bandwidth usage with optional compression
  • 🔁 Retry Logic - Automatic retries with exponential backoff
  • ⏱️ Rate Limiting - Respect HTTP 429 responses with configurable behavior
  • 🎯 Dynamic Headers - Use functions to generate headers dynamically
  • 🐛 Error Handling - Comprehensive error callbacks for debugging and monitoring

Added the new VictoriaLogs Transport for LogLayer that allows you to send logs to VictoriaLogs using the JSON stream API.

VictoriaLogs Transport Features ​

  • 🚀 VictoriaLogs Integration - Send logs to VictoriaLogs using the JSON stream API
  • 🔧 Pre-configured Setup - Thin wrapper around HTTP transport with VictoriaLogs specific defaults
  • 📝 Automatic URL Construction - Automatically appends /insert/jsonline path to your VictoriaLogs host URL
  • 🎯 VictoriaLogs Format - Pre-configured payload template with _msg, _time, level, stream, service, and environment fields
  • 🔄 Full HTTP Transport Features - Inherits all features from HTTP transport (batching, compression, retries, etc.)
  • ⚡ High Performance - Supports unlimited log lines in a single request with stream-based processing

May 24, 2025 ​

For loglayer:

Adds the following type exports for assistance with writing plugins directly:

  • PluginBeforeDataOutParams,
  • PluginBeforeMessageOutParams,
  • PluginShouldSendToLoggerParams

May 23, 2025 ​

For loglayer:

Fixes a potential issue where you can't import from loglayer due to the package exporting the LogLevel enum from different LogLayer core packages.

May 10, 2025 ​

It is advised that if you update loglayer, you should update any plugins and transports to the latest versions as well.

  • Added the following new methods to control log levels in loglayer:
    • setLevel()
    • enableIndividualLevel()
    • disableIndividualLevel()
    • isLevelEnabled()

See the documentation for more information.

  • Fixes a bug in metadataOnly() where it was sometimes returning the LogLayer instance instead of nothing. It should now return nothing.
  • Source maps have been disabled to save on package file size. If this is an issue please raise one!

For loglayer, plugins, and transports:

  • Adds a new TypeScript type called LogLevelType, which is a union of the LogLevel enum and its string representation.
    • This means you can use either LogLevel.info or just info (string)
    • All usages of LogLevel as a parameter type have been replaced with LogLevelType.
  • Some packages have source maps disabled to save on package file size. If this is an issue please raise one!

Apr 12, 2025 ​

Adds support for the llms.txt format.

Mar 29, 2025 ​

General dev-only package updates.

loglayer:

  • Fixed a bug in MockLogLayer where child() and withPrefix() should be returning itself instead of a MockLogBuilder

Mar 16, 2025 ​

Documentation:

loglayer:

  • Added an export for the LogLayerTransport type.

Mar 5, 2025 ​

Documentation updates.

  • Added new comments and links for interfaces, types, and classes.
  • Added that booleans can be used in a logging method (eg log.info("value:", true)) despite saying only strings and numbers only

In @loglayer/transport-opentelemetry:

  • Internal: Removed LogLayer version imprinting. This shouldn't affect behavior, but please raise an issue if it does.

Mar 3, 2025 ​

In loglayer:

Updates to the MockLogLayer behavior to help with writing unit tests specifically against the logger:

  • MockLogLayer now creates an internal instance of MockLogBuilder when created. This is changed from the prior behavior of creating a new instance of MockLogBuilder for certain method calls that would return it like withMetadata.
  • Added getMockLogBuilder(), resetMockLogBuilder(), and setMockLogBuilder() methods to MockLogLayer to allow developers to write direct mocks against chained methods like withMetadata, withError, etc.

The testing documentation for this has been updated as well.

Mar 1, 2025 ​

  • All transports now support multiple parameter passing in log methods. For example, log.info('User', 123, 'logged in').
    • The logging library for the transport may not support sprintf-style string formatting. If it does not, you can use the sprintf plugin to enable support.

Feb 23, 2025 ​

Added the new Pretty Terminal Transport for LogLayer that pretty-prints logs in the terminal.

Simple View

Pretty Terminal Features ​

  • 🎨 Color-coded Log Levels - Each log level has distinct colors for quick visual identification
  • 🔍 Interactive Selection Mode - Browse and inspect logs in a full-screen interactive view
  • 📝 Detailed Log Inspection - Examine individual log entries with formatted data and context
  • 🔎 Search/Filter Functionality - Find specific logs with powerful filtering capabilities
  • 💅 JSON Pretty Printing - Beautifully formatted structured data with syntax highlighting
  • 🎭 Configurable Themes - Choose from pre-built themes or customize your own colors
  • 🔄 Real-time Updates - See logs as they happen with live updates
  • 📊 Context Awareness - View previous and next logs when inspecting entries

Feb 15, 2025 ​

in loglayer:

  • Added clearContext() to clear context data.
  • withMetadata() / metadataOnly() / withContext() now allows an empty value. Empty values will not result in any data mutations or plugin executions.

Feb 11, 2025 ​

Major version 6 is out! 🎉

This adds a new feature called Context Managers.

Breaking Changes ​

  • The linkParentContext configuration option has been removed. See the migration guide for more information on how to replicate the functionality.

Feb 8, 2025 ​

  • Added linkParentContext configuration option to allow child loggers to link to their parent's context. This enables changes to the context in either logger to affect both parent and child. Learn more
  • The plugin method runOnContextCalled is no longer called during child() if context data exists as it'd be a redundant call.

Feb 3, 2025 ​

  • Added a new method withFreshPlugins() to replace existing plugins with new ones in loglayer.

Jan 27, 2025 ​

  • Added an integration doc for Next.js to show how to implement LogLayer with Next.js.
  • Fixed the typings for metadataOnly() where the 2nd parameter should be optional.

Jan 24, 2025 ​

Jan 20, 2025 ​

  • Plugin callbacks now pass the loglayer instance as the last parameter.
  • Add the Axiom.co Transport.

Jan 18, 2025 ​

Add new options to the ConsoleTransport:

  • messageField: Allows you to specify the field in the log message object where the message should be stored. This is useful when you want to log structured data and need to specify the field name for the message.
  • level: Sets the minimum log level to process. Messages with a lower priority level will be ignored.

Jan 17, 2025 ​

  • Added the Log File Rotation Transport to write logs to files and rotate them
  • Performance improvements around using multiple transports with loglayer

Jan 15, 2025 ​