Loggable Object

A TypeScript decorator that adds logging capabilities to Cloudflare Durable Objects with persistent storage and live streaming. Especially useful for logging in alarms in production DOs as these aren't normally visible.

Usage

1. npm i loggable-object
2. Add @Loggable before your DO, and log: Log; as first line in your DO (for type safety)
3. Use logs anywhere, also in alarms, via this.log
4. Expose your DO /log endpoint safely
5. curl https://yourworker.com/log for a log stream!

Complete example

See example.ts and wrangler.toml

Features

• TypeScript Decorator: Clean decorator syntax using @Loggable
• Multiple Log Levels: Support for log (info), warn, and error levels
• Filtering & Searching: Get exactly the logs you need
• Chronological Order: Logs are displayed oldest-first for better readability

Log Levels

The log method accepts a log level as the first parameter:

this.log("log", "Info message"); // Info level
this.log("warn", "Warning message"); // Warning level
this.log("error", "Error message"); // Error level

Accessing Logs

Live Log Stream

Visit /log on your Durable Object to get a live stream of logs in text format:

curl http://localhost:8787/log

This will:

1. First stream all historical logs (oldest to newest)
2. Show a separator line: --- Live logs start here ---
3. Continue streaming new logs in real-time as they occur

API Filtering Options

You can filter logs using URL parameters:

# Get only error logs
curl "http://localhost:8787/log?level=error"

# Search for specific text
curl "http://localhost:8787/log?search=startup"

# Get logs from a specific time range
curl "http://localhost:8787/log?from=2023-09-01T00:00:00Z&to=2023-09-02T00:00:00Z"

# Limit results with pagination
curl "http://localhost:8787/log?limit=50&offset=100"

Available filter parameters:

• level: Filter by log level (log, warn, error)
• search: Search within log messages
• from: Start timestamp (ISO string)
• to: End timestamp (ISO string)
• limit: Maximum number of logs to return (default: 100)
• offset: Pagination offset