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Cloudflare Workers

@pydantic/logfire-cf-workers instruments Cloudflare Workers and exports the manual logfire API through the core logfire package.

Install

Terminal
npm install @pydantic/logfire-cf-workers logfire

Enable Node.js compatibility in Wrangler:

wrangler.jsonc
{
  "compatibility_flags": ["nodejs_compat"]
}

For local development, set a write token in .dev.vars:

.dev.vars
LOGFIRE_TOKEN=your-write-token
LOGFIRE_ENVIRONMENT=development

For production, store LOGFIRE_TOKEN as a Worker secret.

In-Process Instrumentation

import * as logfire from 'logfire'
import { instrument } from '@pydantic/logfire-cf-workers'

const handler = {
  async fetch(): Promise<Response> {
    logfire.info('worker request handled')
    return new Response('hello from Logfire')
  },
} satisfies ExportedHandler

export default instrument(handler, {
  service: {
    name: 'checkout-worker',
    namespace: '',
    version: '1.0.0',
  },
})

instrument() is an alias for instrumentInProcess(). It reads LOGFIRE_TOKEN, LOGFIRE_ENVIRONMENT, and LOGFIRE_BASE_URL from the Worker environment.

Tail Workers

The package also supports Cloudflare Tail Worker flows:

  • use instrumentTail() in the producer Worker
  • use exportTailEventsToLogfire() in the Tail Worker

See examples/cf-producer-worker and examples/cf-tail-worker in this repository for the full wiring.

Scrubbing

Pass scrubbing to control sensitive data scrubbing before telemetry is sent:

export default instrument(handler, {
  scrubbing: {
    extraPatterns: ['secret_token'],
  },
  service: {
    name: 'checkout-worker',
    namespace: '',
    version: '1.0.0',
  },
})