@senzops/apm-worker

The official Serverless & Worker SDK for Senzor APM.

Designed specifically for Cloudflare Workers, Cloudflare Pages, Nitro, and modern Edge runtimes.

✨ Features

• Zero-Config Auto-Instrumentation: Automatically captures all global fetch calls.
• Context Propagation: Uses AsyncLocalStorage (via nodejs_compat) to track requests across async boundaries without manual passing.
• Lightweight: < 5KB gzip, zero external dependencies.
• Non-Blocking: Uses ctx.waitUntil to flush data without adding latency to user responses.
• W3C Trace Context: Automatically injects traceparent headers into outgoing requests for distributed tracing.

📦 Installation

npm install @senzops/apm-worker

🚀 Quick Start (Cloudflare Workers)

1. Enable Node Compatibility

Add the nodejs_compat flag to your wrangler.toml. This is required for the SDK to track context across async fetch calls.

# wrangler.toml
compatibility_flags = [ "nodejs_compat" ]
compatibility_date = "2024-09-23"

2. Integrate the SDK

Initialize Senzor in the global scope and wrap your fetch handler.

import { Senzor } from "@senzops/apm-worker";

Senzor.init({
  apiKey: "sz_apm_...",
});

export default {
  fetch: Senzor.worker(async (request, env, ctx) => {
    return new Response("Hello World!");
  }),
};

⚡ Usage with Nitro / Nuxt

For Nitro (standalone) or Nuxt, use a server plugin to instrument the entire application globally without wrapping individual handlers.

1. Create a Plugin

Create server/plugins/senzor.ts:

import { Senzor } from "@senzops/apm-worker";

export default defineNitroPlugin((nitroApp) => {
  // 1. Initialize
  // Use process.env or runtime config if available
  Senzor.init({
    apiKey: process.env.SENZOR_API_KEY || "sz_apm_...",
  });

  // 2. Register Global Instrumentation
  Senzor.nitroPlugin(nitroApp);
});

2. Configuration

Ensure nodejs_compat is enabled in your nitro.config.ts:

// nitro.config.ts
export default defineNitroConfig({
  cloudflare: {
    wrangler: {
      compatibility_flags: ["nodejs_compat"],
    },
  },
});

That's it! Every request to your Nitro app is now traced, and any fetch calls made within your API routes will automatically appear as spans in the trace.

📋 Production Checklist

1. Environment Variables

For security, do not commit your API key.

1. Run npx wrangler secret put SENZOR_API_KEY.
2. Update your worker to initialize lazily or use build-time variables.

2. Distributed Tracing

If your Worker calls other services (like a backend API), this SDK automatically adds the traceparent header. Ensure your backend services (Node.js, Python, Go) are configured to extract this header to see a connected trace from Edge -> Backend.

3. Error Tracking

Any uncaught exception thrown in your handler is automatically captured, logged, and reported to Senzor with the stack trace.