@replayapi/node

ReplayAPI SDK for Node.js — Automatically capture outgoing HTTP traffic for replay testing.

Install

npm install @replayapi/node

Quick Start

import { replayApi } from '@replayapi/node'

// Initialize once at app startup
replayApi.init({
  apiKey: process.env.REPLAY_API_KEY!,
  environment: 'staging',
})

// That's it — all http, https, and fetch calls are now captured

Configuration

replayApi.init({
  // Required
  apiKey: 'rp_your_api_key',

  // Optional
  proxyUrl: 'http://localhost:8080',  // Default proxy URL
  environment: 'staging',             // Environment label
  sessionId: 'user-checkout-flow',    // Group related requests

  // Filter what gets captured
  include: ['api.example.com', /\/api\/v\d+\//],
  exclude: ['healthcheck', /\.internal\./],

  // Debug
  debug: true,                        // Enable verbose logging
  disabled: false,                    // Disable without removing code
  timeout: 30000,                     // Proxy request timeout (ms)
})

API

replayApi.init(config)

Initialize the SDK. Patches http.request, https.request, and fetch globally.

replayApi.stop()

Stop capturing and restore original HTTP behavior.

replayApi.isActive()

Returns true if the SDK is currently intercepting traffic.

replayApi.getStats()

const stats = replayApi.getStats()
// { totalCaptured: 42, totalSkipped: 3, totalErrors: 0, startedAt: Date }

How It Works

1. Your app makes an HTTP request: GET https://api.example.com/users
2. The SDK rewrites it to: GET http://proxy:8080/users with headers:
   • X-Api-Key: rp_... (your API key)
   • X-Replay-Target: https://api.example.com (original target)
   • X-Replay-Env: staging (environment)
3. The proxy captures the traffic, forwards to the target, returns the response
4. Your app receives the response as if the proxy wasn't there

Supported

• Node.js 18+ (native fetch support)
• http.request / http.get
• https.request / https.get
• globalThis.fetch
• Libraries that use these under the hood (axios, node-fetch, got, etc.)