Inspectr for Express

Inspectr is a NPM package that provides middleware for Express applications to capture and inspect every incoming request and outgoing response. It also includes a built‑in Inspectr UI (accessible at http://localhost:4004) where you can view request & response details in real time.

Features

• Express Middleware: Intercepts HTTP requests and responses and webhooks.
• Real-time Inspector: Inspect Requests & Responses in the Inspectr App.
• Log Requests: Log request data to the console.
• Easy Integration: Simply add the middleware to your Express app.

Installation

Install the package via npm:

npm install @inspectr/express

Usage

1. Integrate the Inspectr Middleware into Your Express Application

In your Express application, require the package and use the middleware. For example:

// app.js
const express = require('express');
const inspectr = require('@inspectr/express');

const app = express();

// (Optional)Set the broadcast URL for Inspectr.
// inspectr.setBroadcastUrl('http://localhost:4004/sse');

// Add the inspectr middleware BEFORE your routes
app.use(inspectr.capture);

// Define your routes
app.get('/', (req, res) => {
 res.send('Hello, world!');
});

// Start your Express server as usual
const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
 console.log(`Express app listening on port ${PORT}`);
});

2. Configuration Options

The capture() function accepts an optional configuration object to control how request and response data is handled:

| Option | Type | Default | Description | |:------------|:--------|:--------|:-------------------------------------------------------------------------------------------| | broadcast | boolean | true | If true, sends request/response data to the SSE for real-time viewing in the Inspectr App. | | print | boolean | true | If true, logs request/response details to the console in a structured format. |

Examples Enable only console logging (disable SSE broadcasting):

app.use((req, res, next) => {
  inspectr.capture(req, res, next, { broadcast: false, print: true });
});

Enable only SSE broadcasting (disable console logging):

app.use((req, res, next) => {
  inspectr.capture(req, res, next, { broadcast: true, print: false });
});

Or access the data directly

// Add the inspectr middleware BEFORE your routes
app.use((req, res, next) => {
  inspectr(req, res, next, { broadcast: true, print: true })
    .then(data => {
      // Optionally, process the captured data (e.g., log it)
      console.log('Captured data:', data);
    })
    .catch(err => {
      console.error('Inspectr error:', err);
      next(err);
    });
});

Use default behavior (both enabled):

app.use(inspectr.capture);

3. Run the Inspectr App

The Inspectr App is provided as a separate command-line tool that serves the App on port 4004. Once your app is running ( and using the middleware), you can start the Inspectr App in another terminal:

If you installed the package locally:

  @inspectr/express

or as package.json script

"scripts": {
 "inspectr-app": "inspectr"
}

Then open your browser to http://localhost:4004 to view the inspectr interface.