Lightweight Express middleware for serving interactive ReDoc API documentation from OpenAPI/Swagger specs with full TypeScript support and zero configuration overhead.
- 🚀 Lightweight & Fast - Minimal overhead, serves static documentation
- 📝 Full TypeScript Support - First-class TypeScript support with complete type definitions
- ✅ 100% Test Coverage - Comprehensive test suite with 136 test cases covering all functionality
- 🎨 Customizable UI - Full ReDoc theming and configuration support
- 🔒 Secure - Built-in CSP nonce support for enhanced security
- 📦 ES5 Compatible - Works across all Node.js versions (Node 6+)
- 🔧 Zero Config - Works out of the box with sensible defaults
- 🧩 OpenAPI/Swagger - Support for both OpenAPI 3.0+ and Swagger 2.0 specifications
redoc-express makes it dead simple to add professional API documentation to your Express server. Unlike alternatives:
- No build tools required
- Single middleware setup
- Works with your existing OpenAPI/Swagger spec
- Highly customizable but requires no configuration to get started
- Production-ready with 100% code coverage and 136 comprehensive tests
npm install redoc-expressconst express = require('express');
const redoc = require('redoc-express');
const app = express();
const port = 3000;
// Serve your OpenAPI/Swagger spec
app.get('/docs/swagger.json', (req, res) => {
res.sendFile('swagger.json', { root: '.' });
});
// Mount ReDoc middleware
app.get(
'/docs',
redoc({
title: 'API Documentation',
specUrl: '/docs/swagger.json'
})
);
app.listen(port, () => {
console.log(`📚 API docs available at http://localhost:${port}/docs`);
});import express, { Express } from 'express';
import redoc from 'redoc-express';
const app: Express = express();
const port = 3000;
// Serve your OpenAPI/Swagger spec
app.get('/docs/swagger.json', (req, res) => {
res.sendFile('swagger.json', { root: '.' });
});
// Mount ReDoc middleware with TypeScript support
app.get(
'/docs',
redoc({
title: 'API Documentation',
specUrl: '/docs/swagger.json',
redocOptions: {
theme: {
colors: {
primary: { main: '#1976d2' }
}
}
}
})
);
app.listen(port, () => {
console.log(`📚 API docs available at http://localhost:${port}/docs`);
});app.get(
'/docs',
redoc({
title: 'My API Documentation',
specUrl: 'https://api.example.com/openapi.json',
nonce: 'random-nonce-123', // Optional: for CSP compliance
redocOptions: {
theme: {
colors: {
primary: { main: '#6EC5AB' }
},
typography: {
fontFamily: '"museo-sans", Helvetica, Arial, sans-serif',
fontSize: '15px'
},
menu: { backgroundColor: '#ffffff' }
},
hideDownloadButton: true,
expandResponses: '200,201,400'
}
})
);For all available ReDoc configuration options, see the official documentation
| Option | Type | Required | Description |
|---|---|---|---|
title |
string | Yes | Title displayed in the browser tab and header |
specUrl |
string | Yes | URL to your OpenAPI/Swagger specification file |
nonce |
string | No | Security nonce for Content Security Policy compliance |
redocOptions |
object | No | ReDoc configuration options |
- Node.js: 6+ (ES5 compatible)
- Express: 4.x, 5.x
- OpenAPI: 3.0+, Swagger 2.0
- TypeScript: 3.5+
npm inpm testnpm run build| Metric | Coverage |
|---|---|
| Statements | 100% |
| Branches | 100% |
| Functions | 100% |
| Lines | 100% |
136 comprehensive test cases organized across 3 test suites:
-
Unit Tests - redocHtml (85+ tests)
- HTML structure and DOCTYPE validation
- Title handling (unicode, emoji, special characters, extreme lengths)
- URL/Spec handling (protocols, authentication, fragments, long URLs)
- Nonce validation and CSP compliance
- ReDoc options configuration (objects, arrays, numbers, booleans)
- JSON serialization and escaping
-
Unit Tests - redocExpressMiddleware (51+ tests)
- Express middleware behavior and method ordering
- Content-type and response handling
- Request/response immutability
- Multiple middleware invocations
- Edge cases and error handling
-
End-to-End Tests (26+ tests)
- Real-world Express integration scenarios
- Concurrent request handling
- Multiple API documentation versions
- Route isolation and middleware chains
- Stress testing with rapid requests
npm test # Run all 136 tests
npm test -- --coverage # With coverage report
npm test -- --watch # Watch mode during developmentAll tests pass with 100% code coverage in approximately 1-2 seconds.
Q: Can I use this with TypeScript? A: Yes! Full TypeScript support with included type definitions.
Q: Does this work with OpenAPI 3.0? A: Yes, both OpenAPI 3.0+ and Swagger 2.0 are supported.
Q: Is there a performance impact? A: Minimal. The middleware only serves static HTML—no runtime overhead.
Q: Can I customize the UI colors/fonts?
A: Yes, pass redocOptions with your theme configuration.
Q: What Node.js versions are supported? A: Node 6+ (ES5 compiled output). Development requires Node 18.14+.
MIT © Aung Myo Kyaw