A lightweight gateway programmable with JavaScript.
JSRealm lets you route requests, rewrite URLs, and proxy to backends using Web APIs you already know — fetch(), Request, Response, Headers. Write your gateway logic in JavaScript, get auto HTTPS with ACME, and scale to 300k+ req/sec on a single machine.
Single binary. Zero dependencies. Top-tier performance with top-tier usability.
var app = new App();
app.get('/hello/:name', (request, params) => {
return new Response(`Hello, ${params.name}!`);
});
app.all('/api/*', (request) => {
return fetch(request, {
target: 'http://backend.internal:3000'
});
});
export default app;Features
- HTTP/1.1 with keep-alive
- HTTPS with automatic certificates (ACME/Let's Encrypt)
- JavaScript support (ES2023)
- Routing with path params and wildcards
- fetch() for proxying requests
- Authentication hooks
- Response headers
- Path rewrite
- Gzip compression
Quick Start
# Download the latest release
wget https://github.com/lre66/jsrealm/releases/latest/download/jsrealm-linux-x86_64.tar.gz
tar xzf jsrealm-linux-x86_64.tar.gz
# Create app
mkdir myapp && cd myapp
echo '{"http": "0.0.0.0:8080"}' > config.json
cat > app.js << 'EOF'
var app = new App();
app.get('/', () => new Response('Hello, World!'));
export default app;
EOF
# Run
../jsrealm
# Test
curl http://localhost:8080/