Proxy Events
May 3, 2026 ยท View on GitHub
Subscribe to httpxy events: error, proxyReq, proxyReqWs, proxyRes, open, close, start, end, econnreset.
on.error
Subscribe to httpxy's error event.
import { createProxyMiddleware } from 'http-proxy-middleware';
const onError = function (err, req, res) {
console.log('Something went wrong.');
console.log('And we are reporting a custom error message.');
};
const options = {
target: 'http://localhost:3000',
on: { error: onError },
};
const apiProxy = createProxyMiddleware(options);
on.proxyReq
Subscribe to httpxy's proxyReq event.
import { createProxyMiddleware } from 'http-proxy-middleware';
const onProxyReq = function (proxyReq, req, res) {
// add new header to request
proxyReq.setHeader('x-added', 'foobar');
};
const options = {
target: 'http://localhost:3000',
on: { proxyReq: onProxyReq },
};
const apiProxy = createProxyMiddleware(options);
on.proxyReqWs
Subscribe to httpxy's proxyReqWs event.
import { createProxyMiddleware } from 'http-proxy-middleware';
const onProxyReqWs = function (proxyReq, req, socket, options, head) {
// add custom header
proxyReq.setHeader('X-Special-Proxy-Header', 'foobar');
};
const options = {
target: 'http://localhost:3000',
on: { proxyReqWs: onProxyReqWs },
};
const apiProxy = createProxyMiddleware(options);
on.proxyRes
Subscribe to httpxy's proxyRes event.
import { createProxyMiddleware } from 'http-proxy-middleware';
const onProxyRes = function (proxyRes, req, res) {
// add new header to response
proxyRes.headers['x-added'] = 'foobar';
// remove header from response
delete proxyRes.headers['x-removed'];
};
const options = {
target: 'http://localhost:3000',
on: { proxyRes: onProxyRes },
};
const apiProxy = createProxyMiddleware(options);