0.0.19 • Public • Published

npm version

HAR Proxy Server

HAR Proxy Server is a simple proxy server that records and plays back HTTP requests and responses in HAR format. It can be used as a standalone executable or integrated into other projects as an npm package.


  • Record HTTP requests and responses to a HAR file.
  • Playback recorded requests and responses from a HAR file
  • Serve requests over HTTP or HTTPS.
  • Configurable playback endpoint prefix
  • Middleware support for Express.js.
  • Command-line interface for easy configuration
  • Utility to filter HAR files to extract only required HTTP/S requiests.
  • Utility to sanitize headers and cookies from har files


To install the server as a global command-line utility:

npm install --location=global harproxyserver


Standalone Executable

Run the server using the harServer command:

Start the server in play mode (default)

harproxyserver -p 3000 -f recorded.har

Start the server in record mode

harproxyserver -p 3000 -t http://example.com -f recorded.har -m record

Start the server with HTTPS

harproxyserver -p 3000 -f recorded.har --tls --key-file server.key --cert-file serv

Filter HAR file, to return only requests containing "forklift.konveyor.io" or "forklift-console-plugin" in the URL.

node dist/harProxyServer.js -m filter -f recorded.har --filter-endpoint-regexp "forklift.konveyor.io|forklift-console-plugin"


Import the server and utility functions in your TypeScript project:

import { findHarEntry, recordedHarMiddleware } from 'harproxyserver';

Example 1: Using findHarEntry to find a specific GET request in a HAR log:

const harLog = ... // retrieve HAR log
const method = 'GET';
const pathname = '/api';

const entry = findHarEntry(harLog, method, pathname);

if (entry) {
  console.log(`Found entry with ID ${entry.id}`);
} else {
  console.log('Entry not found');

Example 2: Using findHarEntry to find a POST request with specific query parameters:

const harLog = ... // retrieve HAR log
const method = 'POST';
const baseUrl = 'https://example.com/api';
const queryParams = { q: 'search term', page: 1 };

const url = new URL(baseUrl);
for (const [key, value] of Object.entries(queryParams)) {
  url.searchParams.set(key, value);
const pathnameWithParams = `${url.pathname}${url.search};

const entry = findHarEntry(harLog, method, pathnameWithParams);

if (entry) {
  console.log(`Found entry with ID ${entry.id}`);
} else {
  console.log('Entry not found');

Command-Line Options

The available options for this tool are:

  • --port, -p : The port the server will listen on (default: 3000).
  • --target-url, -t : The target URL to proxy when in 'record' mode.
  • --har-file, -f : The file path to save the HAR file (default: recording-[date and time].har).
  • --prefix : The prefix for the HAR playback endpoint (default: '').
  • --mode, -m : The mode to run the server in (default: 'play'). Choices are 'play', 'record' or 'filter'.
  • --tls: Run the server in secure mode (HTTPS) (default: false).
  • --key-file : Path to the TLS private key file (required when using --tls).
  • --cert-file : Path to the TLS certificate file (required when using --tls).
  • --filter-endpoint-regexp : RegExp to use when filtering a har file (filtered har file will include only matching endpoints)
  • --sanitize : Remove headers and cookies when filtering a har file


This project is licensed under the Apache License 2.0. See the LICENSE file for details.

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