Minimal Node.js app using Dev Proxy

Summary

This sample demonstrates the minimal setup to use Dev Proxy with a Node.js application. It shows how to:

• Configure Dev Proxy to intercept API requests
• Use Node.js 24’s built-in HTTP proxy support via NODE_USE_ENV_PROXY
• Mock API responses using the MockResponsePlugin
• Use top-level await (ES modules)

The sample makes a single API call to JSONPlaceholder and returns a mocked response, demonstrating how Dev Proxy intercepts and replaces the real API call using Node.js 24’s native proxy support.

Compatibility

Contributors

• Waldek Mastykarz

Version history

Prerequisites

• Dev Proxy
• Node.js 24+ (required for built-in proxy support)

Minimal path to awesome

• Get the sample:

  • Download just this sample:

    npx gitload-cli https://github.com/pnp/proxy-samples/tree/main/samples/minimal-node-js

    or

  • Download as a .ZIP file and unzip it, or

  • Clone this repository

• Navigate to the sample folder: cd samples/minimal-node-js
• Run npm install to install dependencies
• Run npm start to start Dev Proxy and the sample app
• Observe the mocked API response in the console with headers x-powered-by: Dev Proxy and x-mocked-by: Dev Proxy MockResponsePlugin

Features

This sample illustrates the following concepts:

• Configuring Dev Proxy with a .devproxy/devproxyrc.json file
• Using Node.js 24’s NODE_USE_ENV_PROXY for built-in HTTP proxy support
• Using top-level await with ES modules
• Using MockResponsePlugin to return custom API responses
• Adding custom headers to mocked responses

How it works

Node.js 24 introduced built-in HTTP proxy support. When NODE_USE_ENV_PROXY=1 is set, Node.js automatically routes fetch() requests through the proxy specified in HTTP_PROXY and HTTPS_PROXY environment variables. This eliminates the need for third-party proxy agents or manual proxy configuration.

NODE_USE_ENV_PROXY=1 HTTP_PROXY=http://127.0.0.1:8000 HTTPS_PROXY=http://127.0.0.1:8000 node app.js

Help

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Disclaimer

THIS CODE IS PROVIDED AS IS WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.