mitmproxy : mitmproxy is your swiss-army knife for debugging, testing, privacy measurements, and penetration testing. It can be used to intercept, inspect, modify...
Mockbin : Mockbin allows you to generate custom endpoints to test, mock, and track HTTP requests & responses between libraries, sockets and APIs.
mountebank : mountebank is the first open source tool to provide cross-platform, multi-protocol test doubles over the wire. Simply point your application under tes...
Zombie.js : Zombie.js is a lightweight framework for testing client-side JavaScript code in a simulated environment. No browser required.
Smocker : Smocker (server mock) is a simple and efficient HTTP mock server. Smocker exposes a configuration user interface and a configuration api to register n...
toxy is a fully programmatic and hackable HTTP proxy to simulate server failure scenarios and unexpected network conditions, built for node.js/io.js.