koa-mock-proxy is a tool for creating proxy servers with the ability to record and replay responses (mocks).

It can be useful for:

• service/integration tests (in case you want to test only frontend)
• e2e tests mocking only chosen endpoints
• Manually testing application without backend or for a specific scenario that's difficult to reproduce
• Logging activity between services

You are free to use all possibilities of Koa (custom middlewares like koa-router).

• Proxy http requests
• Record requests and responses (body and headers) into human-readable files
• Log proxy requests, view it using the UI
• Manage different test scenarios (depending on a scenario, the same endpoint can return different responses)

• A public API made in a very familiar way for many JS developers (using middlewares)
• Recorded mocks are suitable to put in a version control system, easy to understand and update
• Composability with other libraries and code from custom mocks
• UI for easier debugging and recording of mocks

Install using npm:

npm i koa-mock-proxy

Also, it's necessary to install koa, if you don't have it in your project:

npm i koa

Full docs are available here

And a lot of examples are here

You can set env variable DEBUG_PROXY=true if you want to see in console all requests coming through mock server.