* [Mockzilla v2.7.0](https://github.com/mockzilla/mockzilla) – OpenAPI-based mock server that generates realistic responses, validates requests, simulates latency and errors, and proxies with automatic mock fallback.

* [Hoppscotch 2026.5.0](https://github.com/hoppscotch/hoppscotch) – Lightweight API development ecosystem with real-time request sending and customizable theming.

* [Keploy v3.5.56](https://github.com/keploy/keploy) – Developer-centric API testing tool that creates tests and built-in mocks faster than unit tests.

* [Rustman v0.3.1](https://github.com/animeshchaudhri/rustman) – Lightweight desktop API testing app with native Rust HTTP engine, async pre/post scripts, test runner, and Postman compatibility.

* [Node.js Tusk Drift SDK v0.1.45](https://github.com/Use-Tusk/drift-node-sdk) – Node.js SDK that captures and replays service API calls to enable fast, deterministic testing.