* [Mockzilla v2.11.0](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.

* [pikopod v0.2.0](https://github.com/Pikopod/pikopod) – Spec-based sandbox that fails on purpose and replays recorded production failures to help test and fix API integration retry and webhook handling paths.