<currently not being actively maintained>
Insomnium is a 100% local and privacy-focused open-source API client for testing GraphQL, REST, WebSockets, Server-sent events and gRPC in development/production.
- ✅ works 100% offline, the way a local testing tool should behave
- ✅ no cloud services, no tracking/communication to external servers behind the scene
Insomnium is no longer maintained and since the original repo has been archived, no one can answer the question of alternatives.
There is a similar project here: