WttpA local, open source HTTP client

Develop, test and document APIs — workspaces are YAML files you version in Git. No account, no cloud.

Local-first

Workspaces, collections and environments are folders of YAML files on your machine. One file per request.

Deterministic serialization — saving without changes produces identical bytes, and diffs show only what changed.

Secret variables go to the OS keychain, never to YAML.

Sandboxed JavaScript before and after every request, with assertions and variables shared across requests.

Postman, Insomnia, OpenAPI and cURL.

The interface and this documentation in both languages.