OpenHeaders is a local-first HTTP toolkit: modify live browser requests, build and run API collections, and share your setup with your team. It ships as a browser extension and a desktop app that work alone or together, plus a CLI and a server for automation and CI.

There is no account and no cloud — your data stays on your machine, and every feature is free. Paid plans exist only to add team seats. The source code is open under Apache-2.0 in open-headers.

The desktop app, CLI, and server are on the releases page. The extension is on the Chrome, Firefox, and Edge stores. Documentation lives at openheaders.com.

Bug reports and feature requests belong on the issue tracker, questions and ideas in discussions.

Report vulnerabilities to security@openheaders.com. The security policy includes a safe harbor for good-faith research.

Every network call the apps make is documented byte-for-byte.