About Application Services login

Encrypted Application Services/Bridges currently leverage the m.login.application_service login type to create devices for users. This API is not available in the Matrix Authentication Service: as per Matrix 1.19, calling /login with this login type returns a 400 HTTP status code with an M_APPSERVICE_LOGIN_UNSUPPORTED error code.

We’re working on a solution to support this use case, but in the meantime, this means encrypted bridges will not work with the Matrix Authentication Service. A workaround is to disable E2EE support in your bridge setup.