Mailbox API 2.0

Welcome to the second generation of our Mailbox API. This is an HTTPS-only API, with OAuth 2 authentication and CORS support running at:

It uses JSON for requests, responses and error messages. The responses typically include resource links which should help you explore the API and free you from composing URIs by hand.

Previous API version

The V1 API is still supported in a maintenance capacity and only security patches will be backported. All new features will only be added to V2 from now on, if there are any features you’d like to see included in our Mailbox API 2.0, be sure to let us know. A summary of the main differences between the versions is available here.

Authors of Help Scout integrations can use our Transition service to exchange V1 API keys for OAuth2 tokens.


While we won’t introduce any breaking changes, we plan on adding new features and new endpoints over time. Our changelog can be monitored to see when and how the API was updated.


We have also been working on example PHP and Java SDKs, but we haven’t decided how (and if) we are going to release them, please let us know if you’d be interested in these clients being made available.