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.


Version 2.0 of our PHP SDK client has been updated to support Mailbox API 2.0.

Important to note: For now, the 2.x releases will target the v2 branch in GitHub while the 1.x releases will continue to be made off the existing master branch. On March 1st, 2019, we’ll merge the v2 branch into master and will begin tagging releases from here. If your project is targeting ‘dev-master’ in your composer.json file, things will break. We will continue to support v1.x releases until June 6th, 2019. At that time, Mailbox API 1.0 will be shut down.

In addition to this release, we’ve also released version 1.0 of the Laravel/Lumen adapter for the API client. If you’re using the v2 client within a Laravel/Lumen app, this adapter contains a handy service provider and facade to make things a little easier.

If you’d like to request support for any other clients, please let us know.