Hello developers!

We are changing the status code returned when an API client has hit its call limit. Presently, we use 503 Service Unavailable to indicate that a client has reached the call limit. 

As of November 30th, we will begin using status code 429 Too Many Requests (RFC 6585). 

Please ensure that your app can handle this change to guarantee expected functionality.

If you encounter any API issues or have any questions, you can visit the tech forums. Additionally, please be sure to monitor your email inboxes for further communications regarding this issue. You can also watch the Technology blog and @shopifyapi for updates.