Unable to receive token using 1/authorize and postMessage callback

Hello all!

I’m new to Trello REST API development and I’d appreciate guidance with my problem.

I’m trying to get token using 1/authorize route with postMessage callback and it’s not working as expected.
Url that I use:
https://api.trello.com/1/authorize?callback_method=postMessage&scope=read,write&expiration=1hour&name={{name}}&key={{apiKey}}&response_type=token&return_url={{callbackUrl}}

After successful login and authorization browser gets redirected to https://trello.com/1/token/approve, however no message is received at the endpoint (local azure function with ngrok tunelling).
Return url works fine when using callback_method=fragment.

Why usage of callback_method=postMessage doesn’t result in message getting sent to endpoint in this case?

Thank you for help,
Lukasz

Hi,

the behaviour is expected. postMessage callback triggers client-based auth flow. That’s why it doesn’t result in a message sent to the endpoint.

For your purposes, I recommend you use callback_method=fragment