What is a valid return_url when using client.js for authentication?

[Tester Gcal]

When i do Trello.authorize(opts), Am always receiving invalid return_url as the response irrespective of the value that i pass.

What is a  proper return_url?

[David Bernal]

The URL may not use the data or javascript protocols, but any other should be fine. The exception would be if you have set "Allowed Origins" on https://trello.com/app-key. In that case, the return_url must also match your Allowed Origins. When using client.js, the `return_url` is based on the page you are currently on, so if the page you're on doesn't match your Allowed Origins, or uses one of those protocols, you might receive this error.

Does this help?