Our IdP’s ‘/authorize’ endpoint supports additional ‘invitation’ and ‘organization’ query parameters that enable more functionality in our IdP.  Insided’s ‘/ssoproxy/login’ endpoint does not forward additional query parameters to our IdP’s ‘/authorize’ endpoint. 

More specifically, while users can still authenticate, this causes users’ invitations to remain in the ‘Pending’ status.  Additionally, without a valid invitation id we cannot conditionally enable sign-ups in our IdP and thus need to disallow signups for all users.  This in turn forces us to create the user with a bogus password before inviting them; which is a sub-optimal user experience.

Beyond our IdP’s scenario there are potentially other benefits to allowing additional sso parameters.

This could be implemented by simply forwarding any additional query parameters that are appended to Insided’s ‘ssoporxy/login’ endpoint to the configured ‘Auth URI’.  Maybe a checkbox could be added to the integration sso settings page to enable custom query parameters if you don’t want this to be the default functionality.