feature request: Support OIDC "select_account" prompt

[michaelfried]

Describe the bug

I want to use logto as an external idp. I therefore created a "Third-Party App" application for generic OIDC in Logto.
I'm now integrating logto into another auth provider (zitadel in this case). When I now start the authorization flow logto returns the error "unsupported prompt value requested".

Auth request: https://logto.company.tld/oidc/auth?client_id=<clientId>&prompt=select_account&redirect_uri=https%3A%2F%2Fzitadel.company.tld%2Fui%2Flogin%2Flogin%2Fexternalidp%2Fcallback&response_type=code&scope=openid+profile+email&state=301172077472251908

Redirect: https://zitadel.company.tld/ui/login/login/externalidp/callback?error=invalid_request&error_description=unsupported+prompt+value+requested&state=301172077472251908&iss=https%3A%2F%2Flogto.company.tld%2Foidc

When I adapt the prompt in the auth requests to consent or login it works, however it doesn't with select_account or none.

I unfortunately didn't find any documentation or settings regarding this.

Expected behavior

Logto should be able to handle the select_account OIDC prompt.

How to reproduce?

Integrate generic OIDC app created in logto as an external idp in a different auth provider.

Context

• Logto Cloud
• Self-hosted, Logto version = v1.23.0
  • Container (Docker image)
  • Raw Node.js

[michaelfried]

After having a look at the implementation I've realised that this has not been implemented, therefore it's probably more of a feature request than a bug. However I do think the prompt options described in this blog should be supported.

logto/packages/core/src/oidc/init.ts

Lines 221 to 233 in 460ea89

	switch (prompt.name) {
	case 'login': {
	return '/' + buildLoginPromptUrl(params, appId);
	}
	case 'consent': {
	return '/' + experience.routes.consent;
	}
	default: {
	throw new Error(`Prompt not supported: ${prompt.name}`);
	}
	}

[wangsijie]

@charIeszhao can you check on this?

[charIeszhao]

Select account feature is not yet supported when using Logto as a third party Idp.

The blog post, however, is just an tech article trying to explain how "Prompt" works in OIDC 2.0 protocol to general readers.

We would turn this issue into a feature request, and you can also submit your request on our productlane: https://logto.productlane.com/roadmap