Slack adapter getting redirect_uri from the query params of request

[padapada09]

Bug Description

I have an issue where slack is not sending the redirect_uri to the callback as a query param, and I don't have a way of passing that to the adapter (aside from injecting it into the request which I'm doing as a temporal solution) given the fact that I might have multiple redirect uris I need to be able to specify which redirect_uri I'm using other wise the the code exchange fails with: bad_redirect_uri on line packages/adapter-slack/src/index.ts:601

Steps to Reproduce

1. Create a Chat instance
2. Setup slack adapter for Oauth configuration
3. Set up multiple redirects on api.slack.com
4. Get redirected to Oauth callback handler of Slack Adapter
5. Fails with bad_redirect_uri

Expected Behavior

The adapter should let me specify the redirect_uri and have the code exchange work fine

Actual Behavior

looks for the redirect_uri in the searchParams of the request and fails with bad_redirect_uri during code exchange

Code Sample

Chat SDK Version

4.21.0

Node.js Version

25.7.0

Platform Adapter

Slack

Operating System

macOS

Additional Context

No response

[bensabic]

Thanks for the report. This looks like a real gap in the Slack OAuth flow.

Right now handleOAuthCallback() reads redirect_uri from the callback request URL and forwards it to oauth.v2.access(), but there’s no supported way to provide that value explicitly. That breaks the case where you used a specific redirect_uri during the authorize step, especially if you have multiple valid redirect URLs configured, and Slack doesn’t reliably echo that back as a query param.

We should fix this by letting redirect_uri be passed explicitly rather than inferring it from request.url alone, likely with a per-callback option and possibly a config default for the simple case. For now, injecting it into the request is effectively the only workaround.