AWS MCP callback URL issue

Support Bug Reports
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1

I’m trying to connect the AWS MCP Server to Cursor Cloud, and the OAuth flow is failing with this error (screenshot from Cursor):

Screenshot 2026-09-02 at 2.51.07 PM
Screenshot 2026-09-02 at 2.51.07 PM682×180 11.4 KB

From AWS’s documentation, it looks like the supported Cursor Cloud callback is:

However, Cursor is currently sending:

https://www.cursor.com/bot/mcp/oauth/callback

Could you confirm whether this is a known issue with Cursor Cloud / background agents?

Specifically:

Should Cursor Cloud be using /agents/mcp/oauth/callback instead of /bot/mcp/oauth/callback? Is there a configuration or workaround I can use to change the callback URI? If not, does Cursor need to coordinate with AWS to have the /bot/ callback added to AWS MCP’s OAuth redirect allowlist?

This is specifically affecting the cloud version of aws-mcp. My local AWS CLI authentication/profile works correctly

2

I have exactly the same problem since yesterday. Before that, I have been running these AWS MCP calls successfully for over three weeks using the cloud agent.

3

Hi there!

We detected that this may be a bug report, so we’ve moved your post to the Bug Reports category.

To help us investigate and fix this faster, could you edit your original post to include the details from the template below?

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8

Hey @simon604, thanks for the reportand thanks @Workshop_Admin for confirming the timing!

You’ve read this correctly. Cursor Cloud does use https://www.cursor.com/agents/mcp/oauth/callback as its redirect URI, but a recent change on our side started including an additional callback URL (the /bot/ one in your screenshot) in the client registration we send to MCP servers.

AWS validates every URL in that list against its allowlist, so it rejects the entire registration before the sign-in page ever loads. That’s also why this worked for weeks and then suddenly stopped.

There’s no setting on your end that affects this, and you don’t need to ask AWS to allowlist anything. The fix is on our side, and we’ll keep this thread updated.