We have reports of users not being able to install the RevenueCat MCP (https:// mcp.revenuecat. ai/mcp) server as it fails to run the authorization.
It fails to perform the authorization code exchange as it is using an invalid url for the token endpoint, https:// api.revenuecat. com/token instead of https:// api.revenuecat. com/oauth2/token as exposed by the authorization server metadata (https: // mcp.revenuecat. ai/.well-known/oauth-authorization-server): "token_endpoint":"https: // api.revenuecat. com/oauth2/token"
(had to add spaces to the urls as it complained about being too many…)
Steps to Reproduce
Install the mcp (https: //cursor. com/en/install-mcp?name=revenuecat&config=eyJ1cmwiOiJodHRwczovL21jcC5yZXZlbnVlY2F0LmFpL21jcCJ9)
Thanks for the detailed report and the pointer to the authorization server metadata. You’ve correctly identified the issue: when the token endpoint is on a non-default path (like /oauth2/token), Cursor isn’t using the token_endpoint value from the authorization server metadata and instead falls back to an incorrect URL.
This is a known issue affecting MCP servers that use a separate authorization server with custom token endpoint paths. You can see similar reports from users of other MCP providers in this thread.
Our engineering team is actively working on a fix. Unfortunately there isn’t a client-side workaround available right now since the issue is in the internal token exchange logic.
We’ll make sure this report is tracked alongside the fix effort. Apologies for the inconvenience.
Could you share what specific error you’re seeing and your exact Cursor version (Help > About)? For example, does the authorization flow open in the browser, and does it fail with a 404 during the token exchange step?
Several OAuth improvements have shipped since this thread was opened, but there may still be cases that need additional work. Could you please create a new thread with the specifics so we’re able to better track and address the issue?
Hi,
I am using 3.3.0 and after I added RevenueCat MCP as described at their web site ( RevenueCat MCP Server Setup | In-App Subscriptions Made Easy – RevenueCat , only change was servers should be mcpServers according to linter) I can see RevenueCat at MCP List with a button Connect.
After pressing Connect button, RevenueCat web page opens and I click Authorize button than returning back to cursor.
This time Cursor says Error - Show output below RevenueCat listing at MCP list.
2026-05-10 15:33:08.408 [error] OAuth fallback failed after MCP server returned 401 for configured Authorization header; surfacing original 401 Streamable HTTP error: Server returned 401 after successful authentication
2026-05-10 15:33:08.409 [warning] Connection failed: HTTP 401 Unauthorized from MCP server while using configured Authorization header
Looking at your error logs, this is actually a different issue from what this thread originally tracked. The original bug was a 404 during the token exchange step (wrong URL), which has since been fixed. Your error is a 401 after the OAuth flow completes — meaning the token exchange itself succeeds, but the token is then rejected by RevenueCat’s server when Cursor tries to connect.
Could you create a new thread for this so our team can properly track it? Please include:
Your full Cursor version (Help > About — paste the full block)
The MCP output logs you shared here
Your exact mcp.json / MCP config
Whether this is your first time trying RevenueCat MCP, or if it worked before on an earlier version
That will help us investigate the 401 specifically rather than it getting lost in this resolved thread.