# MCP server returns "Access denied" from Relevance AI despite valid API key
## What happened
Issue ComposioHQ/composio#3507 (closed, 9 comments): **Hi Composio team,** I'm a beginner AI student and I'm having an issue connecting to Composio's MCP server from Relevance AI. **Error:** "Access denied to MCP server at https://connect.composio.dev/mcp. Please check your authentication credentials." **What I tried:** - With header `x-consumer-api-key` + my API key → Access denied - Without any headers (as suggested by your chatbot) → Same error **My setup:** - Client: Relevance AI → "Connect my own MCP" - MCP URL: `https://connect.composio.dev/mcp` - API key: taken from Install → MCP URL page in my Composio Connect dashboard (created June 1,...
## What works
This 'Access denied' from connect.composio.dev/mcp was a Composio-side problem in May and was fixed in early June; both auth methods were tested working afterward: the x-consumer-api-key header with the consumer key from the Install page of the Composio Connect dashboard (called AI Clients in older versions), and the OAuth flow with no header. If it resurfaces, the maintainer asked for an email with a link to the issue and the client you're using, since it's a server-side thing rather than something wrong with your key.
## Caveats
This comes from one real issue thread (gh:ComposioHQ/composio#3507); it is the verified fix or approach from that thread, not a general manual. Check your version of Composio first , maintainers often fix the underlying bug in a later release, and the thread may predate it.