Urgent Help Needed: Blocked on MCP Server Integration with Dust

·Jul 31, 2025 11:48 AM·

🚨 Hey team – I’m completely blocked on integrating an MCP server with Dust, and need urgent help to unblock this for launch. *Issue:* When adding my MCP server in Dust (Spaces > Add MCP Server), I get:

SSE error: Invalid content type, expected "text/event-stream"

—even though all endpoints work in curl and return the correct headers. *What I’ve checked:* - /events returns Content-Type: text/event-stream (curl-verified) - / returns valid JSON-RPC - /.well-known/openid-configuration and /oauth-authorization-server are present and valid (with proper redirects/metadata) - All endpoints tested manually (curl/browser) work as expected - Dust is hitting /events (200), / (200), /tools/list (200), and /.well-known/openid-configuration (200) - Logs confirm correct behavior—no errors server-side *Minimal Repro:* - Deployed FastAPI server w/ all required endpoints *Request:* If anyone on the Dust eng or support team has seen this, or knows any gotchas (headers, handshake quirks, bugs) that might cause this error, please reply or DM ASAP. This is a *hard blocker* for our go-live and all help is massively appreciated. Happy to pair, screenshare, or provide full server logs if needed. Thank you 🙏 Sebastian