Devin MCP connection not working

Hi ​@Dark Matter Lab 👋 Thanks for your post. Quick question before we dig in: how did you add the server in Devin? Are you using the Figma plugin from Devin's marketplace? https://docs.devin.ai/work-with-devin/mcp#figma 

Thank you! — Jaycee

Same here:

Hi,

Figma's MCP OAuth metadata advertises authorization_response_iss_parameter_supported: true, but the authorization response does not include the iss parameter. MCP clients that validate per RFC 9207 reject the callback, so the token exchange never happens.

Reproduce (step 1 needs no credentials):

curl -s https://api.figma.com/.well-known/oauth-authorization-server → "issuer": "https://api.figma.com", "authorization_response_iss_parameter_supported": true

Then run any RFC-9207-validating MCP client through the flow. The user approves in the browser, the redirect returns without iss, and the client aborts with: "Authorization response missing iss parameter advertised by the authorization server".

Identical metadata is served at both mcp.figma.com and api.figma.com (byte-identical).

Expected: either include iss=https://api.figma.com as advertised, or set the flag to false so clients skip the check. The former is correct per RFC 9207; the latter is a one-line unblock.

Impact: any RFC-9207-enforcing MCP client cannot connect at all. The consent screen succeeds and still yields no token, so it reads as user error rather than a server bug.

Distinct from forum topic 52978 (403-instead-of-401 before auth) — this one happens after approval.

Server-side fix; no client or account change helps.

Hi ​@MAD NICE AGENCY, thanks for flagging this! 

I understand how this must be disrupting your workflow. The metadata at api.figma.com does advertise authorization_response_iss_parameter_supported: true. I’ll flag the mismatch between that and the authorization response with our team. Two questions to make sure we've captured your case accurately:

• Which MCP client and version are you running, and are you pointed at mcp.figma.com or api.figma.com?
• Roughly when did you last attempt the flow? A recent timestamp helps us line your attempt up against what's deployed.

Let me know, and we’ll continue troubleshooting this together.

Same here. Trying to connect Figma with Hermes Agent via MCP oAuth yields in missing iss parameter.

URL is https://mcp.figma.com/mcp
Last tried: just now.