Agenda MCP not connecting on Claude Desktop for Mac

Support
1

What I did: Started the latest version of Claude Desktop for Mac on MacOS 27 (this issue has been around in MacOS 26 as well). I disabled and re-enabled the Agenda Connector. No change; still unable to connect. I reinstalled the Agenda connector. No change; still unable to connect. I restarted machine; no change still unable to connect.

What happened: Claude shows this error message: MCP Agenda: Couldn’t start for Cowork and Code sessions. Error: Agenda is not reachable. Connection refused. Please open Agenda and enable the MCP server via Agenda > Integrations > Enable MCP. AGENDA_MCP_PORT=16106

What I expected: Claude to be able to connect to Agenda. Instead connection is unable to be established.

Things that might be helpful to know (Agenda version, OS and model, etc): Agenda Version 23.3.2 (425); MacOS 27.0; Claude 2.2553.1 (c38127) 2026-09-18T00:41:58.000Z

2

Happened to me too. I realized that Agenda has to be open before Claude. Hope this helps.

3

Oh, fantastic! That fixed it! For some reason, I always started Claude first and never put two and two together. Starting Agenda first and then starting Claude fixed the issue.

Thank you!

4

I think you might be able to use the /mcp command in Claude to refresh the connection once Agenda is launched. Not 100% sure.

5

I’m glad you figured it out. I was coming here to say to start Agenda first. I have to mention that having Claude integrated with Agenda, Tinderbox, DEVONthink, Calendar 366, and Curio has been a game changer for me; I’m amazed at what it can do and the time it saves. If only I would quit playing with all of it and focus on grading all these doggone discussion boards.