MCP Servers not exposed

Open 💬 4 comments Opened Aug 7, 2026 by cdaveygo

💡 Likely answer: A maintainer (github-actions[bot], contributor) responded on this thread — see the highlighted reply below.

What version of the Codex App are you using (From “About Codex” dialog)?

What subscription do you have?

Personal Pro Plan

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

I cannot access Custom MCP servers that had previously worked. I installed a new one and that one is not accessible either.

What steps can reproduce the bug?

Feedback ID: no-active-thread-019fdd26-ec70-7ac2-a211-0c6932bbb316

What is the expected behavior?

It should be able to list my Custom MCP servers that are correctly built as they remain connected and proper but it doesn't even list them. It only lists plugins that are from the marketplace that have been installed.

Additional information

_No response_

View original on GitHub ↗

4 Comments

github-actions[bot] contributor · 20 days ago

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

#37459

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cdaveygo · 20 days ago

While similar this has distinct differences than the others that were already there. This should be addressed separately as far as I can tell.

mlnima · 18 days ago

this is stupid, why when you can not make a right tool descovery release this without testing? I am giving it the exact name of mcp which was working before but stupid codex say I can not find it. you rename the mcp server and replaces all - to _ and added a mcp__ prefix, why? to save tokens? we are paying for this shit not you, I will cancel my sub if you do not fix it soon

westonwestenborg · 16 days ago

Cross-platform confirmation on macOS with the same Codex App build.

Feedback ID: 019ff2a3-9249-7751-92be-4d281a510218

Environment:

Codex Desktop 26.730.61639 (build 6234)
Bundled app-server 0.147.0-alpha.1.2
macOS 26.5.2 on Apple silicon
Direct MCP server: Lemlist at https://app.lemlist.com/mcp

The server is configured and enabled. After two full app restarts, fresh chats still receive no mcp__lemlist tools.

App-side evidence from the attached feedback logs:

The app-server handshake completes.
mcpServerStatus/list returns without an RPC error.
A fresh thread is then created, but filtering its actual tool inventory for lemlist returns [].
A direct Phoenix MCP server is present and callable in the same runtime, so direct MCP support is not failing as a whole.
The desktop log has no Lemlist authentication, initialization, or error event that would explain an action the user can take.

Expected: expose the enabled server's tools, or show a clear authentication or startup error. Actual: the server is silently omitted from the chat's callable tool inventory.

Lemlist worked in Codex Desktop before this build. The in-app feedback bundle includes the current session logs and the affected thread.