Codex Desktop starts configured MCP server successfully, but does not expose its tools to the model

[bnfaf]

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

版本26.422.62136 (2180)

What subscription do you have?

ChatGPT team

What platform is your computer?

Darwin 24.1.0 arm64 arm

What issue are you seeing?

I configured an MCP server in ~/.codex/config.toml. Codex Desktop starts the MCP server successfully, and the MCP server logs show that its tools were registered successfully.

However, the tools are not exposed to the model inside the Codex Desktop thread.

The MCP log under ~/.mcp/data/ shows:

Registering MCP tools...
All tools registered successfully
MCP server started successfully and ready to process requests

But inside the Codex Desktop thread:

• tool_search for Confluence, Atlassian, wiki, or get_page returns no Confluence MCP tools.
• No mcp__shopee_confluence__search or mcp__shopee_confluence__get_page namespace is available.
• list_mcp_resources returns an empty list.
• The assistant cannot call the configured MCP tools, even though the server was started and registered tools successfully.

Expected behavior:
If Codex Desktop starts an MCP server and the server registers tools successfully, those tools should be exposed in the model’s available tool manifest for that thread.

Actual behavior:
The MCP server starts successfully, but its tools are not exposed to the model. This makes the MCP unusable from the assistant despite successful initialization.

Impact:
The user believes the configured MCP is available, but the assistant cannot call it. There is no clear error indicating that the tools were filtered, hidden, or not injected into the model context.

What steps can reproduce the bug?

1. Configure an MCP server in ~/.codex/config.toml, for example a stdio MCP server with tools enabled.

2. Start Codex Desktop and open a local workspace/thread.

3. Confirm that the MCP server started successfully by checking ~/.mcp/data/mcp-server.*.log.

The log shows:

Registering MCP tools...
All tools registered successfully
MCP server started successfully and ready to process requests

4. In the Codex Desktop thread, ask the assistant to use or search for the MCP tools, for example:

• Use the Confluence MCP to read this page.
• Search available tools for Confluence / Atlassian / get_page.

5. Observe that the assistant cannot access the MCP tools:

• tool_search does not return the configured MCP tools.
• No mcp__...__search or mcp__...__get_page tool namespace is available.
• list_mcp_resources returns an empty list.

What is the expected behavior?

No response

Additional information

No response

[github-actions]

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

• Codex bug: MCP servers load successfully but their tools aren't exposed to the model #20771
• Newly configured stdio MCP server is enabled but absent from assistant tool manifest #21406
• Codex App shows MCP servers enabled, but current session only receives a subset of MCP tools #21654
• MCP servers from config.toml do not work anymore #21789

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[bnfaf]

Closing as duplicate of #21654. My case is the same: the MCP server starts successfully and registers tools, but the tools are not exposed to the model in the current Codex Desktop session.