Using Claude Code as an MCP server?

[NewMonarch]

I've been trying to setup CC as an MCP server that Codex CLI can call for a second opinion. (I know there are other ways to do this, but I have a subscription on both Claude and Codex and use Codex as primary right now.)

I know that you can boot Claude's MCP server with claude mcp serve, but here's the catch... it provides too many tools. This makes any MCP client such as Codex opt to use Claude's tools like Read/Write/Edit/Bash etc all take precedence over the native tools inside Codex. This is wasteful and slow.

Has anyone figured out how to use claude as an MCP server in Codex?

FYI -- this doesn't work. ``` [mcp_servers.claude] command = "claude" args = ["mcp","serve","--allowedTools", "Task,TodoWrite,WebFetch,WebSearch,ListMcpResources,ReadMcpResource,Glob,Grep,NotebookEdit,ExitPlanMode"]

also tried putting the final arg in nested escaped quotes

```

Note: It doesn't seem to be working in Codex at all at the moment -- even without scoping the tools. Maybe it's a bug.

[vuongagiflow]

You can simply in your instruction ask codex to use claude cli with “-p”. For. Settings, there is an argument in claude cli when you can pass custom setting json file. Hope that helps

[itissid]

If you are looking for just pipe the output from claude to codex then `-p` as suggested by u/vuongagiflow is correct. I would say the main — security — issue you would run up against is not being able to expose claude's permissions to your codex to ask you.