co mcp

Experimental. Built on Codex's app-server protocol, which Codex itself marks experimental.

Call the MCP servers and account connectors you already have in Codex (Gmail, Google Calendar, GitHub, Vercel, your own servers) from the terminal, with no second login and no model turn. Codex holds every credential; co starts codex app-server, opens a throwaway session that never reaches your Codex history, and asks it to run one tool.

co mcp ls                                   # servers, tool counts, auth state
co mcp tools codex_apps                     # one line per tool; read-only ones are marked
co mcp call codex_apps gmail.search_emails '{"query": "newer_than:7d"}'

codex_apps is the server behind the connectors you enabled in Codex or ChatGPT. A server you added with codex mcp add appears under its own name.

Reading and acting

Each tool says whether it only reads (readOnlyHint). A read-only tool runs at once and prints its own data as JSON, unchanged. Any other tool — send an email, create an issue, delete messages — prints what it would do and runs only with --yes:

co mcp call codex_apps gmail.send_email '{"to": ["bo@example.com"], "subject": "Deck", "body": "Attached."}'
co mcp call codex_apps gmail.send_email '{"to": ["bo@example.com"], "subject": "Deck", "body": "Attached."}' --yes

What it needs

• codex on PATH, logged in (codex login). Connectors are enabled in Codex or ChatGPT; co does not add or log in to any.
• Nothing from Claude Code. Its claude.ai connectors (Gmail, Drive, Calendar) are reachable only through a Claude turn (claude -p --allowedTools mcp__claude_ai_Gmail__search_threads …), which costs a model call; co mcp does not call them.

Measured

On one Mac, 2026-10-11 (codex-cli 0.162.1): codex_apps listed 537 tools, gmail.get_profile answered in 3.2 s and gmail.search_emails in 1.3 s, with message and thread ids in the result. The same Gmail search through claude -p on Haiku 4.5 took 12.2 s and $0.044.

Errors

You see	Do
Codex is not installed	npm install -g @openai/codex && codex login
Codex has no MCP server named X	co mcp ls
X has no tool named Y	co mcp tools X
a server shows notLoggedIn	codex mcp login <server>