Use the codex MCP tools to delegate tasks to OpenAI Codex CLI.
Prerequisites
Codex must be installed and signed in:
npm i -g @openai/codex
# sign in via the Codex app — no API key needed
Synchronous delegation (need result now)
Use codex_run when you need the output before continuing:
codex_run(
prompt="<full task description with all context Codex needs>",
cwd="/path/to/project" # optional, defaults to current directory
)
Returns the final Codex message as a string.
Background delegation (parallel work)
Use codex_task_submit to fire off tasks and continue working:
-
Submit one or more tasks:
codex_task_submit(name="Refactor auth module", prompt="...", cwd="...") codex_task_submit(name="Write tests for API", prompt="...", cwd="...") -
Check status:
codex_task_status(task_id="<id>") -
Fetch result when completed:
codex_task_result(task_id="<id>") -
See all tasks:
codex_tasks_list()
Environment variables
| Variable | Purpose |
|---|---|
CODEX_PATH | Override path to the codex binary |
CODEX_SANDBOX | read-only, workspace-write, or danger-full-access — if unset, uses --dangerously-bypass-approvals-and-sandbox for headless operation |
Writing good prompts for Codex
- Include full context — Codex starts fresh with no knowledge of prior work
- Specify the working directory if the task involves files
- Be explicit about what "done" looks like (files to edit, tests to pass, output expected)
- If the task spans multiple files, list the key ones