Ask Codex
Let Claude call OpenAI Codex CLI for collaboration, review, and a different model’s take on your code.
Overview
io.github.Lykhoyda/ask-codex is a MCP server for the Ship phase that connects your agent to the OpenAI Codex CLI for AI-to-AI collaboration and code review over stdio.
What is this MCP server?
- Stdio MCP via npm package ask-codex-mcp (version 0.3.9)
- Routes prompts to OpenAI Codex CLI for collaboration and code review
- GMCPT_TIMEOUT_MS default 300000 ms for long Codex runs
- GMCPT_LOG_LEVEL controls debug through error logging
- Part of the Lykhoyda ask-llm family on GitHub
- Server version 0.3.9
- Package identifier ask-codex-mcp on npm
- Default GMCPT_TIMEOUT_MS 300000
Community signal: 10 GitHub stars.
What problem does it solve?
Switching between Claude and Codex manually breaks flow and loses thread context when you only wanted a quick cross-model review.
Who is it for?
Builders who run both Claude Code and Codex CLI and want MCP-native handoffs for reviews or paired problem-solving.
Skip if: Users without OpenAI Codex CLI setup, or teams that forbid subprocess calls to external AI CLIs from the dev machine.
What do I get? / Deliverables
With ask-codex-mcp registered, your agent can invoke Codex CLI tasks and fold responses back into the same MCP conversation.
- MCP-accessible Codex CLI invocations from your primary agent
- Configurable execution ceiling via GMCPT_TIMEOUT_MS
- Observable runs through GMCPT_LOG_LEVEL
Recommended MCP Servers
Journey fit
How it compares
MCP integration to Codex CLI, not the Codex product UI alone or a static review skill.
Common Questions / FAQ
Who is io.github.Lykhoyda/ask-codex for?
Developers using MCP agents who already have OpenAI Codex CLI installed and want Claude (or Cursor) to call it programmatically.
When should I use io.github.Lykhoyda/ask-codex?
Use it before merge or release when you want Codex to challenge Claude’s patch, or during Build when two agents should iterate on a design.
How do I add io.github.Lykhoyda/ask-codex to my agent?
Add ask-codex-mcp as a stdio MCP server in your client config, install dependencies via npm, authenticate Codex CLI separately, and optionally set GMCPT_TIMEOUT_MS and GMCPT_LOG_LEVEL.