# Codex CLI as an MCP server: an MCP server we run in production

Canonical: https://scalably.io/mcp/codex-cli-mcp
Source: https://github.com/openai/codex
Registry: not published to the MCP registry
Provenance: third-party server, pinned at codex mcp-server, verified 2026-09-09. Verification note: codex mcp-server answers initialize correctly but prints 'codex mcp-server is deprecated and will be removed in a future release' on stderr (codex-cli 0.153.4); no replacement subcommand is documented yet, so the command stays as the install line
Integrity: no independent hash is published for this third-party listing; the raw endpoint at https://scalably.io/mcp/codex-cli-mcp.md mirrors this representation byte for byte
This is the machine-readable representation of the page at the canonical URL. Same facts, denser format.

## Direct answer
A second implementer and reviewer reachable as a tool from Claude Code.

## Install
- Claude Code: `claude mcp add codex -- codex mcp-server`
- Codex: not available for this server.
- Claude Desktop: not available for this server.

## Environment
No environment variables.

## Tools
No tools listed for this server.

## Setup
No environment variables required. Follow the vendor's own install instructions.

## Limits
Not documented by OpenAI. See the vendor's own documentation: https://github.com/openai/codex

## Reliability
- CI: not applicable, this is a third-party project we do not control.
- Pinned at codex mcp-server
- Verified 2026-09-09
- We run this server in production, pinned at the exact version, with the install command derived mechanically from that pin so it can be re-verified against the published package. codex mcp-server answers initialize correctly but prints 'codex mcp-server is deprecated and will be removed in a future release' on stderr (codex-cli 0.153.4); no replacement subcommand is documented yet, so the command stays as the install line

## Related
- Read more: [Codex skills: build reusable workflows that trigger](https://scalably.io/blog/codex-skills), [Claude Code MCP: how to add an MCP server](https://scalably.io/blog/claude-code-mcp)