---
title: "Codex"
description: "Give Codex a window into your running app through the Loggerhead MCP server."
source: "https://getloggerhead.com/docs/connect-your-ai-tool/codex/"
---

# Codex

> Give Codex a window into your running app through the Loggerhead MCP server.

Loggerhead ships an MCP server. Its tools let your coding tool read your logs, metrics, traces, and lint findings, mark a finding fixed, and change the lint rules with a reason that you can undo in the app. The server talks to the Loggerhead engine on your Mac over `127.0.0.1`. Nothing leaves the machine.

## Add it with one click

1. Open Loggerhead and click **Settings** in the sidebar.
2. Open the **AI** tab.
3. In the **AI coding tools** card, click **Add** next to **Codex**.

Loggerhead writes the server into `~/.codex/config.toml` and keeps every other entry in that file. It leaves a copy of the previous file beside it with the extension `.bak`. Restart Codex, and the Loggerhead tools appear.

The server finds the engine by itself. You do not set a port, and the entry survives a restart.

## Add it by hand

Add this block to `~/.codex/config.toml`.

```toml title="~/.codex/config.toml"
[mcp_servers.loggerhead]
command = "/Applications/Loggerhead.app/Contents/Resources/loggerhead-mcp"
args = []
```

Restart Codex. The tools appear under `loggerhead`.

## Try it

Ask Codex to find the slowest trace in the last hour. It calls `query_traces` with a minimum duration and reads the spans.

To send the project's own logs, metrics, and traces to Loggerhead, paste the prompt from [Connect your project with one prompt](/docs/connect-your-ai-tool/connect-your-project-with-one-prompt/).

See [Tools reference](/docs/mcp-server/tools-reference/) for what each tool accepts.