Codex

Loggerhead ships an MCP server. It gives your coding tool five read-only tools: search logs, query metrics, search traces, get one trace, and get the receiver addresses. 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 Collectors in the sidebar.
2. Select Local OTLP receiver.
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.

~/.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.

See Tools reference for what each tool accepts.