Harness Source Map

What the agent harness puts in front of the model.

Every prompt, reminder, tool description and setting that Claude Code and Codex/ChatGPT send, read from the shipped binaries, each with its source.

Which harness?

Trace a session

Open your own Claude Code or Codex/ChatGPT session log and see what reached the model, where it came from, and who got it. Runs in your browser; nothing is uploaded.

Open Trace