Detected signals
Agent markers found in commit metadata. Unsigned, and never proof.
Many agents leave a marker in the commits they make, such as a co-author trailer or a bot author. Euthyne reads these markers from the forge and shows them as detected signals.
Detected signals are unsigned. They are never proof.
Where they come from
When the GitHub App is installed, Euthyne reads recent merged pull requests and their commits, and looks for known markers. After that, it checks every new merge the same way.
This gives a first picture before anyone installs the CLI. It also produces the strongest flag Euthyne has: a merge that carries an agent marker but has no receipts.
Euthyne stores the parsed marker, never the commit message.
Why they are not proof
- A marker can be removed, edited or typed by hand.
- No marker means nothing. Some tools add none by default, and most local markers can be turned off.
So Euthyne may say: "12 merged pull requests carry an agent marker in their commit metadata. Detected, not signed."
It never says that those pull requests were written by agents, gives a share of AI-written code, or implies that unmarked work is human.
How they are shown
- A grey Detected label, never the seal.
- They never count toward coverage, any trust level or Full proof.
- Change receipts list them as observed markers.
Known markers
Euthyne matches trailers without regard to case, and matches author name and email, not the forge login.
| Agent | Marker |
|---|---|
| Claude Code | Co-Authored-By: <model> <noreply@anthropic.com> trailer |
| Claude Code GitHub Action | Commits by claude[bot] |
| GitHub Copilot coding agent | Commits by copilot-swe-agent[bot], Agent-Logs-Url: trailer |
| GitHub Copilot CLI and VS Code | Co-authored-by: Copilot trailer |
| Codex CLI | Co-authored-by: Codex <noreply@openai.com> trailer |
| Codex cloud | Commits by Codex <codex@openai.com> (observed) |
| Cursor | Pull requests by cursor[bot], Co-authored-by: Cursor trailer |
| Aider, Jules, Devin, Amp | Co-author trailers or bot authors |
Tools change their markers. This list reflects what we checked in October 2026.