Caduceus

What Caduceus does

Caduceus is a single Rust binary that does two jobs. It runs each new revision of an open pull request through an isolated, read-only review worker and publishes a structured PASS or FAIL verdict, with findings, severities and remediation guidance, as one sticky comment that is updated in place. It also takes tickets labeled autofix, provisions a fresh worktree, runs your AI harness under a hard timeout, then commits, pushes, opens a pull request, comments and closes the ticket, checkpointing each step before it happens so a crash resumes instead of double-posting.

The daemon owns polling, claims, worktrees, timeouts, Git, GitHub and retries, while the worker only decides what the code should say. The two meet through environment variables and a worker-result.json file. A reference bridge, worker-bridge.py, is seeded under ~/.hermes/caduceus/ for you to point at pi, codex, claude-code or a custom harness, and plugin updates will not overwrite it. The daemon is pull-only, listens on no port and refuses to publish text containing a hardcoded list of internal tool names. Linux is tier-1 and macOS tier-2.

Key features

• Sticky PASS or FAIL pull request review comment, updated in place as the PR changes
• Trusted /caduceus review comment to re-review the current head on demand
• Issues labeled autofix become a worktree, commit, PR, comment and close
• Checkpoints before every step so a crash resumes without double-posting
• Pull-only daemon with ETag-aware polling that listens on no port
• Harness-agnostic worker-bridge.py that you own and edit

When to use it

• Getting an automated first review on every revision of a pull request
• Delegating labeled handoff tickets to an AI harness and reviewing the PRs it opens
• Running the agent loop on your own machine with your own credentials

Who it is for: Developers who run AI coding harnesses and want a self-hosted daemon to handle PR review and ticket-to-PR work on their own repositories.

How it fits with Hermes Agent

Shipped as a Hermes plugin with its bridge seeded under ~/.hermes/caduceus/; the worker harness behind it can be pi, codex, claude-code or your own.

Requirements: Linux (tier-1) or macOS (tier-2), a Windows target is not supported, and a worker harness reachable through worker-bridge.py

FAQ