Zimmer

Zimmer is open-source, standards-built, and made for a single circle of trust — you, or a couple, or business partners. You stay in control of what runs and what merges; Zimmer handles the toil of getting an agent from a prompt to a verified PR.

What it does

It runs a real agent, headless

A session is a real Claude Code or Codex process running against a real clone of a real repo. It commits, it pushes, it opens a PR, and it hands the result back for you to approve.

It has a lifecycle

waiting → running → needs_input → archived. Every session sits in one of those states, and the state machine decides the next move, not a human babysitting a terminal.

It wires the context

Skills, MCP servers, agent roots, hooks, plugins, and references are resolved from a catalog by AIR and injected into the clone before the agent starts.

It tells you what's broken

These docs include a Known limitations page that names real bugs in real files. It is meant to be read, not skipped.

These docs are blunt on purpose

The premise is that you can read this site instead of the code. That only works if it tells you what the code would, so it names Zimmer’s real bugs and limitations — inline where they bite, and aggregated on Known limitations. Where the code and the old docs disagreed, the code wins and the contradiction is written down. Where the code was genuinely ambiguous, you get an “unclear — needs confirmation” note instead of a guess.

Where to go next

PhilosophyThe opinions baked into Zimmer: isolated clones, closed-loop autonomy, MCP as a blast radius, PR-as-review-gate, and why the catalog exists.

ArchitectureRails app, GoodJob workers, agent subprocesses, Postgres, Redis, and the diagram of how a prompt becomes a running process.

Run it locallyPrerequisites, setup, and the environment variables that actually matter.

AIRThe separate open-source project that resolves an agent's context from a catalog. This is the canonical write-up.

REST APIEvery endpoint, re-derived from the routes, including the six resources the old reference forgot.

Known limitationsThe bugs, the brittleness, and the things nobody has decided yet. Read this before you trust anything else.