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Firstmate: talk to one agent, ship with a crew.

You talk to a single agent, the first mate, and it runs the crew for you: it gives each task its own agent in a clean git worktree, supervises them to the end, and hands you finished pull requests, approved local merges or investigation reports.

Run it kunchenguid/firstmate

Firstmate is created by Kun Chen (more from Kun Chen ): kunchenguid/firstmate, MIT licence. Wheelhouse and Fleetyard are built on top of Firstmate.

Not an app or a model: a folder of instructions, skills and scripts that any terminal coding agent can follow. Clone it, start your agent inside it, and you are the captain.

Play “L8 Principal Building a Full Stack App with Agentic Engineering”
“L8 Principal Building a Full Stack App with Agentic Engineering”, from Kun Chen on YouTube.

The architecture

One supervisor, a crew in their own worktrees, a validation pipeline on every change, and a toolbelt built for agents.

How Firstmate works You, the captain, talk to one agent, Firstmate, from Wheelhouse, a terminal or your phone. Firstmate supervises: it hands each task to a crewmate with its own agent session in its own treehouse worktree, and a watcher wakes it only when something changes. Each crewmate's work goes through the no-mistakes pipeline, review, tests, lint, docs, push, pull request and CI, to a pull request with green checks for you to merge. Second mates are Firstmates with homes of their own. The -axi CLIs, gh-axi, tasks-axi, quota-axi, chrome-devtools-axi and lavish-axi, are the toolbelt Firstmate and its crew use. You, the captainrequests, decisions, “merge it” Wheelhouse, a terminal or your phone Firstmate, the supervisorOne agent you talk to. It dispatches, supervises andasks you only the real decisions. watcher wakes it on change state on disk: restart-proof Crewmate 1its own agent treehouse worktree Crewmate 2its own agent treehouse worktree Crewmate 3its own agent treehouse worktree no-mistakesreview · tests · lint · docs · push · pull request · CI Pull request, checks greenready for you to merge The -axi CLIs gh-axitasks-axiquota-axichrome-devtools-axilavish-axi Second matesFirstmates with their own home,here or on another machine

The supervisor

Firstmate is the one session you talk to: the captain and crew model. It turns a request into tasks, starts a crewmate for each in a visible terminal you can watch (tmux by default, or Herdr and others), and supervises them to the end.

  • Escalates only real decisions; answers the rest itself and reports plain outcomes.
  • A watcher sleeps on the fleet and wakes it only when something changes, so supervision costs no tokens while nothing happens.
  • Everything lives on disk, so a restarted session reconciles and carries on.
  • Second mates: Firstmates with homes of their own, on this machine or another, that report to it.

treehouse

Each task gets a clean, pre-warmed git worktree from a pool, so several agents work on one repository in parallel without colliding, and your own clone is never touched.

kunchenguid/treehouse

no-mistakes

A local git proxy that validates a change before it reaches the pull request: review, tests, lint and docs, then the push, the pull request and its CI checks. Findings are fixed in rounds; anything that needs a person comes to you as a decision.

Each project chooses its mode: through no-mistakes, a direct pull request, or local merges only.

kunchenguid/no-mistakes

The -axi CLIs

Command-line tools built for agents (AXI, the Agent eXperience Interface): compact output, suggestions for the next step and changes that are safe to repeat.

gh-axi
GitHub for agents: pull requests, checks, issues and releases in compact output, with idempotent changes.
tasks-axi
The backlog: the tasks Firstmate queues, starts, blocks and finishes, kept as files it can reread after a restart.
quota-axi
How much of each agent’s allowance is left, so Firstmate picks which agent takes the next task.
chrome-devtools-axi
A real browser: open the app under review, click through it, read the page and take screenshots.
lavish-axi
Rich review pages for decisions and reports, where you mark up what you mean and send it back.

Run it

Sign in to GitHub, clone Firstmate and start your agent inside it. The README covers setup for every agent and terminal backend, and the full architecture.

Firstmate is created by Kun Chen (more from Kun Chen ): kunchenguid/firstmate, MIT licence. Wheelhouse and Fleetyard are built on top of Firstmate.

Read it on GitHub

gh auth login
git clone https://github.com/kunchenguid/firstmate.git
cd firstmate && claude

Or Codex, Pi, Grok, OpenCode and more. It checks its own tools and asks before installing any.