firstmate

Talk to one agent. Ship with a crew.

What it is

You can run one coding agent easily. But the moment you want three project tasks done in parallel - fixes, investigations, plans, audits - you become a tab-juggler: babysitting sessions, copy-pasting context between repos, forgetting which terminal had the failing test.

firstmate flips the model. You talk to a single agent - the first mate - and it runs the crew for you: spawning autonomous agents in tmux windows, giving each a clean git worktree, supervising them to completion, and handing you finished PRs, approved local merges, or standalone investigation reports. For larger fleets, you can opt in to persistent secondmates: domain supervisors that are still ordinary direct reports, but run from their own isolated firstmate homes. There is no app to install; the orchestrator is AGENTS.md, bundled skills, and helper scripts that any terminal coding agent can follow.

This is not an agent harness. This is not a single skill. This is not a CLI. This is.. a directory that turns any agent into your firstmate, and you the captain.

Features

• One liaison - you talk only to the first mate; it dispatches, supervises, escalates only real decisions, and reports plain outcomes.
• A visible crew - every crewmate works in its own tmux window you can watch or type into; the first mate reconciles.
• Disposable worktrees - each task runs in a clean treehouse git worktree, so parallel work on one repo never collides.
• Two task shapes - ship tasks deliver a change; scout tasks investigate, plan, reproduce, or audit and leave a report.
• Explicit project modes - each project ships via no-mistakes, direct-PR, or local-only, with an optional +yolo autonomy flag.
• Optional secondmates - opt in to persistent domain supervisors that run from isolated firstmate homes with their own FM_HOME, state, projects, and session lock, kept on the primary firstmate version by guarded local fast-forwards.
• Event-driven, zero-token supervision - a bash watcher sleeps on the fleet and wakes the first mate only when something needs you.
• Guarded by construction - the first mate is read-only over your projects outside clean default-branch refreshes, safe branch pruning, and approved local-only fast-forward merges; crewmates make every project change behind your merge approval.
• Restart-proof - all state lives on disk and in tmux; kill the session anytime and the next one reconciles and carries on.

Full detail on every feature lives in docs/architecture.md.

Quick Start

Requirements: a verified agent harness (claude, codex, opencode, or pi), git with GitHub auth, and tmux for the crew windows. The first mate detects and offers to install everything else.

gh auth login
git clone https://github.com/kunchenguid/firstmate
cd firstmate && claude   # launch your harness here; AGENTS.md takes over

Then just talk:

> ahoy! look at my github project xyz, then fix the flaky login test and add dark mode

# firstmate checks its toolchain (asking your consent before installing anything),
# clones the project under projects/, and spawns two crewmates in tmux windows
# fm-fix-login-k3 and fm-dark-mode-p7.
# Minutes later:

  PR ready for review, captain: https://github.com/you/xyz/pull/42
  (fix flaky login test - risk: low - CI green)

> alright merge it

Run it inside tmux for the best experience: launching your harness from inside tmux puts every crewmate window in your own session, where you can watch the crew work in real time or type into any window to intervene. Outside tmux, crewmates land in a detached firstmate session you can attach to.

How It Works

            you (the captain)
                  │  chat: requests, decisions, "merge it"
                  ▼
 ┌─────────────────────────────────────┐
 │ firstmate            (this repo)    │
 │ reads projects/ + firstmate routes  │
 │ writes guarded backlog/briefs/state │
 └──┬──────────────┬───────────────┬───┘
    │ tmux send-keys / status files │
    ▼              ▼               ▼
 ┌────────┐   ┌────────┐      ┌────────┐
 │fm-task1│   │fm-task2│  ... │fm-taskN│   tmux windows you can watch
 │crewmate│   │crewmate│      │crewmate│   one autonomous agent each
 └───┬────┘   └───┬────┘      └───┬────┘
     ▼            ▼               ▼
  treehouse worktree or isolated secondmate home
     │
     ├─ ship: project mode ► PR/local merge ► teardown
     │
     └─ scout: report at data/<id>/report.md ► relay findings ► teardown

You chat with the first mate. It routes each request to a crewmate in its own tmux window and git worktree, supervises the fleet with a zero-token event-driven watcher, and brings you finished PRs, approved local merges, or investigation reports. Persistent secondmate homes are linked firstmate worktrees; startup syncs live ones and secondmate launch syncs the target home to the primary default-branch commit without fetching from origin when it is safe. When a routed request goes to a secondmate, firstmate marks it so the answer returns through status or a document pointer; direct typing into that secondmate window stays conversational. A presence-gated sub-supervisor (/afk) can self-handle routine events and batch only what matters while you step away. When firstmate works on itself, spawn-time isolation checks and a primary-checkout tangle alarm keep the operating checkout on its default branch and stop a crewmate that did not land in a separate worktree.

Full architecture - the supervision engine, worktree isolation, secondmates, project modes, fleet sync, and self-update - is in docs/architecture.md.

Built-in skills

Firstmate ships these user-invocable built-in skills. Claude uses the slash form shown here; codex uses the same names with $, such as $afk.

Skill	What it does
/afk	Enter away-mode supervision: the sub-supervisor self-handles routine wakes in bash and escalates only captain-relevant events as one batched digest, cutting supervision cost while you step away
/updatefirstmate	Self-update the running firstmate and its secondmates to the latest from origin with fast-forward-only pulls, then re-read instructions and nudge secondmates

Agent-only reference skills live under .agents/skills/ and are loaded by firstmate at the trigger points named in AGENTS.md.

Documentation

• docs/architecture.md - how the crew, supervision, worktrees, secondmates, and project modes work.
• docs/configuration.md - environment variables, FM_HOME, the files you set, and harness support.
• docs/scripts.md - the bin/ toolbelt reference.
• AGENTS.md - firstmate's full operating manual for the orchestrator agent.
• CONTRIBUTING.md - how to contribute, including the dev/test commands.

Contributing

Contributions are welcome - see CONTRIBUTING.md for the workflow, repo conventions, and how to run the tests.

License

MIT - see LICENSE.