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Wake up to pull requests.

Each Night, Yellowhammer picks the next Feature from your spec and runs your own agent CLIs on it.

Download for MacView on GitHub
  • Requires macOS 26
  • Your code, credentials and models stay on your Mac.

The app

The Yellowhammer window showing the Pulse for one Project, idle between Nights. A sidebar lists the Project and its repository, the middle column shows five tiles and their cards, and an inspector on the right shows the repository's Repo Lane.
The Pulse, the main window's status view, for one Project between Nights. Screenshot of the app as it is today.
Close-up of the Pulse: the tiles Needs you, Now, Feature, Night and Health, above the Needs you card, which reads Nothing needs you, and the Now card, which shows no Attempt running.
Five tiles first: Needs you, Now, Feature, Night and Health. Then a card for each. Screenshot of the app as it is today.
Close-up of the Pulse: the Feature card with its one repository and pull request, the Tonight / last Night card marked done, and the Health card with no health flags.
The Feature in flight and its repositories, last Night's state, and the health flags. Screenshot of the app as it is today.
Close-up of the inspector for one repository: its Repo Lane with 3 of 3 cards done, its pull request, and the three Work Cards, each marked Done.
The inspector for one repository: its Repo Lane, its Work Cards and its pull request. Screenshot of the app as it is today.

What it never does

It never writes a line of code itself, and it never merges to main.

The agent CLIs write the code. Yellowhammer judges between them: it routes each Work Card, runs the checks, and verifies the result against your specification.

  • No code of its own

    Your agent CLIs write every line. Yellowhammer composes their instructions and reads their results.

  • No merge to main

    It hands off at the pull request, one per repository. The merge is yours.

  • No cloud execution

    Your code, credentials and models stay on your Mac. The Night runs on your existing subscriptions.

What you need

It sits on top of the tools you already use

Yellowhammer replaces none of them. You need a Mac on macOS 26 that stays awake through the Night, the Orca ADE, a Linear workspace, GitHub, and at least one supported agent CLI.

  • Worktrees

    Orca ADE

    Creates, places and cleans up a Worktree for each Feature and repository. Yellowhammer only holds its id and path.

  • The board

    Linear

    Intent comes from your Linear board, and every report goes back to it. In v1, the person running setup must be a workspace admin.

  • Pull requests

    GitHub

    Receives each Feature Branch and one pull request per repository. Yellowhammer writes to it and never merges.

Agent CLIs

The coding agents you already use in the terminal. They write the code. Each Work Card runs on a route: one agent CLI, one model and one effort level.

  • Claude Code

    claude

    Probed for unattended runs.

  • Codex

    codex

    Probed for unattended runs.

Adding another agent CLI takes an adapter and a probe, not a configuration edit.

How it works

One Night, in three Acts

A Night is one overnight run for one Project. It runs in three Acts, author, build and land, each started on a schedule by macOS. You read the result in the morning.

  1. author

    It picks the work

    It selects one Feature from your specification and works out which repositories it touches. It writes the Work Cards, each with a Definition of Done written before any code exists. It does this even when the board is empty.

  2. build

    Your agents write the code

    Each Work Card goes to an agent CLI and runs in a Worktree, one Repo Lane per repository. The engine runs each repository's check itself. A failed try goes to a different model, then stops at limits you set.

  3. land

    One pull request per repository

    It pushes each Feature Branch and opens one pull request per repository. A different agent verifies the Feature clause by clause against its Definition of Done. The merge stays yours.

  4. Night Summary

    You read the verdict

    The Night Summary on your board says what landed, what is blocked and what needs you. A Work Card that needs an answer goes to Waiting on You, and you answer it in Linear.