Prepcook

Prepcook

A prep cook does the prep so the chef can cook.

Prepcook does the prep on a bug — reproduces it, explains it, fixes it, reviews the fix, opens the pull request — and the engineer who owns the ticket signs off. Each ticket is a card on a local board, each stage of the card is worked by a coding agent in its own git worktree, and when a person takes the ticket over, Prepcook steps aside.

Get started GitHub
The Pantry board in Prepcook: cards in To Do, Plan (a bug waiting at the gate and a triaged investigation), Execute, Review and Shipped (merged)
The Pantry board in Prepcook: cards in To Do, Plan (a bug waiting at the gate and a triaged investigation), Execute, Review and Shipped (merged)

The board

How a card moves

A card moves through five stages, left to right across the board.

  1. 1

    Plan

    Reproduce it, then explain it

    Prepcook stands the app up in the card's worktree and an agent reproduces the bug first, with a harness that fails for the reported reason. Only then does it write the root-cause analysis (RCA): what happens, why, and how sure it is. A person approves it, asks for changes, or sends it back.

  2. 2

    Execute

    The smallest fix, with tests

    A new session makes the smallest fix for the mechanism the RCA isolated and keeps at it until the reproduction passes, adding regression tests. It commits on a branch rebased onto the target branch and does not push.

  3. 3

    Review

    Fresh eyes on the fix

    A separate agent reviews the change in a fresh worktree, with the diff, the code around it and the reproduction, and none of the planning context. When it asks for changes, its findings go back to the implementing agent to fix or rebut, for up to three rounds.

  4. 4

    Shipped

    PR open or merged; you clean up

    Prepcook pushes the branch and opens the pull request (GitHub) or merge request (GitLab), then feeds review comments on it back to the implementing agent. The card shows the pull request's state — open, CI failing, merged, closed without merging — and once it merges, the ticket is closed and the card waits for you to clean it up.

  5. 5

    Clean up

    Worktrees archived

    Prepcook runs the repository's clean-up script and archives the card's worktrees. Clean up never takes a card whose pull request is still open. Every approved RCA stays in a knowledge store, linked into a graph of root causes, so a cause that keeps coming back becomes visible and opens a pattern review of its own.

The method

What makes it different

Reproduce first

A bug card's Plan stage makes the failure happen, and only then explains it. The planning agent is told not to read code for the cause until it has a script that fails for the reported reason.

Reproduce first

The RCA and the knowledge graph

Every bug RCA goes into a knowledge store, linked into a graph of product areas, components and root-cause classes, so a cause that keeps coming back becomes visible and opens a pattern review of its own.

The knowledge store and the graph

Fresh-eyes review

A separate agent reviews the change in a fresh worktree, with the diff, the code around it and the reproduction, and none of the planning context. Its findings go back to the implementing agent for up to three rounds.

The independent review

Works alongside people

In Chef mode it works your tickets and you move the cards and approve each plan; in Prep mode it works on its own. An engineer who assigns a ticket to themselves takes it over, and Prepcook steps aside.

Working alongside people

Investigations and incidents

An investigation card runs Plan exactly as a bug does, then posts a triage report and stops until a person converts it to a bug or closes it. In incidents mode, each open incident becomes one, and the report goes back to the incident as a note.

Investigations Incidents

Integrations as factories

Notifications, ticketing, reproduction, evidence and agents are each configured under Settings → Integrations, rendered from what each provider says about itself, with a Test connection button per provider.

Configuration The settings screens

Screens

A look around

The Plan card ("Sharing a list fails for a user who exists") open, its REPRODUCTION: comment and the RCA comment in view.
The Plan card ("Sharing a list fails for a user who exists") open, its REPRODUCTION: comment and the RCA comment in view.
The triaged investigation in Plan open, its amber Needs you header ("Triaged — report ready", Close) and its TRIAGE REPORT in view.
The triaged investigation in Plan open, its amber Needs you header ("Triaged — report ready", Close) and its TRIAGE REPORT in view.
Settings → Integrations → Notifications, with one webhook target.
Settings → Integrations → Notifications, with one webhook target.
Settings → Integrations → Agents.
Settings → Integrations → Agents.
The Scripts card after Test stand-up: outcome ok, the setup, start, ready and seed steps at exit code 0.
The Scripts card after Test stand-up: outcome ok, the setup, start, ready and seed steps at exit code 0.

The Slack agent

Tammy

If Prepcook is the prep cook, Tammy is the waitress. When a customer reports something that looks broken, she takes the order to the kitchen: she asks the questions an engineer would ask, files an investigation card on Prepcook, waits for its triage report, and explains it to the customer in plain English.

Meet Tammy

Install

Three ways in

With npx

Node is already a prerequisite, so this is the quickest route: the package downloads the release binaries for your platform on first run and keeps them in ~/.prepcook/bin (npx-cli/README.md).

sh
npx prepcook up

From a release

Fetch the tarball for your platform with curl, check it against SHA256SUMS, and put prepcook and prepcook-mcp in ~/.local/bin, which must be on your PATH:

sh
v=0.1.0 t=macos-arm64   # or macos-x64, linux-x64
curl -fsSLO "https://github.com/nwisehart/prepcook/releases/download/v$v/prepcook-$v-$t.tar.gz"
curl -fsSL "https://github.com/nwisehart/prepcook/releases/download/v$v/SHA256SUMS" | grep " prepcook-$v-$t.tar.gz$" | shasum -a 256 -c -
tar -xzf "prepcook-$v-$t.tar.gz"
mkdir -p ~/.local/bin
install -m 755 "prepcook-$v-$t"/prepcook "prepcook-$v-$t"/prepcook-mcp ~/.local/bin/
prepcook up

Downloaded from the releases page in a browser instead, the binaries are quarantined and, since they are not notarized, macOS blocks the first run; clear it with xattr -d com.apple.quarantine on both.

The board image

prepcook up runs the board from the published image ghcr.io/nwisehart/prepcook-board:<version>, the version of the prepcook binary that starts it; there is nothing to pull by hand. To run the board elsewhere, see crates/remote/README.md; to build from a checkout, see Build, run and test.

Then follow the Quickstart: a bug from report to pull request on Pantry, the demo app.