PI Review

Review, accept, or revert code changes made by the PI agent — right from your browser.

PI Review is a PI extension that tracks every file the agent edits, creates, or deletes. It gives you a clean web interface to see what changed, leave line-level comments, accept the good changes, and revert the ones you don't want.

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The Problem

When an AI coding agent modifies your code, it happens fast — files change, new code appears, and you're left wondering "what did it just do?" The agent's chat history shows tool calls, but it's hard to get a clear picture of every file change across multiple edits.

PI Review solves this by:

• Tracking every edit the agent makes (through edit, write, or bash tools)
• Showing a unified diff per file — so you see all changes together, not scattered across tool calls
• Letting you accept or revert changes, one file at a time or all at once
• Preserving a history of every accept/revert action, so you can go back and review what was done

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Main Workflow

1. The agent makes changes

When the PI agent edits a file, PI Review automatically captures the original content, the new content, and a diff showing exactly what changed. Nothing extra to do — it just works.

2. Open the review UI

Run /review in PI to open the web interface. You'll see:

• A sidebar listing every file that was changed
• A main panel showing the diff for the selected file
• Status badges: Pending (yellow), Accepted (green), Reverted (grey)

3. Review changes

For each file you can choose between two views:

• Diff view — shows only the changed lines
• Full file view — shows the complete file with changes highlighted in green (additions) and red (deletions). A down-arrow button jumps you to the next change.

4. Accept or revert

• Accept — keeps the agent's changes. Future edits to the same file will diff against the accepted version.
• Revert — restores the file to its original content before the agent touched it.

You can do this per file or globally with the "Accept All" / "Revert All" buttons.

5. Leave comments

Click any line number to add a comment. Comments are sent to the agent as instructions — useful for asking "why did you change this?" or requesting a fix without leaving the review UI.

6. Check history

Every accept or revert is recorded. Files with history show a collapsible list of past cycles, so you can see the full timeline of what happened.

7. Talk to the agent

Use the Chat button to start an open conversation with the agent. The chat panel slides in from the right — you can resize it by dragging the left edge.

8. Reference code

Right-click on any line or selection to open the "Reference this code" menu. This sends the selected code along with a question to the agent.

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Key Features

Feature	Description
File tracking	Automatically captures changes from edit, write, and bash tools
Unified diffs	Merges multiple edits to the same file into a single, readable diff
Diff view	Shows only changed lines
Full file view	Shows the complete file with inline diff highlighting
Scroll to next diff	In full file view, jumps to the next changed line
Accept / Revert	Per-file or global accept/revert with history tracking
Line comments	Click a line number to leave a comment for the agent
Reference code	Right-click code to ask the agent about specific lines
Chat	Open-ended conversation with the agent from inside the review UI
Resizable panels	Drag the divider between sidebar and main content, or the chat panel edge
History timeline	Every accept/revert is recorded for future reference
Live updates	The UI refreshes automatically when new changes come in
Open in VS Code	Click the VS Code icon to jump straight to a file
External change detection	Warns when a file was modified outside the agent

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Project Structure

pi-review/
├── src/
│   ├── index.ts          — PI extension entry point
│   ├── tracker.ts        — Core engine: tracks, merges, accepts, reverts
│   ├── server.ts         — HTTP server with SSE and REST API
│   ├── types.ts          — TypeScript type definitions
│   └── frontend/
│       ├── app.tsx       — Root Preact component
│       ├── main.tsx      — Frontend entry point
│       ├── store.ts      — API client and SSE manager
│       ├── styles.css    — All styles
│       ├── utils.ts      — Helper functions
│       ├── highlight.ts  — Syntax highlighting
│       ├── selection.ts  — Line selection utilities
│       └── components/
│           ├── file-viewer.tsx      — File diff/full-file display
│           ├── full-file-view.tsx   — Full file with diff highlighting
│           ├── diff-table.tsx       — Unified diff table
│           ├── header.tsx           — Top toolbar
│           ├── sidebar.tsx          — File list sidebar
│           ├── chat-panel.tsx       — Agent chat (slide-in panel)
│           └── reference-panel.tsx  — Code reference panel
├── dist/                — Built frontend assets
├── build.mjs            — esbuild config for frontend
├── package.json         — PI extension config in the `pi` key
└── README.md

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Installation

PI Review is a PI extension. It's loaded from the pi key in package.json:

"pi": {
  "extensions": ["./src/index.ts"]
}

To use it in another project, either:

# Install from git
pi install git:github.com/danielmeneses/pi-review

# Or install locally from a local path
pi install /path/to/pi-review -l

Extensions and packages are placed in ~/.pi/agent/ (global) or .pi/ (project-local). See the PI extensions docs for more details.

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Getting Started

# Build the frontend (required after any UI changes)
npm run build:frontend

# In PI, start the review UI
/review

The server picks a port at runtime (defaults to 3123, falls back to a random port if busy). Run /review to open it in your browser.

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Commands

PI Command	Description
/review	Open the review UI in your browser
/accept-all	Accept all pending changes
/revert-all	Revert all pending changes (with confirmation)

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State Persistence

PI Review saves its state to .pi-review/state.json in your project root. This means:

• Changes survive PI restarts
• You can close and reopen the review UI without losing data
• Accepted/reverted history is preserved between sessions

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Requirements

• Node.js 18+
• PI coding agent
• A modern browser (Chrome, Firefox, Safari 14+)