Plannotator

A plan review UI for Claude Code that intercepts ExitPlanMode via hooks, letting users approve or request changes with annotated feedback. Also provides code review for git diffs and annotation of arbitrary markdown files.

Project Structure

plannotator/
├── apps/
│   ├── hook/                     # Claude Code plugin
│   │   ├── .claude-plugin/plugin.json
│   │   ├── commands/             # Slash commands (plannotator-review.md, plannotator-annotate.md)
│   │   ├── hooks/hooks.json      # PermissionRequest hook config
│   │   ├── server/index.ts       # Entry point (plan + review + annotate + archive subcommands)
│   │   └── dist/                 # Built single-file apps (index.html, review.html)
│   ├── opencode-plugin/          # OpenCode plugin
│   │   ├── commands/             # Slash commands (plannotator-review.md, plannotator-annotate.md)
│   │   ├── index.ts              # Plugin entry with submit_plan tool + review/annotate event handlers
│   │   ├── plannotator.html      # Built plan review app
│   │   └── review-editor.html    # Built code review app
│   ├── marketing/                # Marketing site, docs, and blog (plannotator.ai)
│   │   └── astro.config.mjs      # Astro 5 static site with content collections
│   ├── paste-service/            # Paste service for short URL sharing
│   │   ├── core/                 # Platform-agnostic logic (handler, storage interface, cors)
│   │   ├── stores/               # Storage backends (fs, kv, s3)
│   │   └── targets/              # Deployment entries (bun.ts, cloudflare.ts)
│   ├── review/                   # Standalone review server (for development)
│   │   ├── index.html
│   │   ├── index.tsx
│   │   └── vite.config.ts
│   └── vscode-extension/         # VS Code extension — opens plans in editor tabs
│       ├── bin/                   # Router scripts (open-in-vscode, xdg-open)
│       ├── src/                   # extension.ts, cookie-proxy.ts, ipc-server.ts, panel-manager.ts, editor-annotations.ts, vscode-theme.ts
│       └── package.json           # Extension manifest (publisher: backnotprop)
├── packages/
│   ├── server/                   # Shared server implementation
│   │   ├── index.ts              # startPlannotatorServer(), handleServerReady()
│   │   ├── review.ts             # startReviewServer(), handleReviewServerReady()
│   │   ├── annotate.ts           # startAnnotateServer(), handleAnnotateServerReady()
│   │   ├── storage.ts            # Re-exports from @plannotator/shared/storage
│   │   ├── share-url.ts          # Server-side share URL generation for remote sessions
│   │   ├── remote.ts             # isRemoteSession(), getServerPort()
│   │   ├── browser.ts            # openBrowser()
│   │   ├── draft.ts              # Re-exports from @plannotator/shared/draft
│   │   ├── integrations.ts       # Obsidian, Bear integrations
│   │   ├── ide.ts                # VS Code diff integration (openEditorDiff)
│   │   ├── editor-annotations.ts  # VS Code editor annotation endpoints
│   │   └── project.ts            # Project name detection for tags
│   ├── ui/                       # Shared React components + theme
│   │   ├── theme.css             # Single source of truth for color tokens + Tailwind bridge
│   │   ├── components/           # Viewer, Toolbar, Settings, etc.
│   │   │   ├── icons/            # Shared SVG icon components (themeIcons, etc.)
│   │   │   ├── plan-diff/        # PlanDiffBadge, PlanDiffViewer, clean/raw diff views
│   │   │   └── sidebar/          # SidebarContainer, SidebarTabs, VersionBrowser, ArchiveBrowser
│   │   ├── utils/                # parser.ts, sharing.ts, storage.ts, planSave.ts, agentSwitch.ts, planDiffEngine.ts, planAgentInstructions.ts
│   │   ├── hooks/                # useAnnotationHighlighter.ts, useSharing.ts, usePlanDiff.ts, useSidebar.ts, useLinkedDoc.ts, useAnnotationDraft.ts, useCodeAnnotationDraft.ts, useArchive.ts
│   │   └── types.ts
│   ├── ai/                       # Provider-agnostic AI backbone (providers, sessions, endpoints)
│   ├── shared/                   # Shared types, utilities, and cross-runtime logic
│   │   ├── storage.ts            # Plan saving, version history, archive listing (node:fs only)
│   │   ├── draft.ts              # Annotation draft persistence (node:fs only)
│   │   └── project.ts            # Pure string helpers (sanitizeTag, extractRepoName, extractDirName)
│   ├── editor/                   # Plan review App.tsx
│   └── review-editor/            # Code review UI
│       ├── App.tsx               # Main review app
│       ├── components/           # DiffViewer, FileTree, ReviewSidebar
│       ├── dock/                 # Dockview center panel infrastructure
│       ├── demoData.ts           # Demo diff for standalone mode
│       └── index.css             # Review-specific styles
├── .claude-plugin/marketplace.json  # For marketplace install
└── legacy/                       # Old pre-monorepo code (reference only)

Server Runtimes

There are two separate server implementations with the same API surface:

• Bun server (packages/server/) — used by both Claude Code (apps/hook/) and OpenCode (apps/opencode-plugin/). These plugins import directly from @plannotator/server.
• Pi server (apps/pi-extension/server/) — a standalone Node.js server for the Pi extension. It mirrors the Bun server's API but uses node:http primitives instead of Bun's Request/Response APIs.

When adding or modifying server endpoints, both implementations must be updated. Runtime-agnostic logic (store, validation, types) lives in packages/shared/ and is imported by both.

Installation

Via plugin marketplace (when repo is public):

/plugin marketplace add backnotprop/plannotator

Local testing:

claude --plugin-dir ./apps/hook

Environment Variables

Legacy: SSH_TTY and SSH_CONNECTION are still detected when PLANNOTATOR_REMOTE is unset. Set PLANNOTATOR_REMOTE=1 / true to force remote mode or 0 / false to force local mode.

Devcontainer/SSH usage:

export PLANNOTATOR_REMOTE=1
export PLANNOTATOR_PORT=9999

Plan Review Flow

Claude calls ExitPlanMode
        ↓
PermissionRequest hook fires
        ↓
Bun server reads plan from stdin JSON (tool_input.plan)
        ↓
Server starts on random port, opens browser
        ↓
User reviews plan, optionally adds annotations
        ↓
Approve → stdout: {"hookSpecificOutput":{"decision":{"behavior":"allow"}}}
Deny    → stdout: {"hookSpecificOutput":{"decision":{"behavior":"deny","message":"..."}}}

Code Review Flow

User runs /plannotator-review command
        ↓
Claude Code: plannotator review subcommand runs
OpenCode: event handler intercepts command
        ↓
git diff captures unstaged changes
        ↓
Review server starts, opens browser with diff viewer
        ↓
User annotates code, provides feedback
        ↓
Send Feedback → feedback sent to agent session
Approve → "LGTM" sent to agent session

Annotate Flow

User runs /plannotator-annotate <file.md> command
        ↓
Claude Code: plannotator annotate subcommand runs
OpenCode: event handler intercepts command
        ↓
Markdown file read from disk
        ↓
Annotate server starts (reuses plan editor HTML with mode:"annotate")
        ↓
User annotates markdown, provides feedback
        ↓
Send Annotations → feedback sent to agent session

Archive Flow

User runs plannotator archive (CLI) or /plannotator-archive (Pi)
        ↓
Server starts in mode:"archive", reads ~/.plannotator/plans/
        ↓
Browser opens read-only archive viewer (sharing disabled)
        ↓
User browses saved plan decisions with approved/denied badges
        ↓
Done → POST /api/done closes the browser

During normal plan review, an Archive sidebar tab provides the same browsing via linked doc overlay without leaving the current session.

Server API

Plan Server (packages/server/index.ts)

Review Server (packages/server/review.ts)

Annotate Server (packages/server/annotate.ts)

All servers use random ports locally or fixed port (19432) in remote mode.

Paste Service (apps/paste-service/)

Runs as a separate service on port 19433 (self-hosted) or as a Cloudflare Worker (hosted).

Plan Version History

Every plan is automatically saved to ~/.plannotator/history/{project}/{slug}/ on arrival, before the user sees the UI. Versions are numbered sequentially (001.md, 002.md, etc.). The slug is derived from the plan's first # Heading + today's date via generateSlug(), scoped by project name (git repo or cwd). Same heading on the same day = same slug = same plan being iterated on. Identical resubmissions are deduplicated (no new file if content matches the latest version).

This powers the version history API (/api/plan/version, /api/plan/versions) and the plan diff system.

History saves independently of the planSave user setting (which controls decision snapshots in ~/.plannotator/plans/). Storage functions live in packages/shared/storage.ts (runtime-agnostic, re-exported by packages/server/storage.ts). Pi copies the shared files at build time. Slug format: {sanitized-heading}-YYYY-MM-DD (heading first for readability).

Plan Diff

When a user denies a plan and Claude resubmits, the UI shows what changed between versions. A +N/-M badge appears below the document card; clicking it toggles between normal view and diff view.

Diff engine (packages/ui/utils/planDiffEngine.ts): Uses the diff npm package (diffLines()) to compute line-level diffs. Groups consecutive remove+add into "modified" blocks. Returns PlanDiffBlock[] and PlanDiffStats.

Two view modes (toggle via PlanDiffModeSwitcher):

• Rendered (PlanCleanDiffView): Color-coded left borders — green (added), red (removed/strikethrough), yellow (modified)
• Raw (PlanRawDiffView): Monospace +/- lines, git-style

State (packages/ui/hooks/usePlanDiff.ts): Manages base version selection, diff computation, and version fetching. The server sends previousPlan with the initial /api/plan response; the hook auto-diffs against it. Users can select any prior version from the sidebar Version Browser.

Diff annotations: The clean diff view supports block-level annotation — hover over added/removed/modified sections to annotate entire blocks. Annotations carry a diffContext field (added/removed/modified). Exported feedback includes [In diff content] labels.

Annotation hook (packages/ui/hooks/useAnnotationHighlighter.ts): Annotation infrastructure used by Viewer.tsx. Manages web-highlighter lifecycle, toolbar/popover state, annotation creation, text-based restoration, and scroll-to-selected. The diff view uses its own block-level hover system instead.

Sidebar (packages/ui/hooks/useSidebar.ts): Shared left sidebar with three tabs — Table of Contents, Version Browser, and Archive. The "Auto-open Sidebar" setting controls whether it opens on load (TOC tab only). In archive mode, the sidebar opens to the Archive tab automatically.

Data Types

Location: packages/ui/types.ts

enum AnnotationType {
  DELETION = "DELETION",
  COMMENT = "COMMENT",
  GLOBAL_COMMENT = "GLOBAL_COMMENT",
}

interface ImageAttachment {
  path: string;   // temp file path
  name: string;   // human-readable label (e.g., "login-mockup")
}

interface Annotation {
  id: string;
  blockId: string;
  startOffset: number;
  endOffset: number;
  type: AnnotationType;
  text?: string; // For comment
  originalText: string; // The selected text
  createdA: number; // Timestamp
  author?: string; // Tater identity
  images?: ImageAttachment[]; // Attached images with names
  source?: string; // External tool identifier (e.g., "eslint") — set when annotation comes from external API
  diffContext?: 'added' | 'removed' | 'modified'; // Set when annotation created in plan diff view
  startMeta?: { parentTagName; parentIndex; textOffset };
  endMeta?: { parentTagName; parentIndex; textOffset };
}

interface Block {
  id: string;
  type: "paragraph" | "heading" | "blockquote" | "list-item" | "code" | "hr";
  content: string;
  level?: number; // For headings (1-6)
  language?: string; // For code blocks
  order: number;
  startLine: number;
}

Markdown Parser

Location: packages/ui/utils/parser.ts

parseMarkdownToBlocks(markdown) splits markdown into Block objects. Handles:

• Headings (#, ##, etc.)
• Code blocks (``` with language extraction)
• List items (-, *, 1.)
• Blockquotes (>)
• Horizontal rules (---)
• Paragraphs (default)

exportAnnotations(blocks, annotations, globalAttachments) generates human-readable feedback for Claude. Images are referenced by name: [image-name] /tmp/path.... Annotations with diffContext include [In diff content] labels.

Annotation System

Selection mode: User selects text → toolbar appears → choose annotation type Redline mode: User selects text → auto-creates DELETION annotation

Text highlighting uses web-highlighter library. Code blocks use manual <mark> wrapping (web-highlighter can't select inside <pre>).

URL Sharing

Location: packages/ui/utils/sharing.ts, packages/ui/hooks/useSharing.ts

Shares full plan + annotations via URL hash using deflate compression. For large plans, short URLs are created via the paste service (user must explicitly confirm).

Payload format:

// Image in shareable format: plain string (old) or [path, name] tuple (new)
type ShareableImage = string | [string, string];

interface SharePayload {
  p: string; // Plan markdown
  a: ShareableAnnotation[]; // Compact annotations
  g?: ShareableImage[]; // Global attachments
  d?: (string | null)[]; // diffContext per annotation, parallel to `a`
}

type ShareableAnnotation =
  | ["D", string, string | null, ShareableImage[]?] // [type, original, author, images?]
  | ["C", string, string, string | null, ShareableImage[]?] // [type, original, comment, author, images?]
  | ["G", string, string | null, ShareableImage[]?]; // [type, comment, author, images?]

Compression pipeline:

1. JSON.stringify(payload)
2. CompressionStream('deflate-raw')
3. Base64 encode
4. URL-safe: replace +/= with -_

On load from shared URL:

1. Parse hash, decompress, restore annotations
2. Find text positions in rendered DOM via text search
3. Apply <mark> highlights
4. Clear hash from URL (prevents re-parse on refresh)

Settings Persistence

Location: packages/ui/utils/storage.ts, planSave.ts, agentSwitch.ts

Uses cookies (not localStorage) because each hook invocation runs on a random port. Settings include identity, plan saving (enabled/custom path), and agent switching (OpenCode only).

Syntax Highlighting

Code blocks use bundled highlight.js. Language is extracted from fence (```rust) and applied as language-{lang}class. Each block highlighted individually viahljs.highlightElement().

Requirements

• Bun runtime
• Claude Code with plugin/hooks support, or OpenCode
• Cross-platform: macOS (open), Linux (xdg-open), Windows (start)

Development

bun install

# Run any app
bun run dev:hook       # Hook server (plan review)
bun run dev:review     # Review editor (code review)
bun run dev:portal     # Portal editor
bun run dev:marketing  # Marketing site
bun run dev:vscode     # VS Code extension (watch mode)

Build

bun run build:hook       # Single-file HTML for hook server
bun run build:review     # Code review editor
bun run build:opencode   # OpenCode plugin (copies HTML from hook + review)
bun run build:portal     # Static build for share.plannotator.ai
bun run build:marketing  # Static build for plannotator.ai
bun run build:vscode     # VS Code extension bundle
bun run package:vscode   # Package .vsix for marketplace
bun run build            # Build hook + opencode (main targets)

Important: Build order matters. The hook build (build:hook) copies pre-built HTML from apps/review/dist/. If you change UI code in packages/ui/, packages/editor/, or packages/review-editor/, you must rebuild the review app first, then the hook:

bun run --cwd apps/review build && bun run build:hook   # For review UI changes
bun run build:hook                                       # For plan UI changes only
bun run build:hook && bun run build:opencode             # For OpenCode plugin

Running only build:hook after review-editor changes will copy stale HTML files. When testing locally with a compiled binary, the full sequence is:

bun run --cwd apps/review build && bun run build:hook && \
  bun build apps/hook/server/index.ts --compile --outfile ~/.local/bin/plannotator

Running only build:opencode will copy stale HTML files.

Marketing Site

apps/marketing/ is the plannotator.ai website — landing page, documentation, and blog. Built with Astro 5 (static output, zero client JS except a theme toggle island). Docs are markdown files in src/content/docs/, blog posts in src/content/blog/, both using Astro content collections. Tailwind CSS v4 via @tailwindcss/vite. Deploys to S3/CloudFront via GitHub Actions on push to main.

Test plugin locally

claude --plugin-dir ./apps/hook