Checkpoint

A macOS menu bar app that gives you a visual approval UI for Claude Code tool calls.

When Claude Code wants to run a command, edit a file, or fetch a URL, this app intercepts the request and shows a prompt in your menu bar. You can allow, deny, or grant session-wide permission.

How it works

1. On launch, the app starts an HTTP server on a local port and registers a PreToolUse hook in ~/.claude/settings.json
2. When Claude Code invokes a matched tool, it sends the request to the app
3. A notification appears and the menu bar icon shows a countdown
4. You approve or deny from the menu bar popover (or from the notification actions)
5. On quit, the hook is cleanly removed from settings

Intercepted tools

The hook matches tools that modify state or reach external services:

• File mutation — Edit, Write, MultiEdit, NotebookEdit
• Shell — Bash
• Network — WebFetch, WebSearch
• Extensibility — Skill, mcp__* (all MCP server tools)

Read-only tools (Read, Glob, Grep, LSP, etc.) pass through without prompting.

Menu bar states

Icon	Meaning
checkmark.shield	Server running, no pending requests
exclamationmark.shield + ring	Request pending, countdown active
shield.slash	Server not running

Session rules

Clicking Always Allow on a request creates a session rule like Bash(npm *) or Edit(**/*.tsx). All future matching requests from that session are auto-approved. Active rules are listed in the menu bar popover and can be revoked individually.

Requirements

• macOS 14+
• Xcode 15+
• mise (installs XcodeGen and SwiftLint automatically)

Project structure

Sources/
  App/                  # App entry point and AppDelegate
  Models/               # PermissionRequest, PermissionResponse, JSONValue
  Server/               # TCP server handling HTTP hook requests
  Services/             # HookConfigManager (settings.json), NotificationManager
  ViewModels/           # PermissionManager (state, session rules, request lifecycle)
  Views/                # MenuBarIconView, PermissionListView, PermissionDetailView
Tests/
  ...                   # Unit tests for models, services, and view models

Building

The Xcode project is generated from project.yml via XcodeGen. If you have mise installed, it handles tool versions automatically:

mise install          # install XcodeGen + SwiftLint
mise run generate     # generate Checkpoint.xcodeproj
mise run build        # build the app

Or manually:

xcodegen generate
xcodebuild -project Checkpoint.xcodeproj -scheme Checkpoint -configuration Release build

Note: The app runs without App Sandbox because it needs to read/write ~/.claude/settings.json and bind a local TCP port for the hook server.

License

MIT