⚛️ Nucleus: macOS Life Context Server

Give your AI Agent a Hippocampus.

nucleus-apple-mcp is a Model Context Protocol (MCP) server designed to unify your digital life on macOS. It allows AI agents (like Claude Desktop, Cursor, or custom agents) to securely read and interact with your personal data ecosystem.

Unlike fragile PyObjC bridges, Nucleus uses a hybrid architecture: a Python MCP server that orchestrates lightweight, JIT-compiled native Swift workers. This ensures type-safe, performant, and reliable access to Apple's native APIs while remaining easily distributable via uvx.

For a higher-level product overview, see docs/introducing-nucleus.md.

🔌 Integrations

✅ Available (current release)

• 📅 Calendar: Fetch upcoming schedules, check availability, and create events via EventKit.
• ✅ Reminders: Read pending tasks and manage your to-do lists via EventKit.
• 📝 Notes: List/search notes, read content, and add/export attachments via Notes.app (Apple Events).
• ❤️ Health: Read exported Apple Health metrics and raw samples from an S3-compatible object store.

🏗 Architecture

• Python: Handles the MCP protocol, request routing, and distribution (pip/uv).
• Swift: Embedded source code acts as a "Sidecar." It is compiled locally on the first run (using SwiftPM swift build) to interface directly with macOS private frameworks, bypassing the limitations of Python-Objective-C bridges.

📦 Swift Sidecar Layout

• Swift Package Root: src/nucleus_apple_mcp/sidecar/swift/ (includes Package.swift; CLI uses swift-argument-parser)
• Build Cache (macOS): ~/Library/Caches/nucleus-apple-mcp/sidecar/<build_id>/nucleus-apple-sidecar
• Optional Env Vars: NUCLEUS_APPLE_MCP_CACHE_DIR (overrides cache directory), NUCLEUS_SWIFT (swift path), NUCLEUS_SWIFTC (swiftc path)

🚀 Usage

# Run the CLI directly.
uvx --from nucleus-apple-mcp nucleus-apple health list-sample-catalog

# Or run the MCP server.
uvx nucleus-apple-mcp

🧰 CLI

Install the package once and use the unified nucleus-apple command:

uv tool install nucleus-apple-mcp

Examples:

# Calendar
nucleus-apple calendar list-events --start 2026-03-15T09:00:00+08:00 --end 2026-03-15T18:00:00+08:00 --pretty

# Reminders
nucleus-apple reminders list-reminders --due-end 2026-03-20 --pretty

# Notes
nucleus-apple notes list-notes --query project --include-plaintext-excerpt --pretty

# Health
nucleus-apple health read-daily-metrics --date 2026-03-14 --pretty

The CLI mirrors the MCP tool surface and emits JSON, which makes it suitable for shell automation and OpenClaw-style skills.

🔧 Add as an MCP server

This server uses the stdio transport (a local subprocess). The first run will compile the Swift sidecar.

Codex CLI

# Add the server (writes to ~/.codex/config.toml)
codex mcp add nucleus-apple -- uvx nucleus-apple-mcp

# Verify
codex mcp list

Claude Code

# Add the server (use --scope user to make it available globally)
claude mcp add --scope user nucleus-apple -- uvx nucleus-apple-mcp

# Verify
claude mcp list

You can also launch the server through the CLI:

nucleus-apple mcp serve

🪝 OpenClaw Skills

This repository includes OpenClaw-ready skills under skills/ for:

• nucleus-apple-calendar
• nucleus-apple-reminders
• nucleus-apple-notes
• nucleus-apple-health

Each skill depends on the nucleus-apple binary and is designed to be contributed upstream without changing the command surface.