Skills and MCP

This page covers how to install global skills (slash commands) and MCP servers for both Claude Code CLI and Codex CLI, and documents the apple-tools MCP used by Apple Flow.

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Skills (Slash Commands)

Skills are SKILL.md files that define custom slash commands. The directory name becomes the command name (e.g. ~/.claude/skills/deploy/SKILL.md → /deploy).

Claude Code CLI

# Create a global skill
mkdir -p ~/.claude/skills/my-command
cat > ~/.claude/skills/my-command/SKILL.md << 'EOF'
# My Command

Description of what this slash command does.

## Steps
1. Do thing one
2. Do thing two
EOF

Codex CLI

Same SKILL.md format as Claude Code. To disable a skill without deleting it, add to ~/.codex/config.toml:

[[skills.config]]
path = "/path/to/skill/SKILL.md"
enabled = false

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MCP Servers

MCP (Model Context Protocol) servers give the AI access to external tools and data sources.

Claude Code CLI

# Add a global MCP server via CLI
claude mcp add --scope user --transport stdio my-server -- npx -y my-mcp-package

# Add an HTTP-based MCP server
claude mcp add --scope user --transport http my-server https://my-server.example.com

# Add a project-scoped MCP (written to .mcp.json)
claude mcp add --scope project --transport stdio my-server -- npx -y my-mcp-package

# List configured MCP servers
claude mcp list

Or edit ~/.claude/settings.json directly:

{
  "mcpServers": {
    "apple-tools": {
      "command": "npx",
      "args": ["-y", "apple-tools-mcp"]
    }
  }
}

Codex CLI

# Add via CLI
codex mcp add apple-tools

Or edit ~/.codex/config.toml directly:

[mcp_servers.apple-tools]
command = "npx"
args = ["-y", "apple-tools-mcp"]

# HTTP-based server example
[mcp_servers.my-http-server]
url = "https://my-server.example.com"
bearer_token_env_var = "MY_TOKEN"

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Side-by-Side Summary

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apple-tools MCP (Global Setup)

apple-tools-mcp provides semantic search across Apple Mail, Messages, and Calendar — giving the AI real-time access to your local Apple data.

Important: Install it globally (not just project-scoped) so it's available whenever you invoke Claude or Codex from any directory.

Install & configure for Claude Code CLI

# Install globally
npm install -g apple-tools-mcp

# Add to Claude Code global config
claude mcp add --scope user --transport stdio apple-tools -- npx -y apple-tools-mcp

Or add manually to ~/.claude/settings.json:

{
  "mcpServers": {
    "apple-tools": {
      "command": "npx",
      "args": ["-y", "apple-tools-mcp"]
    }
  }
}

Install & configure for Codex CLI

Add to ~/.codex/config.toml:

[mcp_servers.apple-tools]
command = "npx"
args = ["-y", "apple-tools-mcp"]

What apple-tools provides

Note: First run may take a few minutes to build the local vector index. The index is stored locally and is never sent to any external service.

Notion MCP (Global Setup)

The recommended package is @notionhq/notion-mcp-server, which exposes Notion workspace actions and search to AI tools.

Add to ~/.codex/config.toml:

[mcp_servers.notion]
command = "npx"
args = ["-y", "@notionhq/notion-mcp-server"]

Set your Notion token in the environment before running Codex:

export NOTION_API_KEY="<your_notion_integration_token>"

Security reminder: avoid hardcoding API keys in repo-tracked files; prefer environment-based injection from your shell or secret manager.