Complete Call Flow Example

User Input

"Send an email to alice@example.com with subject 'Hello' using Mail"

Agent Behavior

1. Call resources/list -> Discover app:com.apple.mail
2. Call resources/read(app:com.apple.mail) -> Get send_email tool
3. Construct MCP tools/call request

Gateway Behavior (macOS Example)

1. Parse aai.json
2. Replace parameters in script template:

   tell application "Mail"
       set newMessage to make new outgoing message with properties {subject:"Hello", content:"Hi Alice...", visible:false}
       tell newMessage
           make new to recipient at beginning of to recipients with properties {address:"alice@example.com"}
           send
       end tell
   end tell
   return "{\"success\":true, \"message_id\":\"generated\"}"

3. Execute AppleScript:

   osascript -e 'tell application "Mail"...'

4. If it's the first call, macOS pops up TCC authorization dialog
5. After user authorizes, script executes successfully
6. Parse return value (JSON string)
7. Return result:

{
  "jsonrpc": "2.0",
  "id": 3,
  "result": {
    "content": [
      {
        "type": "text",
        "text": "Email sent successfully. Message ID: generated"
      }
    ]
  }
}

User Experience

• macOS pops up TCC authorization dialog on first use
• User clicks [OK]
• Subsequent calls execute silently

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