Caller: "I need to speak to a manager."
Agent: "Of course, I'll transfer you now. One moment please."
→ Call transfers to +14155551234

Caller: "I have a billing dispute."
Agent: "Let me connect you with our billing team. One moment."
→ Agent calls billing team, provides summary
→ Caller is connected to the billing agent

curl -X PATCH https://api.thinnest.ai/agents/agent_abc123 \
  -H "Authorization: Bearer $THINNESTAI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "voice_tools": {
      "transfer_call": {
        "enabled": true,
        "type": "cold",
        "default_destination": "+14155551234",
        "department_routing": {
          "billing": "+14155552222",
          "sales": "+14155553333",
          "support": "+14155554444"
        },
        "hold_message": "Please hold while I transfer you.",
        "fallback_action": "voicemail"
      }
    }
  }'

If the caller asks to speak to a human, sales, billing, or support team,
transfer the call to the appropriate department:
- Sales inquiries → transfer to sales
- Billing questions → transfer to billing
- Technical issues you cannot resolve → transfer to support
- "Speak to a manager" → transfer to the default number

Before transferring, briefly summarize the caller's issue so the human
agent has context.

{
  "department_routing": {
    "sales": "+14155551111",
    "billing": "+14155552222",
    "technical_support": "+14155553333",
    "manager": "+14155554444",
    "scheduling": "+14155555555"
  }
}