Set up a phone agent on your own Twilio number

{
  "name": "payment-agent",
  "greeting": "Hello, this is Riley from Acme on a recorded line about your account.",
  "voice": { "voice_id": "eve" },
  "system_prompt": "You are an Acme agent on a recorded call about an eighty three dollar and ten cent balance. One short sentence per reply.\nAfter the greeting say: \"Our records show a balance of eighty three dollars and ten cents, would you like to settle it by card now?\"\nWhen the caller agrees, call process_payment ONCE with amount \"83.10\". The card number, expiry and authorization are entered on the phone keypad - never ask for them by voice.\nIf the result is approved, say \"Your payment is approved.\" then ask \"What email address would you like your receipt sent to?\". When they give an email, call send_receipt with that email and amount \"83.10\". Then say \"Thank you, your receipt is on its way, goodbye.\"\nIf it is not approved, apologise and say the payment was not completed. Call each tool at most once.",
  "tools": [
    {
      "name": "process_payment",
      "description": "Charge the caller's card. Card number, expiry and authorization come from the telephone keypad.",
      "http": { "url": "https://webhook.site/your-unique-id", "http_method": "POST" },
      "parameters": {
        "type": "object",
        "properties": {
          "card_number": { "type": "string", "description": "Card number from the keypad." },
          "expiry":      { "type": "string", "description": "Expiry MMYY from the keypad." },
          "amount":      { "type": "string", "description": "Amount to charge, e.g. 83.10." },
          "authorization": { "type": "string", "description": "1 authorizes the charge." }
        },
        "required": ["card_number", "expiry", "amount"]
      },
      "dtmf_collected_arguments": [
        { "parameter_name": "card_number", "min_digits": 13, "max_digits": 19,
          "sensitive": true, "terminator": "#", "confirm": true,
          "prompt": "Using your keypad, please enter your card number, then press hash." },
        { "parameter_name": "expiry", "min_digits": 4, "max_digits": 4,
          "sensitive": true, "terminator": "#", "confirm": false,
          "prompt": "Now enter the expiry as four digits, month then year." },
        { "parameter_name": "authorization", "min_digits": 1, "max_digits": 1,
          "sensitive": false, "terminator": "#", "confirm": false,
          "prompt": "Do you authorize Acme to process a one-time payment of eighty three dollars and ten cents today? Press 1 to authorize, or 2 to cancel." }
      ]
    },
    {
      "name": "send_receipt",
      "description": "Email a payment receipt after the payment is approved.",
      "http": { "url": "https://webhook.site/your-unique-id", "http_method": "POST" },
      "parameters": {
        "type": "object",
        "properties": {
          "email":  { "type": "string", "description": "Caller's email address." },
          "amount": { "type": "string", "description": "Amount charged." }
        },
        "required": ["email", "amount"]
      }
    }
  ]
}