SMS link with transfer fallback

functions/start_function.py           ← stash caller_number
functions/send_link_or_transfer.py    ← SMS or handoff decision
config/sms_templates.yaml             ← SMS template (alongside other templates)
config/handoffs.yaml                  ← transfer destination (alongside other handoffs)
topics/Get Booking Link.yaml          ← triggers the pattern

from _gen import *  # <AUTO GENERATED>


@func_description(
    "Called when the caller has been offered the booking link by SMS or by speaking to an agent. "
    "wants_sms: True if they want the link by text, False if they want to speak to someone."
)
@func_parameter("wants_sms", "True if the caller wants the SMS link, False if they want to speak to an agent")
def send_link_or_transfer(conv: Conversation, wants_sms: bool):
    if wants_sms:
        to_number = conv.state.caller_number
        if not to_number:
            return (
                "Tell the caller we were unable to send the SMS because we do not have their number. "
                "Offer to transfer them to an agent instead or ask for a number to send to."
            )
        conv.send_sms_template(to_number=to_number, template="booking_link")
        return "Tell the caller the link has been sent and ask if there is anything else you can help with."
    else:
        conv.call_handoff(
            destination="agent_queue",
            reason="caller_requested_agent",
            utterance="Let me connect you with a member of the team now.",
        )

enabled: true
example_queries:
  - Can you send me a link to book?
  - How do I book online?
  - I want to make a reservation online
  - Send me a booking link
  - Can I speak to someone about booking?
content: |-
  Bookings can be made online at book.example.com, or by speaking with a team member.
actions: |-
  Ask the caller if they would like the link sent by text message, or if they would prefer to speak to someone.
  Use {{fn:send_link_or_transfer}} once they respond.

handoffs:
  - name: agent_queue
    description: Transfer to live agent queue
    is_default: true
    sip_config:
      method: refer
      phone_number: "+441234567890"

sms_templates:
  - name: booking_link
    text: "Here's your booking link: https://book.example.com"
    env_phone_numbers:
      sandbox: "+441111111111"
      pre_release: "+442222222222"
      live: "+443333333333"

ENV_SENDER_NUMBERS = {
    "sandbox": "+441111111111",
    "pre-release": "+442222222222",
    "live": "+443333333333",
}

def send_link_or_transfer(conv: Conversation, wants_sms: bool):
    if wants_sms:
        from_number = ENV_SENDER_NUMBERS.get(conv.env, ENV_SENDER_NUMBERS["sandbox"])
        conv.send_sms(
            to_number=conv.state.caller_number,
            from_number=from_number,
            content="Here's your booking link: https://book.example.com",
        )
        return "Tell the caller the link has been sent."
    ...