Confirm caller ID before sending SMS

functions/start_function.py           ← stash caller_number at call start
functions/caller_number_confirmed.py  ← check presence, compare last four
config/sms_templates.yaml             ← the SMS template (alongside other templates)
topics/Send Booking Link.yaml         ← topic that triggers the flow

from _gen import *  # <AUTO GENERATED>


def start_function(conv: Conversation):
    conv.state.caller_number = conv.caller_number
    return str()

from _gen import *  # <AUTO GENERATED>


@func_description(
    "Called after the caller confirms or provides a number for us to send the SMS to. "
    "confirmed: True if they confirmed the number on file, False if they want to use a different one. "
    "provided_number: the number they provided if confirmed is False."
)
@func_parameter("confirmed", "Whether the caller confirmed the number on file")
@func_parameter("provided_number", "The number the caller provided if confirmed is False; pass an empty string if confirmed is True")
def caller_number_confirmed(conv: Conversation, confirmed: bool, provided_number: str):
    if confirmed and conv.state.caller_number:
        to_number = conv.state.caller_number
    elif provided_number:
        to_number = provided_number
    else:
        return "Ask the caller to provide the number where we should send the link."

    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."

enabled: true
example_queries:
  - Can you send me the booking link?
  - Can you text me a link?
  - Send me the details by text
  - I'd like a link to book online
content: |-
  The booking link is available by SMS.
actions: |-
  ## If the caller's number is available
  Tell the caller you can send the link to the number ending in the last four digits of $caller_number.
  Ask them to confirm or provide a different number.
  Use {{fn:caller_number_confirmed}} once they respond.

  ## If the caller's number is not available
  Ask the caller for the number where we should send the link.
  Use {{fn:caller_number_confirmed}} with confirmed=False and the number they provide.

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