Duplicate messages being sent from DevPhone to TAC Application

[micaswyers-work]

Using the DevPhone to communicate with a TAC-based application causes duplicate messages to be sent to the application. This causes the TAC application to send two (different AI-composed) messages back to the DevPhone.

STR:

• Run TAC application & DevPhone
• Message the application from the DevPhone
• Get two different messages back from the DevPhone

Application logging

INFO: connection closed 2026-07-15 10:33:10 - tac.tac.channels.sms - INFO - CONVERSATION | Started SMS conversation [conversation_id=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0, profile_id=None] [sms] conv=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0 phone=XXXXXXXXX2253 → "Hi, I'd like to check on my bag." [sms] conv=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0 phone=XXXXXXXXX2253 → "Hi, I'd like to check on my bag." [tool] check_bag_status({'confirmation_code': 'OLL100And1'}) → {"error": "No reservation found for code OLL100And1"} [tool] check_bag_status({'confirmation_code': 'OLL100And1'}) → {"error": "No reservation found for code OLL100And1"} ← "I'm sorry, it seems like there might be a mistake with the reservation code OLL100And1. Could you please verify the code for me or let me know if you have any other details that might help?" 2026-07-15 10:33:15 - tac.tac.channels.sms - INFO - Sent SMS response via Actions API [conversation_id=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0, to_address=+4***2253] [tool] get_reservations_by_phone({'phone': 'XXXXXXXXX2253'}) → {"reservations": [{"confirmation_code": "OWL101", "passenger_name": "Mica Swyers", "flight_number": "OA530", "origin": " [tool] check_bag_status({'confirmation_code': 'OWL101'}) → {"confirmation_code": "OWL101", "passenger_name": "Mica Swyers", "bag_status": "Currently taking a hydration break"} ← "Your bag is currently taking a "hydration break." While it should be reunited with you soon, please let me know if I can assist with anything else during this time!" 2026-07-15 10:33:18 - tac.tac.channels.sms - INFO - Sent SMS response via Actions API [conversation_id=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0, to_address=+4***2253] [sms] conv=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0 phone=XXXXXXXXX2253 → "Can you give me a coupon code?" [sms] conv=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0 phone=XXXXXXXXX2253 → "Can you give me a coupon code?" [tool] send_coupon({'confirmation_code': 'OLL100And1', 'reason': 'delayed baggage'}) → {"error": "No reservation found for code OLL100And1"} [tool] send_coupon({'confirmation_code': 'OLL100And1', 'reason': 'delayed baggage'}) → {"error": "No reservation found for code OLL100And1"} ← "I'm sorry, it seems there was an error finding your reservation with the code "OLL100And1." Could you double-check the confirmation code, or provide any additional details you might have? I'll be happy to issue the coupon once we resolve this." ← "I apologize, but it seems there was an error with the reservation code. Could you please confirm the correct reservation code for me?" 2026-07-15 10:33:38 - tac.tac.channels.sms - INFO - Sent SMS response via Actions API [conversation_id=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0, to_address=+4***2253] 2026-07-15 10:33:38 - tac.tac.channels.sms - INFO - Sent SMS response via Actions API [conversation_id=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0, to_address=+4***2253] [sms] conv=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0 phone=XXXXXXXXX2253 → "OWL101" [sms] conv=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0 phone=XXXXXXXXX2253 → "OWL101" [tool] send_coupon({'confirmation_code': 'OWL101', 'reason': 'delayed baggage'}) → {"confirmation_code": "OWL101", "passenger_name": "Mica Swyers", "coupon_code": "OWL-69D1F7", "value": "$50 Owl Airlines [tool] send_coupon({'confirmation_code': 'OWL101', 'reason': 'bag status check'}) → {"confirmation_code": "OWL101", "passenger_name": "Mica Swyers", "coupon_code": "OWL-D7B213", "value": "$50 Owl Airlines ← "Thanks for your patience. I've issued a $50 travel credit as a goodwill gesture for your delayed baggage. Your coupon code is OWL-69D1F7. Let me know if there's anything else I can assist you with!" ← "I've issued a $50 travel credit coupon for you. Your coupon code is OWL-D7B213. If there's anything else you need, just let me know!" 2026-07-15 10:33:57 - tac.tac.channels.sms - INFO - Sent SMS response via Actions API [conversation_id=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0, to_address=+4***2253] 2026-07-15 10:33:57 - tac.tac.channels.sms - INFO - Sent SMS response via Actions API [conversation_id=conv_conversation_01kxjhyye7ewwtvg1e0yw6fzk0, to_address=+4***2253]

Screenshot:

[kuroxx]

Side note:
We don’t think this is caused by the Orchestrator config or agent code. It looks like an issue with the Twilio Dev Phone.

When an SMS is sent from the Dev Phone to the agent’s number, Conversation Orchestrator receives it twice as two separate communication_created events. Each event has a different communication ID and i-twilio-idempotency-token, so the agent replies twice.

We confirmed this by sending the same SMS from a personal phone number, which resulted in one inbound message and one reply. Messages from the Dev Phone were consistently duplicated.

Also, TAC only dedupes events with the same i-twilio-idempotency-token. Since these are separate communications with different tokens, TAC does not dedupe them.