How a message becomes an answer.
The path every WhatsApp message takes, and the stack behind the phone line. Instagram and web chat follow the same shape.
Six steps, every message.
The message arrives
Meta delivers the WhatsApp message to our webhook, and the signature is checked.
The hotel is identified
By the number the guest wrote to. Each hotel's settings are loaded from its own configuration.
It is handled exactly once
Every message id is claimed once, so a retry from Meta can never produce a second answer.
Your staff come first
If someone at the desk has taken over this conversation, the agent stays quiet.
The agent answers
In the guest's language, from the hotel's own information, checking rooms in the PMS when asked.
Reply and record
The reply goes out; the conversation and its cost are logged for the staff panel.
The stack, stated plainly.
Technical facts we are happy to be checked on.
- Messaging modelA LangChain / LangGraph agent on gpt-5.4-mini or DeepSeek deepseek-v4-flash, chosen per hotel.
- SessionsKept in Postgres, so a conversation survives restarts. Every message is handled once.
- Speech to textDeepgram nova-3, falling back to nova-2.
- VoiceElevenLabs or Freya text-to-speech.
- TelephonyLiveKit Cloud (EU) with a SIP trunk; transfers to your desk by SIP REFER.
- GuardrailsLimits on call length, silence and turns. No booking without a read-back and an explicit yes.
- HostingMessaging and this website run on our own server in Istanbul with daily database backups. Voice runs on LiveKit Cloud in the EU.