Problem
The company ran their entire B2B partner booking flow through WhatsApp groups. A partner posted a request; a human had to notice it, manually check vehicle and driver availability, calculate a fare, and reply. Typical turnaround was around 30 minutes with staff on hand — and well over two hours for requests arriving outside working hours. WhatsApp's official Business API offers no support for reading or acting on group messages, so there was no vendor-sanctioned automation path at all.
Analysis
Two distinct problems stacked. First: get a working connection into group chats, which the official API structurally does not permit. Second, once that's solved: real booking requests are messy — missing details, a flight time that doesn't line up with the requested pickup window, contradictory information. This couldn't be keyword matching. It needed to actually reason about what was missing or inconsistent and ask the right follow-up question, or it would just generate confidently wrong bookings faster than humans generated correct ones.
Solution & Architecture
A connection layer built on the whatsmeow Go library, managing the WhatsApp session directly — reading, receiving, and sending messages, read receipts, typing indicators.
On top of that, a Python multi-agent system on Google ADK:
- An orchestrator supervising the sub-agents and managing the shared context each one needs.
- A booking agent that extracts request details and fills gaps through tools — layered Google Maps queries for location resolution, flight data lookups, and the client's own backend for vehicle and driver availability, assignment, and fare estimation. When something is missing or internally contradictory, it asks a targeted follow-up instead of guessing.
- A support agent handling cancellations, modifications, rescheduling, and general inquiries against existing bookings.
A separate Flight Data service runs independently on Cloud Run as the shared flight-lookup backend the booking agent calls into.
Outcome
Turnaround dropped from ~30 minutes (2+ hours off-hours) to under a minute, with no recurring WhatsApp Business API costs, since the integration never routes through the paid official channel.
Frequently Asked Questions
How do you automate WhatsApp group messages without the official API?
By building a connection gateway layer in Go using the whatsmeow protocol library to handle session management, message reading/sending, and state indicators, paired with a Python multi-agent system for natural language reasoning.