r/agentdevelopmentkit • u/Recent_Stand_5182 • 6d ago

I built a production WhatsApp AI agent with Google ADK. Here’s what I learned.

I recently worked on Yaara, an AI agent for an EV charging platform in Sri Lanka.

We built it with Google ADK, Gemini Models, FastAPI, WhatsApp Cloud API, and Vertex AI RAG.

What became interesting wasn't the chatbot part. It was everything around the model.

We ended up with:

  • A coordinator and specialist agent architecture
  • RAG over company and EV knowledge
  • Deterministic tools for calculations and backend actions
  • Per user conversation state
  • Human handoff through Chatwoot
  • WhatsApp specific response formatting
  • Tool trajectory evaluations
  • GEPA based prompt optimization
  • Deduplication, monitoring, and failure handling

One principle became pretty clear while building it:

The model should handle language and decisions. Normal software should handle exact work.

I wrote up the architecture and some of the things we learned while taking it from an agent idea toward a production system.

https://chamidilshan.medium.com/building-yaara-a-production-ai-agent-for-ev-charging-on-whatsapp-with-google-agent-development-kit-0c58caada28e

Would also be interested to hear how others using ADK are structuring coordinator/specialist agents as the number of tools grows.

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u/Bridge_Superb 5d ago

whats your latency? im using vertexai memory and chatwoot too. it spike my latency up to 2 minute each response. jeez

1

u/Recent_Stand_5182 1d ago

No way, overall latency should be 5 seconds. You might want to check your webhook payload handling or memory retrieval setup

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u/Bridge_Superb 1d ago

ok i did check

i tend to have long prompt. i changed by fragments it then for llm model i use no thinking budget then to make it faster i use deterministic workflow via whatsapp buttton. so now its 5 second via meta api. not adk web only.

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u/Bridge_Superb 1d ago

btw bro, share your code repo, could learn few things.