04Voice AI - Vapi + n8n
ManoExperta Voice Agent
A production-style phone agent for a maintenance company: gives safe technical guidance from a knowledge base and books, reschedules and cancels appointments end to end.
Vapin8nPineconePostgresGoogle CalendarTelegram
The problem
Staffing a maintenance phone line 24/7 is expensive and inconsistent. The agent must triage issues, advise safely, and manage appointments without ever confirming a booking the system didn't actually commit.
What it proves
Building a stateful, tool-using voice agent backed by correctness-critical logic: a DB concurrency lock, calendar sync, and a fault-tolerance layer that keeps the call alive.
Architecture
- 1.Vapi handles speech and tool calling, driven by a strict system prompt
- 2.n8n receives tool-call webhooks and routes them (RAG vs appointment actions)
- 3.consultar_manual_rag retrieves safe procedures from Pinecone (Gemini embeddings)
- 4.gestionar_agenda_db books with an ON CONFLICT slot lock + Google Calendar sync
- 5.Every external call has a controlled fallback, plus error logging and Telegram alerts
Architecture diagram
Engineering highlights
- +Anti-double-booking via a Postgres ON CONFLICT lock
- +Book-before-cancel reschedule so a client is never left without an appointment
- +Full fault-tolerance layer: controlled spoken fallbacks + structured audit logs
- +Returning callers recognized automatically by phone number
Demo
Demo: a call that gives a safe tip, books a visit, then cancels it on a callback.
Demo recording placeholder (add a Loom link or demo.gif)