How I Built an AI Voice Agent with Service Area Validation (Retell AI + n8n + Python)

Description

After 20 years in insurance call centers, I'm learning to build AI voice agents - and documenting everything. This is my first tutorial showing exactly how I built a service area validation function that: Takes an address from a conversation Geocodes and validates it Calculates distance from business location Returns approval or denial to the AI agent Tools used: Retell AI (voice agent platform) n8n (workflow automation) Python (custom logic) Nominatim/OpenStreetMap (geocoding) Claude (prompt engineering) What you'll learn: How to connect Retell AI to custom functions Using n8n webhooks with Python code nodes Address validation and distance calculations Why I switched from visual workflows to code Did AI write this code? No. I copy/pasted it from Stack Overflow like a proper developer. Background: I helped implement IVR systems back in 2005. Now AI can handle full conversations. So I'm learning to build the technology that's changing my industry. Daily shorts + weekly tutorials documenting the journey. Subscribe if you're learning AI, facing automation in your career, or just want to see someone figure this out in real-time. Next video: Building appointment booking with automatic travel time calculations. #AI #VoiceAI #RetellAI #n8n #Python #Tutorial #Automation