I built a fully autonomous AI agent that costs $0/month to run. Here is exactly how.
The Problem: API Bills Add Up
When you build an AI agent, the first thing you reach for is an API: OpenAI, DeepSeek, Groq. They work great — until you check the bill. Even at $0.14/million tokens, a moderately active agent burns through $30-50/month. That is a GPU you will never save up for.
The second problem: most conversations do not need a frontier model. When a customer asks "How much is wedding photography?", you do not need GPT-5. You need a FAQ lookup + a friendly reply. Yet API pricing charges the same rate whether you are writing a novel or answering "What are your hours?"
I wanted something better. So I hacked together a stack that runs completely free:
