Everyone's talking about AI agents, but most tutorials start with heavyweight frameworks, API keys, and 500+ lines of boilerplate. What if you could build a functional AI agent in just 60 lines of pure Python? No LangChain. No CrewAI. No framework at all. Let's do it. What We're Building A simple AI agent that can: Take a goal as input Break it into subtasks Execute each subtask using tools Return a final result Think of it as the minimal viable agent — the skeleton you can extend into anything. The Architecture Our agent follows the classic Observe → Think → Act loop: ┌─────────────┐ │ USER GOAL │ └──────┬──────┘ │ ▼ ┌──────────────┐ │ THINK (LLM) │◄──────┐ └──────┬───────┘ │ │ │ ▼ │ ┌──────────────┐ │ │ ACT (Tool) │───────┘ └──────┬───────┘ │ ▼ ┌──────────────┐ │ RESULT │ └──────────────┘ Enter fullscreen mode Exit fullscreen mode The Code (60 Lines) import json import os from anthropic import Anthropic client = Anthropic () # Define tools the agent can use tools = [ { " name " : " calculator " , "…