A Minimal AI Agent in 50 Lines of Python (No Framework Required)

You don't need LangChain to build a useful AI agent. Here's a minimal agent in ~50 lines of Python that has memory, a defined persona, and can use tools — no framework required. The Core Loop Every agent is just a loop: Read context (who am I, what do I know) Get input (heartbeat, user message, scheduled trigger) Decide what to do Act Update memory Repeat That's it. Frameworks add abstractions on top. Sometimes that's useful. Often it's not. The Minimal Implementation import anthropic from pathlib import Path client = anthropic . Anthropic () def read_context (): """ Load agent context from workspace files. """ ctx = [] for fname in [ " SOUL.md " , " USER.md " , " MEMORY.md " , " OPS.md " ]: path = Path ( fname ) if path . exists (): ctx . append ( f " ## { fname } \n { path . read_text () } " ) return " \n\n " . join ( ctx ) def update_memory ( key , value ): """ Append a fact to today ' s daily log. """ from datetime import date log_path = Path ( f " memory/ { date . today () } .md "