Build AI Apps with Python: AI Agent Loop — Chain Multiple Tools | Episode 10

Claude becomes an agent! In this episode, we build a while loop that lets Claude call tools repeatedly until a task is complete. No more one-call-one-answer — Claude now plans multi-step workflows on its own. Two tasks prove it works: First, Claude creates a file and reads it back to verify (2 steps). Then Claude lists files, reads each one, and writes a summary (3 steps). Claude decides the plan. You just provide the goal and the tools. Student code: https://github.com/GoCelesteAI/build-ai-apps-python/tree/main/episode10 Every keystroke is shown on screen with 3-second pauses so you can follow along at your own pace. What You'll Learn: • The agentic while True loop — runs until Claude is done • How Claude chains multiple tool calls to complete a task • Appending both assistant and tool_result messages each iteration • Claude sees its full history and decides the next step • Step counter to track how many tools Claude calls • The break pattern — Claude stops when no more tools needed • Two multi-step tasks: write+verify, list+read+summarize • Running Python scripts with :!python % Timestamps: 0:00 - Introduction 0:12 - One Call vs Many (Preview) 0:44 - Creating tool_chains.py 1:00 - Imports and setup 2:10 - Workspace directory 2:25 - File tools from Episode 9 6:35 - Save progress 6:45 - Dispatch and tool definitions 8:40 - Save definitions 8:50 - The agent function — the key concept 9:50 - while True — the agentic loop 11:30 - Tool check and dispatch 13:10 - Appending both messages — the critical step 14:15 - Step counter increment 14:25 - else break — Claude is done 15:05 - Two multi-step tasks 15:28 - Save and run 15:40 - Claude chains 2 steps, then 3 steps! 16:40 - Code review 17:00 - Recap: 3 Key Takeaways 17:32 - End Screen Key Takeaways: 1. The while loop runs until Claude stops calling tools — each iteration is one step 2. Append both assistant and tool_result messages — Claude needs its full history 3. Claude decides the plan — you give the goal and tools, it figures out the steps