02-bash-agent

02: Bash Agent — The Expanded Bash Agent

Key Insight: One tool + proper structure = production-quality agent pattern.

What You'll Learn

• How to structure an agent with proper error handling
• The difference between interactive and subagent modes
• How process recursion implements subagents for free
• Why output truncation and timeouts matter

Prerequisites

• Completed 01: The Agent Loop
• Understand the basic agent loop

How to Run

make 02-bash-agent
# or
uv run python 02-bash-agent/agent.py

# Subagent mode (try this!)
uv run python 02-bash-agent/agent.py "list all Python files and summarize what they do"

What's New vs Noob

Feature	Noob (17 lines)	Beginner (~50 lines)
Structure	One-liner magic	Named functions, docstrings
Error handling	None	Timeouts, truncation
Modes	Interactive only	Interactive + Subagent
Comments	None	Full explanations

Key Concept: Subagent via Recursion

Main Agent
  └─ bash: python 02-bash-agent/agent.py "analyze architecture"
       └─ Subagent (isolated process, fresh history)
            ├─ bash: find . -name "*.py"
            ├─ bash: cat src/main.py
            └─ Returns summary via stdout

Process isolation = Context isolation. The subagent has no memory of the parent's conversation.

Files

File	Lines	Description
agent.py	~130	Expanded bash agent with both modes

Next Module

Ready for multiple tools? → 03: Tool Design