Behaviour Trees: Structuring AI Agents
Definition: A mathematical model for plan execution describing switching’s between finite task sets in modular fashion, popular in robotics and game development.
Why “If-Else” Isn’t Enough
For simple scripts, if-else is fine. For a complex AI agent (like an NPC in a game or a coding agent), if-else becomes spaghetti code.
Behavior Trees (BT) are a way to organize logic into “Nodes”:
- Sequence: Do A, then B, then C.
- Selector: Try A. If it fails, try B. If it fails, try C.
Vibe Coding with BTs
If you are building an AI Agent (e.g., “A bot that scrapes websites and summarizes them”), don’t write a giant while loop. Ask the AI to “Implement a Behavior Tree pattern.”
- Root: Scrape Task
- Selector: Get Content
- Sequence: Try HTTP Request -> Parse HTML.
- Sequence: Try Headless Browser -> specific selector.
- Sequence: Summarize -> Save.
- Selector: Get Content
Modular Debugging
BTs are great for Vibe Coding because they are Composable.
- Prompt: “Write the ‘Login Node’ for my Behavior Tree.”
- The AI writes a self-contained module. You plug it into the tree.
The “Vibe” of BTs
It feels like visual programming. You are designing the “Flow of Logic” rather than the syntax of control flow. It is the preferred architecture for robust Agentic AI.