Building StareBrain, Part 21: Natural Language Planning — Turning a Raw Instruction into an AgentTask

Parts 1–20 built the execution engine. We've covered how StareBrain runs tasks, handles failures, manages context, and resumes across sessions. Today we go one layer up: how a raw user instruction becomes an AgentTask with concrete AgentStep s before any execution begins.

This is the planning layer.

The Problem

A user says: "Order the same thing I got last time."

That's not a task. It's an intent. Before StareBrain can execute anything, it needs to decompose this into steps — open the app, find the last order, reorder it, confirm payment.…