Planner
The agent component that breaks down high-level goals into executable steps.
Why it matters
Complex tasks need breaking into steps. The planner figures out what needs to happen before the executor starts.
In practice
When Claude Code receives 'build a glossary system', the planner breaks it into: data structure, index page, detail pages, translations, navigation, sitemap.
Related terms
Executor
The agent component that carries out planned actions by invoking tools, APIs, or workflows.
Task Decomposition
Breaking a complex task into smaller, manageable subtasks.
ReAct Pattern
Agent action model: Reason, Act, Observe, Repeat.
Agent (AI Agent)
An AI system that plans, decides, and acts autonomously toward goals, rather than simply responding to prompts.