plan-and-execute

Plan-and-execute agents separate high-level planning from step-by-step execution for complex tasks. **Architecture**: Planner generates task decomposition and execution order, Executor handles individual steps, Replanner adjusts plan based on execution results. **Why separate?**: Planning requires global reasoning, execution needs local focus, separation enables specialization, easier to debug and modify. **Planning phase**: Break task into subtasks, identify dependencies, sequence execution, allocate resources/tools. **Execution phase**: Execute each step, observe results, report completion status, handle errors. **Replanning triggers**: Step failure, unexpected results, new information discovered, plan completion. **Frameworks**: LangChain Plan-and-Execute, BabyAGI, AutoGPT variants. **Example**: "Research topic and write report" → Plan: [search web, gather sources, outline, draft sections, edit] → Execute each → Replan if sources insufficient. **Advantages**: Better for complex multi-step tasks, more predictable behavior, easier oversight. **Trade-offs**: Planning overhead for simple tasks, may over-plan, requires good task decomposition ability.