(1) Pass state explicitly — orchestrator collects outputs and injects relevant parts into the next agent's prompt.

(1) Pass state explicitly — orchestrator collects outputs and injects relevant parts into the next agent's prompt. (2) Shared store — agents read/write to a central state object (LangGraph StateGraph, DynamoDB, or in-memory dict). (3) Message bus — agents publish events, others subscribe. In a fund document processing system: Step Functions passes execution state between Lambda agents; DynamoDB stores intermediate results.