Agent patterns

The examples are non-trivial state machines, not special runner APIs.

Control-flow patterns

• Evaluator/optimizer
• Validate and repair (example)
• Reflection writer
• Plan and execute
• Corrective RAG
• Deep research
• Guardrails
• Hierarchical teams
• Swarm handoff
• Parallel streams

Human and long-running patterns

• Long-running onboarding
• Snapshot migration
• Review tool calls
• SQL approval
• Context compaction
• Statechart policy examples: reviewer quorum, booking compensation, and scheduler-driven approval deadlines

Host portability

The same machine artifact runs through AI SDK, Anthropic, OpenAI, LangChain, Mastra, Flue, Cloudflare, Next.js, or plain XState examples. Host adapters supply requests; they do not redefine agent control flow.

Generic orchestration such as fan-out remains ordinary XState composition.