Eino Compose

This covers the Eino orchestration layer when you need to wire up multi-step pipelines in Go. You get three APIs: Chain for linear flows, Graph for anything with branches or cycles (like ReAct agents), and Workflow for DAGs where you need fine-grained field mapping between different struct types. All three compile down to the same Runnable abstraction with invoke, stream, collect, and transform modes. The framework auto-converts between streaming and non-streaming nodes, which is genuinely convenient. Most real work happens in Graph since branching and state management are table stakes for agents. The reference docs include a complete ReAct example with tool calling and checkpointing, so you're not starting cold.