# Buildprint Submission

Buildprint: Portable Durable Agent Graph Runtime.

This submission specifies a clean-room implementation target, not a LangGraph clone. `BUILDPRINT.md` is the canonical authority. The source trace in `SOURCE_TRACE.md` provides evidence for the architectural ideas. Implementation must use original code and tests written from this specification.

`Durable` here means selected checkpoint and pending-write semantics suitable for local proof and debugging. Production restart-safe storage is not claimed unless a durable storage adapter is implemented and tested.

Core deliverables:
- Typed state schema and reducer metadata.
- Builder with nodes, directed edges, conditional routing, and compile validation.
- Compiled runtime with `invoke` and `stream`.
- In-memory checkpoint saver with thread/checkpoint identity.
- Interrupt/resume via `Command`.
- Pending-write recovery simulation.
- Serializer safety gate.
- Optional local ToolNode/ReAct-style demo marked non-core.

Hard non-goals and unsafe compatibility claims are recorded in `BUILDPRINT.md` and `PARITY_CLAIMS.md`.