gRPC, without a second toolchain
AAT v0.3.0 runs gRPC. The interesting part is what it did not add: no second plan format, no second runner, no second archive viewer, and nothing new to learn if you already have a project. A graph node names a method instead of a path, a template sends a message instead of a body, and everything downstream — the wiring between steps, the assertions, the retries, the cleanup, the archive, the web UI, the MCP server — carries on as though nothing had happened.