Now we're ready to implement the backend with test-driven development.

At this point we have a domain model with diagrams, and sample data captured via headless mode.

Time to build the ingestion and query services.

Start with failing tests for message persistence and retrieval. Then let Claude cycle through the red-green TDD loop while you review each diff.

Keep API fixtures from the happy network close at hand - they'll be useful reference data as Claude builds out the functionality.