ADR 0005: The query is the subscription

Status: accepted (2026-09-09)

"live": true keeps a query open. The server records the read set (entity keys + reachable entity types), re-runs on intersecting changes from the change bus (fed by command patches and adapters), diffs, and sends a minimal patch or a fresh data frame. Type-level intersection is deliberately conservative; adapters may narrow it but must not change frame meaning.

Alternatives rejected: a separate subscription type with hand-written publishers (GraphQL), and database-coupled sync engines (vendor lock-in).