Decision
ADR 0004: Har is a contract before a fork
Require demonstrated incompatibility before owning database infrastructure.
acceptedfilesystempre.page.v1
Context
Instant's open-source realtime relational model appears close to Pre's needs, and a Pre-native fork could be named Har.
Decision
Har first names the Pre-facing source, query, relation, permission, event, sync, and export contracts. Instant may implement those contracts through an adapter.
A code fork occurs only after a real vertical slice proves a material requirement cannot reasonably live above Instant.
Consequences
- The architecture is not prematurely coupled to a fork.
- Real requirements determine infrastructure ownership.
- HARnest, Presertion, Stow, and the CLI target Har contracts rather than Instant-specific assumptions.