The Record — Ledger and Vault

The system's critical objects refuse to be eventual. The ledger is the consistency-first persistence layer beneath them: one Repo.transaction — row locks taken FOR UPDATE, exactly-once enforced by a partial unique index, every change paired with a signed entry in an append-only ledger under the RVL brand. No transaction composer, no second idiom: the wallet — the worked instance, where the critical objects happen to be money — states the rule in its own source, and the platform holds it. Constraints back the discipline — non-negative balances checked in the schema, the revenue ledger deliberately signed.

Beneath the ledger, the deep record. Graft runs two engines under one law: the native engine on CubDB's append-only immutable B-tree — commits and pages keyed by LSN, snapshots for free — beside the Rust engine on Fjall; both speak to the same bus. The Streamer ships sealed segments to Tigris in real time and resumes from a watermark; the multi-writer fence is a conditional create — If-None-Match: "*" with X-Tigris-Consistent: true — so exactly one writer wins each LSN. Streams fold into the archive and trim; time travel reads a window by mint instant and hydrates a table. The synthesis is the vault: traces outliving the daemon's reaper under branded TRC keys, bytes verbatim, replayed through the same stores on an explicit third clock, every answer stamped with its plane.

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