CRDT & Sync

Realtime, multi-instance editing of a single Grida document: how two or more instances edit concurrently and converge. This is the deep study the canvas spec relies on but does not restate — replication is technical enough to warrant its own pedantic treatment.

Documents

• Durable node identity — the identity semantics a node must have for a mutation authored on one instance to mean the same thing on another.
• Sync — the replication model: the three state layers (canonical, speculative, unsent), rebase on authority order, session join/leave, presence, and exactly-once delivery. This is what makes optimistic local editing converge with remote authority.

Relationship to the editor

History is per-user and local (feat-history); sync is how remote changes interact with that local state without entering the local undo stack. The canvas spec's io and surface contracts assume this convergence model but do not define it — it lives here.