Recipe Sync Engine

Overview

The sync engine treats every recipe as a Merkle DAG node. Changes propagate via operation-based CRDTs, ensuring offline edits merge without central coordination. Each client holds a partial replica and gossips state vectors on reconnect.

Core Primitives

• OpLog — append-only journal of insert, update, and delete operations keyed by Lamport timestamp.
• State Vector — compact map of peer ID to last-seen sequence number; exchanged during handshake to compute delta.
• Content Hash — SHA-256 of the normalized recipe body; deduplicates identical nodes across peers.

Merge Strategy

Concurrent edits to the same field resolve via last-writer-wins with a tiebreaker on node ID. Structural conflicts — such as deleting a parent while a child is inserted — are detected through causal stability checks before applying operations.

Transport Layer

Sync payloads travel over WebSocket with a thin framing header: message type, compressed op batch, and sender state vector. The server acts as a stateless relay; all conflict resolution happens client-side.