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Syncraft Labs

RFC-001: CRDT vs JSON Patches Evaluation

This document summarizes the architectural evaluation of Conflict-free Replicated Data Types (CRDTs) versus JSON Patches (RFC 6902) for Syncraft Labs, originally documented in RFC-001.

Executive Summary

Section titled “Executive Summary”
Question Evaluation & Decision
Is CRDT built into Core v1.0? No (Out-of-scope for v1.0). The keyword "crdt" has been removed from @syncraft-labs/core metadata to maintain honesty with developers.
Why not embed CRDTs in Core? CRDT engines (such as Yjs or Automerge) add 50KB–80KB+ in bundle size and require complex non-standard data types. Syncraft Labs prioritizes a ~3KB lightweight footprint with native JavaScript objects.
How are conflicts handled today? Via the Pluggable Conflict Resolution engine (`conflictStrategy: “lastWriteWins”
What is the future roadmap for CRDTs? Post-v1.0, an optional external package (@syncraft-labs/crdt-adapter) will be introduced for specialized collaborative text editing use cases.

Technical Comparison

Section titled “Technical Comparison”
graph TD
  subgraph "Syncraft Labs Core Architecture"
    A["Immer Proxy Traps"] --> B["RFC 6902 JSON Patches (~3KB)"]
    B --> C["IndexedDB + Outbox Compactor"]
    C --> D["Pluggable 3-Way Merge / LWW"]
  end

  subgraph "Optional Post-v1.0 Adapter Layer"
    E["@syncraft-labs/crdt-adapter"] --> F["Yjs / Automerge Integration"]
    F --> D
  end

Trade-Off Analysis

Section titled “Trade-Off Analysis”
  1. Bundle Size:
    • JSON Patch Engine: ~3 KB (zero external dependencies).
    • Yjs / Automerge: +50 KB to +80 KB.
  2. Data Model:
    • JSON Patches operate on plain JavaScript objects, Map, and Set collections.
    • CRDTs require specialized internal data structures and tombstone cleanup algorithms.
  3. Application Coverage:
    • Over 90% of local-first mobile and web applications (forms, settings, document management, dashboards, e-commerce) are best served by lightweight operation patches + 3-way merge.
    • Rich-text collaborative canvas applications (such as Figma or Google Docs) benefit from CRDTs and can use the upcoming @syncraft-labs/crdt-adapter plugin without burdening standard applications.