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What is Ara?

Ara is a delay-tolerant, offline-first mesh sync SDK for any application that needs shared state without reliable connectivity. It provides conflict-free, eventually-consistent state across nodes communicating over heterogeneous transports — UDP LAN, LoRa mesh, and MQTT — with graceful degradation when links go down.

How it works​

┌─────────────────────────────────────────────────────────────┐
│                        Application                           │
│              (UI / dashboard / Android / Go)                 │
├─────────────────────────────────────────────────────────────┤
│                       Ara SDK                                │
│         Open · Exec · Query · Peers · IngestBlob            │
├───────────────────────┬─────────────────────────────────────┤
│    Sync Engine        │        Blob Store                    │
│  handshake → delta   │  content-addressed (SHA-256)        │
│  send → merge         │  resumable transfer                  │
├───────────────────────┴─────────────────────────────────────┤
│                  Transport Manager                           │
│          priority fallback · dedup · payload limit            │
├──────────────┬──────────────────┬───────────────────────────┤
│  UDP LAN     │   LoRa / Meshtastic │   MQTT                 │
│              │   220 B packets     │   WiFi/cellular        │
├──────────────┴──────────────────┴───────────────────────────┤
│                     CRDT merge engine                         │
│        Last-Writer-Wins per column · vector clock delta        │
├─────────────────────────────────────────────────────────────┤
│                    SQLite (local store)                      │
└─────────────────────────────────────────────────────────────┘

Key properties​

  • Offline-first — every node has a full local copy; reads and writes work without network
  • CRDT merge — conflicts resolve automatically via Last-Writer-Wins per column
  • Vector clock delta sync — only changes the peer is missing are transmitted
  • Schema migrations — additive-only, version negotiated on peer handshake
  • Transport-agnostic — pluggable transports; engine degrades to best available link
  • Blob transfer — content-addressed store with resumable byte delivery via a TCP sidecar alongside UDP sync

Next steps​