# CAG Storage, Query & Privacy Architecture

# CAG Storage in Arweave

For immutable and verifiable knowledge storage, Arweave is the preferred solution due to its permanent data availability. Each fragment of the Knowledge Cache Graph (KCG)-nodes, edges, ontologies, and indices - is stored as an individual Arweave transaction (TX). Key characteristics include:

  • Each KCG object receives a unique TXID, serving as a perma-link derived from its content hash.
  • Large graphs are stored using chunked storage with CID-based linking for efficient traversal.

Example:

  • Entity Node X → Attributes file → TXID: 0xabc123.
  • Relation (X relates to Y) → Separate file → TXID: 0xdef456.
  • The entire graph is connected via an index file or JSON-LD structure with its own TXID.

Filecoin offers a similar decentralized storage model but relies on signed storage contracts (6-12 months), making it less practical for permanent knowledge preservation. Therefore, Arweave remains the primary storage layer for long-term knowledge caching.

# Fast Querying and Relationship Analysis (Graph Layer)

While Arweave and Filecoin serve as robust storage layers, efficient graph querying necessitates an additional index and query layer.

Graph Layer Architecture:

  1. Off-chain Graph Indexing:

    • Network participants (indexers) parse Arweave data using TXIDs and CIDs.
    • The graph structure is reconstructed and maintained locally using graph databases (e.g., Neo4j, TypeDB, custom RDF stores).
    • Index layers can be decentralized via IPFS/DAG protocols.
  2. Semantic Query API:

    • Provides REST or GraphQL endpoints for graph traversal, relationship queries, and semantic searches.
    • Example query: "Retrieve all relationships from Node X to Category Y within period T."

Best Practices & Tools:

  • Utilize The Graph's Subgraph architecture with Arweave Data Sources.
  • Explore OriginTrail DKG integrations with Arweave/IPFS.
  • Develop a custom micro-subgraph indexer tailored for CAG.

Caching Popular Relationships:

  • Frequently requested paths are cached by indexers.
  • Merkle Proofs ensure data freshness and integrity without needing to re-fetch from Arweave.