Graph Interoperability

The ability to execute a single query that fetches data from multiple, independent indexing networks. This eliminates the need for developers to build and maintain separate integrations for each data provider.

• Example: A dApp can query NFT ownership data from The Graph's hosted service and DeFi transaction data from a Subsquid archive in one request.
• Key Protocol: Initiatives like GraphQL Federation or cross-chain query standards enable this composability.

The use of common data models and query interfaces (like GraphQL) across different indexing protocols. This provides a consistent developer experience regardless of the underlying data source.

• Core Benefit: Developers learn one query language to access data from various networks.
• Implementation: While GraphQL is the dominant standard, interoperability efforts focus on aligning schema conventions and response formats for entities like tokens, transactions, and smart contract events.

Mechanisms to verify the origin and integrity of data as it moves between interoperable graphs. This ensures that queried data is cryptographically attested to its source blockchain.

• How it works: Uses zero-knowledge proofs or cryptographic commitments to create verifiable trails from the raw chain data to the indexed result.
• Importance: Critical for trust-minimized applications in DeFi and governance that rely on accurate, tamper-proof data.

The ability for node operators (indexers) and their staked capital to participate in multiple graph networks. This creates a shared security and economic layer for decentralized indexing.

• Economic Security: Stake portability allows indexers to allocate resources to the most in-demand data across networks, improving service quality and resilience.
• Protocol Example: The Graph's Migration Tools and cross-chain staking bridges are early steps toward this feature.

The capability to build indexing logic (subgraphs) that reference or import data from other subgraphs, even if they are deployed on different networks. This enables modular and reusable data pipelines.

• Use Case: A subgraph for a lending protocol can import price feed data from a separate oracle subgraph running on a different indexing service.
• Analogy: Similar to package managers (like npm) for blockchain data, where dependencies are clearly defined and resolved.

Shared caching layers and content delivery networks (CDNs) that serve data from multiple interoperable graphs, reducing latency and improving query performance for end-users.

• Technical Aspect: Leverages edge computing and decentralized storage to cache frequently accessed query results.
• Benefit: DApps achieve faster load times by fetching aggregated data from a geographically distributed cache rather than multiple origin servers.

A cross-chain subgraph indexes and serves data from multiple blockchain networks into a single, unified GraphQL endpoint. This is a key primitive for building applications that aggregate data across ecosystems like Ethereum, Polygon, and Arbitrum.

• How it works: A single subgraph definition is deployed with mappings for events from contracts on different chains.
• Benefit: Developers write one query to get a holistic view of a protocol's activity, regardless of the underlying chain.
• Use Case: Tracking a user's total DeFi positions across several Layer 2 networks.

This principle allows subgraphs to reference and build upon data from other subgraphs, creating a composable data layer. It enables complex queries that join data across different protocols and datasets, similar to joins in a traditional database.

• Mechanism: A subgraph can read from the entities stored by another subgraph's handler.
• Impact: Enriches data context (e.g., a lending subgraph can incorporate price feeds from an oracle subgraph).
• Standard: Facilitated by The Graph's deterministic indexing and shared storage.

Beyond a single protocol, interoperability involves standards for queries between different indexing services. Efforts like GraphQL over HTTP and shared schema conventions aim to create a common language for blockchain data access, allowing clients to switch between providers like The Graph, Goldsky, or self-hosted solutions.

• Key Standard: GraphQL's introspection allows clients to discover any graph's schema.
• Goal: Reduce vendor lock-in and increase resilience in the data layer.
• Challenge: Ensuring consistent data freshness and accuracy across different indexers.

Proof of Indexing is a cryptographic attestation that a specific Indexer has correctly processed the blockchain data for a subgraph. It is a critical cryptoeconomic primitive for decentralized interoperability, as it allows the network to verify and dispute the work of indexers, ensuring data integrity across the network.

• Function: Serves as a verifiable claim about the state of an indexed subgraph.
• Role in Interop: Provides a trust-minimized basis for cross-indexer coordination and slashing.
• Technology: Based on Merkle roots of the subgraph's database.

Gateway services act as unified entry points that route queries to the appropriate underlying indexer or subgraph, abstracting away the complexity of the decentralized network. This layer is essential for a seamless developer experience in an interoperable graph ecosystem.

• Component: The Graph's Gateway (hosted service legacy) and decentralized Query Gateway.
• Function: Load balances queries, caches responses, and manages indexer discovery.
• Analogy: Similar to a DNS system, but for locating and accessing specific blockchain datasets.

Graph interoperability allows a single dApp to query data from multiple blockchains through a unified API endpoint. This eliminates the need to manage separate indexers or subgraphs for each chain, simplifying development for multi-chain applications.

• Key Mechanism: Protocols like GraphQL and cross-chain messaging (e.g., LayerZero, Axelar) enable query routing.
• Example: A DeFi dashboard can pull liquidity data from Ethereum, transaction volume from Polygon, and user stats from Arbitrum in one request.

Developers can build subgraphs that reference events and entities from other subgraphs, even if they index different smart contracts or blockchains. This creates a composable data graph where information from one protocol can enrich another.

• Use Case: A lending protocol's subgraph on Avalanche can incorporate price feed data sourced from an Oracle subgraph on Ethereum.
• Benefit: Enables complex, cross-protocol analytics and logic without centralized data aggregation.

Interoperable graphs facilitate a marketplace where indexers can serve data for any supported blockchain, and curators can signal on subgraphs across ecosystems. This creates economic alignment and data liquidity across the entire network.

• Participants: Indexers, Curators, Delegators.
• Outcome: Higher data availability and redundancy, as indexers are incentivized to serve popular data across multiple chains.

A primary application is providing developers with a single set of tools and a consistent GraphQL schema to interact with data from any integrated blockchain. This drastically reduces the complexity of building omnichain dApps.

• Tooling: The Graph's Graph Explorer, CLI, and SDKs abstract away chain-specific data fetching complexities.
• Impact: Lowers the barrier to entry for new developers and accelerates the development of cross-chain applications.

Interoperability protocols can include mechanisms for verifying the cryptographic provenance of data as it moves between chains. This ensures that queried data maintains integrity and can be traced back to its on-chain source.

• Technology: Uses Merkle proofs and state root verification from connected blockchains.
• Importance: Critical for trust-minimized applications like cross-chain bridges and decentralized audits that rely on verified foreign-chain state.

Specific infrastructure protocols are built to solve graph interoperability challenges. These are not part of The Graph's core protocol but are complementary technologies.

• Chainlink CCIP: A cross-chain messaging protocol that could enable subgraphs to trigger or consume data from any connected chain.
• Axelar & LayerZero: General message-passing protocols that can be used to verify and request data across chains for indexing purposes.
• Wormhole: Provides attested blockchain state, which can be used as a verifiable data source for cross-chain subgraphs.