Introducing the IndexerRelayer: Graph Node powered Blockchain Attestation Oracle

A Step Towards Enhanced Blockchain Interoperability powered by the Graph Node


Usher Labs introduces the IndexerRelayer, a technology designed to enhance blockchain data indexing and verification. This system transforms a centralized Graph Node into a tool for obtaining cryptographically signed attestations of indexed data. The primary goal is to enable the data to be verified and utilized across various blockchain platforms. The IndexerRelayer, developed from prior discussions, uses a third-party validator set for real-time confirmation of blockchain events. This process ensures the reliability of attestations relayed to the destination chain. The team is dedicated to evolving this technology, focusing on notarization and proof generation methods involving RPC endpoints, aiming to minimize reliance on third-party validators, and replicated compute within these validators.


Usher Labs collaborates with the Internet Computer to pioneer a cost-effective method for transferring data from various foreign blockchains to the Internet Computer. This technology aims to leverage decentralized compute capabilities with multi-chain data, enabling innovative multi-chain outcomes. Though the motivation initially appears narrow, the broader goal is to empower any blockchain, particularly Rust-based ones, to verify foreign blockchain data using blockchain attestations. This effectively creates a Blockchain Attestation Oracle (BAO) that can be operated by protocol developers or blockchain application creators, facilitating app-specific blockchain interoperability. The IndexerRelayer is a crucial first step in this ambitious implementation.

Target Audience

The IndexerRelayer is designed for developers and teams who are actively engaged in projects focused on blockchain interoperability and are already well-versed with the Graph Node. This audience is uniquely positioned to leverage the capabilities of the IndexerRelayer, thanks to their familiarity with blockchain technologies and the specific challenges associated with data indexing and validation across multiple blockchain platforms.


The IndexerRelayer, developed by Usher Labs, is a robust solution that plays a vital role in the realm of blockchain interoperability, particularly between EVM-based blockchains and destination blockchains like ICP. This technology is meticulously designed for the following functionalities:

  1. Attestation of EVM Events: It validates Ethereum Virtual Machine events indexed by the Graph Node, ensuring their authenticity and integrity.
  2. Propagation to Destination Blockchains: After validation, these attestations are propagated to destination blockchains, such as the Internet Computer Protocol (ICP), facilitating a secure integration of events.
  3. Operational Workflow:
    • Database Connection: Securely connects to the Graph Node’s database, monitoring new events for validation.
    • Listening and Indexing: Continuously tracks new indexes from the Graph Node, ensuring up-to-date synchronization.
    • Event Validation via Log Store: Sends new indexes to the Log Store for thorough validation. Nodes within the Log Store Network scrutinize and verify each event. For a technical review of the validation program, you can refer to the Log Store Github repository.
    • Validation and Integration: Upon sufficient validations, the IndexerRelayer sends the validated events and proofs to the Protocol Data Collection Canister using the ccamp SDK. For the purposes of initial implementation, this is a very specific Smart Contract deployed to the Internet Compute.
  4. Compatibility and Evolution: Initially designed for Graph Node indexers and ICP integration, the IndexerRelayer’s architecture allows for potential expansion to support blockchains capable of verifying signed messages. As progression is made in replacing the validator set that produces ECDSA signatures that represent validated blockchain events with notarization, the process of verifying cryptographic proofs associated to indexed data will also change.
  5. Real-world Application: The IndexerRelayer is currently a key component in the Cross-Chain Asset Management Protocol (CCAMP), demonstrating its practical utility in blockchain interoperability. For more details on the CCAMP, please see the CCAMP Github repository.

This comprehensive solution, anchored in the IndexerRelayer, signifies a significant advancement in blockchain data processing, ensuring secure and verifiable data transfer across multiple blockchain platforms. For more detailed technical information, you can refer to the IndexerRelayer GitHub repository.

Next Steps

Usher Labs aims to further develop the IndexerRelayer technology with support from TheGraph Foundation and Community. The focus is on replacing the current validator set with a notarization functionality, enhancing the system’s efficiency and reliability. Additionally, there’s an open call for the community to suggest, critique, and discuss the technology, especially regarding prioritizing new blockchains for support. Community engagement is encouraged through comments on this topic or via Discord channels. This collaborative approach is intended to accelerate and enrich the development of blockchain interoperability solutions based on the Graph Node.


  1. IndexerRelayer GitHub Repository:
  2. Log Store Node for Event Validation Program:
  3. Cross-Chain Asset Management Protocol (CCAMP):
  4. Usher Labs’ Discord:
  5. Usher Labs’ Twitter:

These references provide additional technical information and insights into the components and functionalities of the IndexerRelayer, the Log Store Node for event validation, and the Cross-Chain Asset Management Protocol.