Skip to main content

Indexing Elysium with Subsquid

Subsquid is a query node framework for Substrate-based blockchains. In very simple terms, Subsquid can be thought of as an ETL (extract, transform, and load) tool with a GraphQL server included. It enables comprehensive filtering, pagination, and even full-text search capabilities.

Subsquid has native and full support for both Ethereum Virtual Machine (EVM) and Substrate data. Since Elysium is a Substrate-based smart contact platform that is EVM-compatible, Subsquid can be used to index both EVM and Substrate-based data. Subsquid offers a Substrate Archive and Processor and an EVM Archive and Processor. The Substrate Archive and Processor can be used to index both Substrate and EVM data. This allows developers to extract on-chain data from any of the Elysium networks and process EVM logs as well as Substrate entities (events, extrinsics, and storage items) in one single project and serve the resulting data with one single GraphQL endpoint. If you exclusively want to index EVM data, it is recommended to use the EVM Archive and Processor.

This guide will show you how to create Substrate and EVM projects with Subsquid and configure it to index data on Elysium.

Checking Prerequisites​

To get started with Subsquid, you'll need to have the following:

NOTE: The squid template is not compatible with yarn, so you'll need to use npm instead.

Index Substrate Data on Elysium​

To get started indexing Substrate data on Elysium, you'll need to create a Subsquid project and configure it for Elysium by taking the following steps:

  1. Create a Subsquid project based on the Substrate template by running:

    sqd init <insert-squid-name> --template substrate

    For more information on getting started with this template, please check out the Quickstart: Substrate chains guide on Subsquid's documentation site.

  2. To configure your Subsquid project to run on Elysium, you'll need to update the typegen.json file. The typegen.json file is responsible for generating TypeScript interface classes for your data. Depending on the network you're indexing data on, the specVersions value in the typegen.json file should be configured as follows:

Elysium​

"specVersions": "https://Elysium.archive.subsquid.io/graphql",
  1. Modify the src/processor.ts file, which is where squids instantiate the processor, configure it, and attach handler functions. The processor fetches historical on-chain data from an Archive, which is a specialized data lake. You'll need to configure your processor to pull data from the Archive that corresponds to the network you are indexing data on:

Elysium​

const processor = new SubstrateBatchProcessor();
processor.setDataSource({
    chain: '{{ networks.elysium.rpc_url }}',
    archive: lookupArchive("elysium", {type: "firesquid"}),
});

And that's all you have to do to configure your Subsquid project to index Substrate data on Elysium! Now you can update the schema.graphql, typgen.json, and src/processor.ts files to index the data you need for your project!

Index Ethereum Data on Elysium​

To get started indexing EVM data on Elysium, you'll need to create a Subsquid project and configure it for Elysium by taking the following steps:

  1. You can create a Subsquid project for EVM data by using the generic EVM template or you can use the ABI template for indexing data related to a specific contract:

    === "EVM"

    sqd init <insert-squid-name> --template evm

    === "ABI"

    sqd init <insert-squid-name> --template abi

    For more information on getting started with both of these templates, please check out the following Subsquid docs:

  2. To configure your Subsquid project to run on Elysium, you'll need to update the typegen.json file. The typegen.json file is responsible for generating TypeScript interface classes for your data. Depending on the network you're indexing data on, the specVersions value in the typegen.json file should be configured as follows:

Elysium​

"specVersions": "https://elysium.archive.subsquid.io/graphql",
  1. Modify the src/processor.ts file, which is where squids instantiate the processor, configure it, and attach handler functions. The processor fetches historical on-chain data from an Archive, which is a specialized data lake. You'll need to configure your processor to pull data from the Archive that corresponds to the network you are indexing data on:

Elysium​

   const processor = new EvmBatchProcessor();
processor.setDataSource({
    chain: '{{ networks.Elysium.rpc_url }}',
    // Resolves to "https://Elysium-evm.archive.subsquid.io"
    archive: lookupArchive("elysium", {type: "EVM"})
});

And that's all you have to do to configure your Subsquid project to index EVM data on Elysium! Now you can update the schema.graphql, typgen.json, and src/processor.ts files to index the data you need for your project!