Indexing Moonbeam with Subsquid¶

Introduction¶

Subsquid is a data network that allows rapid and cost-efficient retrieval of blockchain data from 100+ chains using Subsquid’s decentralized data lake and open-source SDK. 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 Moonbeam 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 Moonbeam 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 quick-start guide will show you how to create Substrate and EVM projects with Subsquid and configure it to index data on Moonbeam. For a more comprehensive end-to-end tutorial, be sure to check out Index a Local Moonbeam Development Node with Subsquid.

Checking Prerequisites¶

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

• Node.js version 16 or newer
• Docker
• Squid CLI

Index Substrate Data on Moonbeam¶

To get started indexing Substrate data on Moonbeam, you'll need to create a Subsquid project and configure it for Moonbeam 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. Navigate into the root directory of your Squid project and install dependencies by running:

   npm ci
   

3. To configure your Subsquid project to run on Moonbeam, 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:

   MoonbeamMoonriverMoonbase Alpha

   "specVersions": "https://v2.archive.subsquid.io/metadata/moonbeam",
   

   "specVersions": "https://v2.archive.subsquid.io/metadata/moonriver",
   

   "specVersions": "https://v2.archive.subsquid.io/metadata/moonbase",
   

4. 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:

   MoonbeamMoonriverMoonbase Alpha

   const processor = new SubstrateBatchProcessor();
   processor.setDataSource({
     chain: 'INSERT_RPC_API_ENDPOINT',
     // Resolves to 'https://v2.archive.subsquid.io/network/moonbeam-mainnet'
     archive: lookupArchive('moonbeam', {type: 'Substrate', release: 'ArrowSquid'}),
   })
   

   const processor = new SubstrateBatchProcessor();
   processor.setDataSource({
     chain: 'INSERT_RPC_API_ENDPOINT',
     // Resolves to 'https://v2.archive.subsquid.io/network/moonriver-mainnet'
     archive: lookupArchive('moonriver', {type: 'Substrate', release: 'ArrowSquid'}),
   })
   

   const processor = new SubstrateBatchProcessor();
   processor.setDataSource({
     chain: 'https://rpc.api.moonbase.moonbeam.network',
     // Resolves to 'https://v2.archive.subsquid.io/network/moonbase-testnet'
     archive: lookupArchive('moonbase', {type: 'Substrate', release: 'ArrowSquid'}),
   })
   

   Note

   To configure your project for Moonbeam or Moonriver, you will need to have your own endpoint and API key, which you can get from one of the supported Endpoint Providers.

5. There's one more quick change to make to the template. The Subsquid Substrate template is configured to process Substrate account types, but Moonbeam uses Ethereum-style accounts. The getTransferEvents function in the src/main.ts file will iterate through the events ingested by processor.ts and store the relevant transfer events in the database. In the getTransferEvents function, remove the ss58 encoding of the from and to fields. In an unmodified Substrate template, the from and to fields are ss58 encoded as shown:

   from: ss58.codec('kusama').encode(rec.from),
   to: ss58.codec('kusama').encode(rec.to),
   

   After removing the ss58 encoding, the respective lines are:

   from: rec.from, 
   to: rec.to, 
   

And that's all you have to do to configure your Subsquid project to index Substrate data on Moonbeam! Now you can update the schema.graphql, typegen.json, src/main.ts, and src/processor.ts files to index the data you need for your project! Next, take the steps in the Run your Indexer section to run your indexer and query your Squid.

Index Ethereum Data on Moonbeam¶

To get started indexing EVM data on Moonbeam, you'll need to create a Subsquid project and configure it for Moonbeam 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:

   EVMABI

   sqd init INSERT_SQUID_NAME --template evm
   

   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:

   • Quickstart: EVM chains
   • Quickstart: generate from ABI

2. Navigate into the root directory of your Squid project and install dependencies by running:

   npm ci
   

3. 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:

   MoonbeamMoonriverMoonbase Alpha

   const processor = new EvmBatchProcessor();
   processor.setDataSource({
     chain: 'INSERT_RPC_API_ENDPOINT',
     // Resolves to 'https://v2.archive.subsquid.io/network/moonbeam-mainnet'
     archive: lookupArchive('moonbeam', { type: 'EVM' })
   })
   

   const processor = new EvmBatchProcessor();
   processor.setDataSource({
     chain: 'INSERT_RPC_API_ENDPOINT',
     // Resolves to 'https://v2.archive.subsquid.io/network/moonriver-mainnet'
     archive: lookupArchive('moonriver', { type: 'EVM' }),
   })
   

   const processor = new EvmBatchProcessor();
   processor.setDataSource({
     chain: 'https://rpc.api.moonbase.moonbeam.network',
     // Resolves to 'https://v2.archive.subsquid.io/network/moonbase-testnet'
     archive: lookupArchive('moonbase', { type: 'EVM' }),
   })
   

   Note

   To configure your project for Moonbeam or Moonriver, you will need to have your own endpoint and API key, which you can get from one of the supported Endpoint Providers.

And that's all you have to do to configure your Subsquid project to index EVM data on Moonbeam! Now you can update the schema.graphql, src/main.ts, and src/processor.ts files to index the data you need for your project! Continue with the steps in the following section to run your indexer and query your Squid.

Run Your Indexer¶

These steps apply to both Substrate and EVM indexers. Running your Subsquid indexer after you've properly configured it takes only a few steps:

1. Launch Postgres by running:

   sqd up
   

2. Inspect and run the processor:

   sqd process
   

3. Open a separate terminal window in the same directory, then start the GraphQL server:

   sqd serve
   

4. You can query your template Substrate or EVM Squid with the below sample queries. If you've modified the template Squid to index different data, you'll need to modify this query accordingly

   Substrate IndexerEVM Indexer

   query MyQuery {
     accountsConnection(orderBy: id_ASC) {
       totalCount
     }
   }
   

   query MyQuery {
     burns(orderBy: value_DESC) {
       address
       block
       id
       txHash
       value
     }
   }
   

If you're interested in a step-by-step tutorial to get started indexing data on Moonbeam, you can check out the Index NFT Token Transfers on Moonbeam with Subsquid tutorial!