Tutorial: Set Up a Substreams-Powered Subgraph on Solana

Reading time: 3 min

Before starting, make sure to:

• Complete the Getting Started Guide to set up your development environment using a Dev Container.
• Be familiar with The Graph and basic blockchain concepts such as transactions and Protobufs.

1. Open your Dev Container and run the following command to initialize your project:

   substreams init
   

2. Select the "minimal" project option.

3. Replace the contents of the generated substreams.yaml file with the following configuration, which filters transactions for the Orca account on the SPL token program ID:

specVersion: v0.1.0
package:
  name: my_project_sol
  version: v0.1.0

imports: # Pass your spkg of interest
  solana: https://github.com/streamingfast/substreams-solana-spl-token/raw/master/tokens/solana-spl-token-v0.1.0.spkg

modules:
  - name: map_spl_transfers
    use: solana:map_block # Select corresponding modules available within your spkg
    initialBlock: 260000082

  - name: map_transactions_by_programid
    use: solana:solana:transactions_by_programid_without_votes

network: solana-mainnet-beta

params: # Modify the param fields to meet your needs
  # For program_id: TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA
  map_spl_transfers: token_contract:orcaEKTdK7LKz57vaAYr9QeNsVEPfiu6QeMU1kektZE

Once the project is initialized, generate a subgraph manifest by running the following command in the Dev Container:

substreams codegen subgraph

You will generate asubgraph.yaml manifest which imports the Substreams package as a data source:

---
dataSources:
  - kind: substreams
    name: my_project_sol
    network: solana-mainnet-beta
    source:
      package:
        moduleName: map_spl_transfers # Module defined in the substreams.yaml
        file: ./my-project-sol-v0.1.0.spkg
    mapping:
      apiVersion: 0.0.7
      kind: substreams/graph-entities
      file: ./src/mappings.ts
      handler: handleTriggers

Define the fields you want to save in your subgraph entities by updating the schema.graphql file. Here is an example:

type MyTransfer @entity {
  id: ID!
  amount: String!
  source: String!
  designation: String!
  signers: [String!]!
}

This schema defines a MyTransfer entity with fields such as id, amount, source, designation, and signers.

With the Protobuf objects generated, you can now handle the decoded Substreams data in your mappings.ts file found in the ./src directory. The example below demonstrates how to extract to subgraph entities the non-derived transfers associated to the Orca account id:

import { Protobuf } from 'as-proto/assembly'
import { Events as protoEvents } from './pb/sf/solana/spl/token/v1/Events'
import { MyTransfer } from '../generated/schema'

export function handleTriggers(bytes: Uint8Array): void {
  const input: protoEvents = Protobuf.decode<protoEvents>(bytes, protoEvents.decode)

  for (let i = 0; i < input.data.length; i++) {
    const event = input.data[i]

    if (event.transfer != null) {
      let entity_id: string = `${event.txnId}-${i}`
      const entity = new MyTransfer(entity_id)
      entity.amount = event.transfer!.instruction!.amount.toString()
      entity.source = event.transfer!.accounts!.source
      entity.designation = event.transfer!.accounts!.destination

      if (event.transfer!.accounts!.signer!.single != null) {
        entity.signers = [event.transfer!.accounts!.signer!.single!.signer]
      } else if (event.transfer!.accounts!.signer!.multisig != null) {
        entity.signers = event.transfer!.accounts!.signer!.multisig!.signers
      }
      entity.save()
    }
  }
}

To generate Protobuf objects in AssemblyScript, run the following command:

npm run protogen

This command converts the Protobuf definitions into AssemblyScript, allowing you to use them in the subgraph's handler.

You’ve successfully set up a trigger-based Substreams-powered subgraph for a Solana SPL token. You can now further customize your schema, mappings, and modules to suit your specific use case.

For more advanced customization and optimizations, check out the official Substreams documentation.