Avalanche Quick Start - Crabada NFTs

SubQuery TeamAbout 4 min

Avalanche Quick Start - Crabada NFTs

The goal of this quick start guide is to index all Crabada NFTs on Avalanche's C-chain.

In the earlier Quickstart section , you should have taken note of three crucial files. To initiate the setup of a project from scratch, you can proceed to follow the steps outlined in the initialisation description.

As a prerequisite, you will need to generate types from the ABI files of each smart contract. Additionally, you can kickstart your project by using the EVM Scaffolding approach (detailed here). You'll find all the relevant events to be scaffolded in the documentation for each type of smart contract.

Note

The final code of this project can be found here.

Your Project Manifest File

The Project Manifest file is an entry point to your project. It defines most of the details on how SubQuery will index and transform the chain data.

For EVM chains, there are three types of mapping handlers (and you can have more than one in each project):

BlockHanders: On each and every block, run a mapping function
TransactionHandlers: On each and every transaction that matches optional filter criteria, run a mapping function
LogHanders: On each and every log that matches optional filter criteria, run a mapping function

Important

We use Ethereum packages, runtimes, and handlers (e.g. @subql/node-ethereum, ethereum/Runtime, and ethereum/*Handler) for Avalanche. Since Avalanche's C-chain is built on Ethereum's EVM, we can use the core Ethereum framework to index it.

We are indexing actions from the Crabada NFT contract, first you will need to import the contract abi defintion from https://snowtrace.io/address/0xe48b3a0dc82be39bba7b895c9ff1d788a54edc47#code. You can copy the entire JSON and save as a file ./abis/crabada.json in the root directory.

This section in the Project Manifest now imports all the correct definitions and lists the triggers that we look for on the blockchain when indexing.

Since you are going to index all Crabada NFTs, you need to update the datasources section as follows:

{
  dataSources: [
    {
      kind: EthereumDatasourceKind.Runtime,
      // First mint https://snowtrace.io/tx/0x17336f3699f922c245663a50fba2d857c368f6c8137024b980cc2e7042e4df87
      startBlock: 30128346,
      options: {
        // Must be a key of assets
        abi: "crabada",
        // Crabada Legacy Contract https://snowtrace.io/address/0xCB7569a6Fe3843c32512d4F3AB35eAE65bd1D50c
        address: "0xCB7569a6Fe3843c32512d4F3AB35eAE65bd1D50c",
      },
      assets: new Map([["erc20", { file: "./abis/crabada.json" }]]),
      mapping: {
        file: "./dist/index.js",
        handlers: [
          {
            kind: EthereumHandlerKind.Event,
            handler: "handleERC721",
            filter: {
              topics: ["Transfer(address from, address to, uint256 tokenId)"],
            },
          },
          {
            kind: EthereumHandlerKind.Event,
            handler: "handleNewCrab",
            filter: {
              topics: [
                "NewCrab(address account, uint256 id, uint256 daddyId, uint256 mommyId, uint256 dna, uint64 birthday, uint8 breedingCount)\n",
              ],
            },
          },
        ],
      },
    },
  ],
}

The above code indicates that you will be running a handleNewCrab mapping function whenever there is an NewCrab log on any transaction from the Crabada Legacy Contract.

Additionally, whenever there is a Transfer log that relates to any token from the Crabada Legacy Contract, we run a handleERC721 mapping function.

Check out our Manifest File documentation to get more information about the Project Manifest (project.ts) file.

Update Your GraphQL Schema File

The schema.graphql file determines the shape of your data from SubQuery due to the mechanism of the GraphQL query language. Hence, updating the GraphQL Schema file is the perfect place to start. It allows you to define your end goal right at the start.

Remove all existing entities and update the schema.graphql file as follows. Here you can see we are indexing three entities, a Deposit and a Withdrawl each with a foreign key relationship to the User.

type Crab @entity {
  id: ID!
  address: Address!
  daddy: Crab
  mommy: Crab
  dna: BigInt
  birthday: BigInt
  breeding_count: Int
  minted_block: BigInt! # Should be bigInt
  minted_timestamp: BigInt! # unix epoch timestamp
  minter_address: Address! # event transaction from
  current_owner: Address! # event args to
  metadata_url: String
}

type Transfer @entity {
  id: ID!
  tokenId: String!
  block: BigInt
  timestamp: BigInt
  transaction_hash: String # event transaction hash
  crab: Crab
  from: Address!
  to: Address!
}

type Address @entity {
  id: ID! # Address?
}

Note

Importantly, these relationships can not only establish one-to-many connections but also extend to include many-to-many associations. To delve deeper into entity relationships, you can refer to this section. If you prefer a more example-based approach, our dedicated Hero Course Module can provide further insights.

SubQuery simplifies and ensures type-safety when working with GraphQL entities, smart contracts, events, transactions, and logs. The SubQuery CLI will generate types based on your project's GraphQL schema and any contract ABIs included in the data sources.

yarn

yarn codegen

npm

npm run-script codegen

This action will generate a new directory (or update the existing one) named src/types. Inside this directory, you will find automatically generated entity classes corresponding to each type defined in your schema.graphql. These classes facilitate type-safe operations for loading, reading, and writing entity fields. You can learn more about this process in the GraphQL Schema section.

It will also generate a class for every contract event, offering convenient access to event parameters, as well as information about the block and transaction from which the event originated. You can find detailed information on how this is achieved in the EVM Codegen from ABIs section. All of these types are stored in the src/types/abi-interfaces and src/types/contracts directories.

You can conveniently import all these types:

import { Crab, Transfer, Address } from "../types";
import { NewCrabLog, TransferLog } from "../types/abi-interfaces/Crabada";

Check out the GraphQL Schema documentation to get in-depth information on schema.graphql file.

Now that you have made essential changes to the GraphQL Schema file, let’s proceed ahead with the Mapping Function’s configuration.

Add a Mapping Function

Mapping functions define how blockchain data is transformed into the optimised GraphQL entities that we previously defined in the schema.graphql file.

Follow these steps to add a mapping function:

Navigate to the default mapping function in the src/mappings directory. You will be able to see three exported functions: handleBlock, handleLog, and handleTransaction. Replace these functions with the following code (note the additional imports):

import assert from "assert";
import { Crab, Transfer, Address } from "../types";
import { NewCrabLog, TransferLog } from "../types/abi-interfaces/Crabada";
import { Crabada__factory } from "../types/contracts/factories/Crabada__factory";

async function checkCreateAddress(id: string): Promise<Address> {
  let address = await Address.get(id.toLowerCase());
  if (!address) {
    address = Address.create({
      id: id.toLowerCase(),
    });
    await address.save();
  }
  return address;
}

export async function handleNewCrab(newCrabLog: NewCrabLog): Promise<void> {
  logger.info(
    "encountered New Crab Log on block " + newCrabLog.blockNumber.toString(),
  );
  // Process remainder
  assert(newCrabLog.args, "Requires args");
  const erc721Instance = Crabada__factory.connect(newCrabLog.address, api);
  const account = await checkCreateAddress(newCrabLog.args.account);
  const daddy = await Crab.get(newCrabLog.args.daddyId.toString());
  const mommy = await Crab.get(newCrabLog.args.mommyId.toString());
  const minterAddress = await checkCreateAddress(newCrabLog.transaction.from);

  let metadataUri;
  try {
    // metadata possibly undefined
    // nft can share same metadata
    // if collection.name and symbol exist, meaning there is metadata on this contract
    metadataUri = await erc721Instance.tokenURI(newCrabLog.args.id);
  } catch (e) {}

  let crab = await Crab.get(newCrabLog.args.id.toString());
  // Reset crab with new data
  crab = Crab.create({
    id: newCrabLog.args.id.toString(),
    addressId: account.id,
    daddyId: daddy?.id,
    mommyId: mommy?.id,
    dna: newCrabLog.args.dna.toBigInt(),
    birthday: newCrabLog.args.birthday.toBigInt(),
    breeding_count: newCrabLog.args.breedingCount,
    minted_block: BigInt(newCrabLog.blockNumber),
    minted_timestamp: newCrabLog.block.timestamp,
    minter_addressId: minterAddress.id,
    current_ownerId: account.id,
    metadata_url: metadataUri,
  });

  await crab.save();
}

export async function handleERC721(transferLog: TransferLog): Promise<void> {
  logger.info(
    "encountered crabada transfer on block " +
      transferLog.blockNumber.toString(),
  );

  assert(transferLog.args, "No event args on erc721");

  const nftId = transferLog.args.tokenId.toString();
  const fromAddress = await checkCreateAddress(transferLog.args.from);
  const toAddress = await checkCreateAddress(transferLog.args.to);

  let crab = await Crab.get(nftId);
  if (crab) {
    logger.info(`We have seen crab ${nftId} before`);
  } else {
    logger.info(`We have not seen crab ${nftId} before`);
    const account = await checkCreateAddress(transferLog.address.toLowerCase());
    const minterAddress = await checkCreateAddress(
      transferLog.transaction.from,
    );
    // We create a minimal version so we can proceed
    crab = Crab.create({
      id: nftId,
      addressId: account.id,
      minted_block: BigInt(transferLog.blockNumber),
      minted_timestamp: transferLog.block.timestamp,
      minter_addressId: minterAddress.id,
      current_ownerId: toAddress.id,
    });
    await crab.save();
  }

  // Create the transfer record
  const transfer = Transfer.create({
    id: `${transferLog.transactionHash}-${transferLog.logIndex.toString()}`,
    tokenId: transferLog.args.tokenId.toString(),
    block: BigInt(transferLog.blockNumber),
    timestamp: transferLog.block.timestamp,
    transaction_hash: transferLog.transactionHash,
    crabId: crab.id,
    fromId: fromAddress.id,
    toId: toAddress.id,
  });

  await transfer.save();
}

Let’s understand how the above code works.

For the handleNewCrab mapping function, it receives a NewCrabLog which includes the transaction log data in the payload (it's autogenerated from the ABI definitions). We extract this data the instantiate a new erc721Instance ethers API to allow us to make contract calls for metadata URIs. Then we retrieve the account, daddy, mommy, and minterAddress from the crabs provided. We then attempt to get the existing grab, and update it with the new data relating to it before saving this to the store using the .save() function (Note that SubQuery will automatically save this to the database).

In handleERC721, we recieve a TransferLog from the token transfer, and then retrieve the nftId, fromAddress, and toAddress from it. After checking that we have a Crab entity (and creating one if not), we then create a new Transfer entity that we defined in our schema.graphql and then save this to the store using the .save() function (Note that SubQuery will automatically save this to the database).

Check out our Mappings documentation to get more information about the Project Manifest (project.ts) file.

Build Your Project

Next, build your work to run your new SubQuery project. Run the build command from the project's root directory as given here:

yarn

yarn build

npm

npm run-script build

Important

Whenever you make changes to your mapping functions, you must rebuild your project.

Now, you are ready to run your first SubQuery project. Let’s check out the process of running your project in detail.

Whenever you create a new SubQuery Project, first, you must run it locally on your computer and test it and using Docker is the easiest and quickiest way to do this.

Run Your Project Locally with Docker

The docker-compose.yml file defines all the configurations that control how a SubQuery node runs. For a new project, which you have just initialised, you won't need to change anything.

However, visit the Running SubQuery Locally to get more information on the file and the settings.

Run the following command under the project directory:

yarn

yarn start:docker

npm

npm run-script start:docker

Note

It may take a few minutes to download the required images and start the various nodes and Postgres databases.

Query your Project

Next, let's query our project. Follow these three simple steps to query your SubQuery project:

Open your browser and head to http://localhost:3000.
You will see a GraphQL playground in the browser and the schemas which are ready to query.
Find the Docs tab on the right side of the playground which should open a documentation drawer. This documentation is automatically generated and it helps you find what entities and methods you can query.

Try the following queries to understand how it works for your new SubQuery starter project. Don’t forget to learn more about the GraphQL Query language.

query {
  crabs(first: 5, orderBy: MINTED_BLOCK_DESC) {
    totalCount
    nodes {
      id
      addressId
      daddyId
      mommyId
      dna
      birthday
      breedingCount
      mintedBlock
      mintedTimestamp
      currentOwnerId
      minterAddressId
      metadataUrl
      transfers(first: 5, orderBy: BLOCK_DESC) {
        totalCount
        nodes {
          transactionHash
          block
          crabId
        }
      }
    }
  }
}

You will see the result similar to below:

{
  "data": {
    "crabs": {
      "totalCount": 28320,
      "nodes": [
        {
          "id": "468847",
          "addressId": "0x57a3f535a6edce9fba36af2294462e004fb05050",
          "daddyId": "459898",
          "mommyId": "459907",
          "dna": "618396472672434515354154125260029701206476861469507044587729342789599518302",
          "birthday": "1664233214",
          "breedingCount": 3,
          "mintedBlock": "30160740",
          "mintedTimestamp": "1684378541",
          "currentOwnerId": "0x57a3f535a6edce9fba36af2294462e004fb05050",
          "minterAddressId": "0x45f54251dc012524791d14e5089dc67c5199004d",
          "metadataUrl": null,
          "transfers": {
            "totalCount": 1,
            "nodes": [
              {
                "transactionHash": "0x0698664b653fa518f8fedb5f620ecd76410ada525197419d65450d7110a31d6e",
                "block": "30160740",
                "crabId": "468847"
              }
            ]
          }
        },
        {
          "id": "468812",
          "addressId": "0xfcc9e06736a4700842de9b74a350b6dc8eb3fb9e",
          "daddyId": null,
          "mommyId": null,
          "dna": "455846542712823157032490755191673239445204276297111363276289902986384010862",
          "birthday": "1664232661",
          "breedingCount": 0,
          "mintedBlock": "30160740",
          "mintedTimestamp": "1684378541",
          "currentOwnerId": "0xfcc9e06736a4700842de9b74a350b6dc8eb3fb9e",
          "minterAddressId": "0x45f54251dc012524791d14e5089dc67c5199004d",
          "metadataUrl": null,
          "transfers": {
            "totalCount": 1,
            "nodes": [
              {
                "transactionHash": "0x0698664b653fa518f8fedb5f620ecd76410ada525197419d65450d7110a31d6e",
                "block": "30160740",
                "crabId": "468812"
              }
            ]
          }
        },
        {
          "id": "468820",
          "addressId": "0xe7ee8b644d8938a8a7be599f99c21f618cba3e8f",
          "daddyId": "459689",
          "mommyId": "459687",
          "dna": "491183484008390843624156705206532834116397578442780201281914094049666930198",
          "birthday": "1664232789",
          "breedingCount": 2,
          "mintedBlock": "30160740",
          "mintedTimestamp": "1684378541",
          "currentOwnerId": "0xe7ee8b644d8938a8a7be599f99c21f618cba3e8f",
          "minterAddressId": "0x45f54251dc012524791d14e5089dc67c5199004d",
          "metadataUrl": null,
          "transfers": {
            "totalCount": 1,
            "nodes": [
              {
                "transactionHash": "0x0698664b653fa518f8fedb5f620ecd76410ada525197419d65450d7110a31d6e",
                "block": "30160740",
                "crabId": "468820"
              }
            ]
          }
        },
        {
          "id": "468816",
          "addressId": "0x9a08fa6d83812318caa29772cdffd55a48343c39",
          "daddyId": "459941",
          "mommyId": "451583",
          "dna": "514152495850509839908739572716192611354096695614913321283260330842175907109",
          "birthday": "1664232725",
          "breedingCount": 2,
          "mintedBlock": "30160740",
          "mintedTimestamp": "1684378541",
          "currentOwnerId": "0x9a08fa6d83812318caa29772cdffd55a48343c39",
          "minterAddressId": "0x45f54251dc012524791d14e5089dc67c5199004d",
          "metadataUrl": null,
          "transfers": {
            "totalCount": 1,
            "nodes": [
              {
                "transactionHash": "0x0698664b653fa518f8fedb5f620ecd76410ada525197419d65450d7110a31d6e",
                "block": "30160740",
                "crabId": "468816"
              }
            ]
          }
        },
        {
          "id": "468825",
          "addressId": "0xfcc9e06736a4700842de9b74a350b6dc8eb3fb9e",
          "daddyId": null,
          "mommyId": "456995",
          "dna": "535354660627850451863739142725108770444746476243334240700692594647251497779",
          "birthday": "1664232942",
          "breedingCount": 0,
          "mintedBlock": "30160740",
          "mintedTimestamp": "1684378541",
          "currentOwnerId": "0xfcc9e06736a4700842de9b74a350b6dc8eb3fb9e",
          "minterAddressId": "0x45f54251dc012524791d14e5089dc67c5199004d",
          "metadataUrl": null,
          "transfers": {
            "totalCount": 1,
            "nodes": [
              {
                "transactionHash": "0x0698664b653fa518f8fedb5f620ecd76410ada525197419d65450d7110a31d6e",
                "block": "30160740",
                "crabId": "468825"
              }
            ]
          }
        }
      ]
    }
  }
}

Note

The final code of this project can be found here.

What's next?

Congratulations! You have now a locally running SubQuery project that accepts GraphQL API requests for transferring data.

Tip

Find out how to build a performant SubQuery project and avoid common mistakes in Project Optimisation.

Click here to learn what should be your next step in your SubQuery journey.