Dymension Quick Start

SubQuery TeamAbout 1 min

Dymension Quick Start

Dymension works like a big web system. Users use RollApps (front-end), the Dymension Hub (back-end) manages everything, and data networks (database) store information. RollApps are like interactive apps in Dymension.

The goal of this quick start guide is to index all transfer events and messages on the Dymension network.

Info

This network is based on the Cosmos SDK, which means you can index chain data via the standard Cosmos RPC interface.

Before we begin, make sure that you have initialised your project using the provided steps in the Start Here section. You must complete the suggested 4 steps for Cosmos users.

Tips

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 Cosmos chains, there are four 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, run a mapping function
MessageHandlers: On each and every message that matches optional filter criteria, run a mapping function
EventHanders: On each and every event that matches optional filter criteria, run a mapping function

Note that the manifest file has already been set up correctly and doesn’t require significant changes, but you need to change the datasource handlers. This section lists the triggers that the manifest file looks for on the blockchain to start indexing.

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 Cosmos chains, there are four 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, run a mapping function
MessageHandlers: On each and every message that matches optional filter criteria, run a mapping function
EventHanders: On each and every event that matches optional filter criteria, run a mapping function

project.ts

dataSources: [
  {
    kind: CosmosDatasourceKind.Runtime,
    startBlock: 1326903,
    mapping: {
      file: "./dist/index.js",
      handlers: [
        {
          handler: "handleEvent",
          kind: CosmosHandlerKind.Event,
          filter: {
            type: "transfer",
            messageFilter: {
              type: "/cosmos.bank.v1beta1.MsgSend",
            },
          },
        },
      ],
    },
  },
];

Here we are in search of a single type of – namely, transfer representing the transfers.

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.

Update Your GraphQL Schema File

type Transfer @entity {
  id: ID!
  blockHeight: BigInt
  txHash: String
  fromAddress: String
  toAddress: String
  amount: String
}

The single enity is the Transfer.

SubQuery simplifies and ensures type-safety when working with GraphQL entities, actions, and transactions.

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.

If you've expressed a preference to employ the Cosmos message based on the provided proto files, this command will also generate types for your listed protobufs and save them into src/types directory, providing you with more typesafety. For example, you can find Osmosis' protobuf definitions in the official documentation. Read about how this is done in Cosmos Codegen from CosmWasm Protobufs and Cosmos Manifest File Configuration.

Now that you have made essential changes to the GraphQL Schema file, let’s go ahead with the next 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.

Note

Check out our Mappings documentation to get more information on mapping functions.

Navigate to the default mapping function in the src/mappings directory. Setting up mappings for this the Cosmos chains is straightforward. In this instance, the mappings are stored within the src/mappings directory, with the sole mapping file being mappingHandlers.ts. Now, let's take a closer look at it:

mappingHandlers.ts

import { Transfer } from "../types";
import { CosmosEvent } from "@subql/types-cosmos";

export async function handleEvent(event: CosmosEvent): Promise<void> {
  const eventRecord = Transfer.create({
    id: `${event.tx.hash}-${event.msg.idx}-${event.idx}`,
    blockHeight: BigInt(event.block.block.header.height),
    txHash: event.tx.hash,
    toAddress: "",
    amount: "",
    fromAddress: "",
  });
  for (const attr of event.event.attributes) {
    switch (attr.key) {
      case "recipient":
        eventRecord.toAddress = attr.value;
        break;
      case "amount":
        eventRecord.amount = attr.value;
        break;
      case "sender":
        eventRecord.fromAddress = attr.value;
        break;
      default:
        break;
    }
  }
  await eventRecord.save();
}

In the Dymension SubQuery project, we have two a single function, namely handleEvent. The handleEvent function is also triggered when a /cosmos.bank.v1beta1.MsgSend type message is detected for a transfer. It receives an event of type CosmosEvent, and then it also extracts blockHeight, transaction hash, from, to and amount from the event object.

Check out our Mappings documentation and get information on the mapping functions in detail.

Tips

The final code of this project can be found here.

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.

Request

{
  query {
    transfers(first: 5) {
      nodes {
        id
        blockHeight
        txHash
        recipient
        sender
        amount
      }
    }
  }
}

Response

{
  "data": {
    "query": {
      "transfers": {
        "nodes": [
          {
            "id": "56C9A9D33C8C222A25D16AFF1C032561703F765D3DB1DD2B217B07DDB394A24C-0-0",
            "blockHeight": "1651519",
            "txHash": "56C9A9D33C8C222A25D16AFF1C032561703F765D3DB1DD2B217B07DDB394A24C",
            "fromAddress": "dym1g8sf7w4cz5gtupa6y62h3q6a4gjv37pgefnpt5",
            "toAddress": "dym1a4gqlkq2qu8fnncxfv9wdt67zthcfyqwx92g0g",
            "amount": "200000000000000000000udym"
          }
        ]
      }
    }
  }
}

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.