SubQuery - Starter Package

The Starter Package is an example that you can use as a starting point for developing your SubQuery project. A SubQuery package defines which data The SubQuery will index from the blockchain, and how it will store it.

This SubQuery Ethereum starter project indexes transfers and approvals for the Ethereum Wrapped Ether smart contract.

Note: If the starter project shows a "failed to fetch blocks", it is highly likely that the endpoint has an issue, often with rate limiting. Please visit https://onfinality.io/ and sign up for a free API key.

Preparation

Environment

• Typescript are required to compile project and define types.

• Both SubQuery CLI and generated Project have dependencies and require Node.

Install the SubQuery CLI

Install SubQuery CLI globally on your terminal by using NPM:

npm install -g @subql/cli

Run help to see available commands and usage provide by CLI

subql help

Initialize the starter package

Inside the directory in which you want to create the SubQuery project, simply replace project-name with your project name and run the command:

subql init --starter project-name

Then you should see a folder with your project name has been created inside the directory, you can use this as the start point of your project. And the files should be identical as in the Directory Structure.

Last, under the project directory, run following command to install all the dependency.

yarn install

Configure your project

In the starter package, we have provided a simple example of project configuration. You will be mainly working on the following files:

• The Manifest in project.yaml
• The GraphQL Schema in schema.graphql
• The Mapping functions in src/mappings/ directory

For more information on how to write the SubQuery, check out our doc section on Define the SubQuery

Code generation

In order to index your SubQuery project, it is mandatory to build your project first. Run this command under the project directory.

yarn codegen

Build the project

In order to deploy your SubQuery project to our hosted service, it is mandatory to pack your configuration before upload. Run pack command from root directory of your project will automatically generate a your-project-name.tgz file.

yarn build

Indexing and Query

Run required systems in docker

Under the project directory run following command:

docker-compose pull && docker-compose up

Query the project

Open your browser and head to http://localhost:3000.

Finally, you should see a GraphQL playground is showing in the explorer and the schemas that ready to query.

For the subql-starter project, you can try to query with the following code to get a taste of how it works.

{
  query {
    transactions(first:2 orderBy:BLOCK_HEIGHT_ASC){
      totalCount
        nodes{
          id
          txHash
          blockHeight
          to
          from
          value
          contractAddress
        }
    }
  }
}