Unlocking the Power of Blockchain Data with The Graph
The Graph is a revolutionary indexing protocol that enables easier access to blockchain data. By leveraging a GraphQL API, it provides a more efficient and streamlined way to query on-chain information compared to traditional methods. In this article, we’ll explore how to harness the power of The Graph and subgraphs for Web3 data querying.
Key Players in The Graph Ecosystem
- Indexers: Operate network nodes, indexing data and serving queries. They stake Graph Tokens (GRT) to provide indexing and query processing services.
- Curators: Signal high-quality subgraphs, organizing data from the subgraphs and indicating which ones should be indexed by the Graph Network.
- Delegators: Secure the network by staking GRT to one or more Indexers, earning portions of the Indexer’s query fees and rewards.
The Graph Foundation and Services
The Graph is developed and maintained by The Graph Foundation, which distributes grants to community members working on protocol infrastructure, tooling, dApps, subgraphs, and community building. There are three ways to interact with The Graph:
- Graph Explorer: Explore different subgraphs and interact with the Graph protocol.
- Subgraph Studio: Create, manage, and publish subgraphs and API keys using Ethereum Mainnet.
- Hosted Service: Create, manage, and publish subgraphs and API keys using other networks aside from Ethereum.
Creating a Project on Hosted Service
To get started with The Graph, create an account on the Hosted Service and set up a new project. This involves creating a subgraph, defining entities, generating types, and writing mappings.
Defining Entities and Subgraph
In the schema.graphql file, define two types: Token and User. The Token has attributes such as name, content URI, and IPFS file path, while the User has attributes like ID, tokens owned, and tokens created.
Generating Types and Writing Mappings
Generate AssemblyScript types for the ABI and subgraph schema. Write mappings to transform smart contract events into entities in the store.
Deploying the Subgraph
Build and deploy the project, including the subgraph and API endpoint. Wait for the subgraph to sync with the current state of the blockchain before running queries.
Querying the Subgraph
Use the API endpoint or HTTP endpoint to send GraphQL queries directly with cURL. Run queries to retrieve data, such as the first two tokens ordered by ID in descending order or the first user and their associated content.
Conclusion
The Graph provides a powerful tool for querying blockchain data. By creating a subgraph and defining entities, developers can unlock the full potential of Web3 applications. With its standardized query language, The Graph enables developers to iterate and test their applications with greater efficiency.