The Graph

The Graph is a decentralized protocol for requesting data from a blockchain and indexing it. This text is from community cryptodefi​x. The protocol allows users to query data that is difficult to query directly. The Graph helps link a project to a blockchain and helps index its data. Indexes (“subgraphs”) can be queried using the GraphQL API.

The Graph works in the Ethereum blockchain and shows how and what needs to be indexed in a project, this is called a subgraph manifest. The description of the subgraph defines smart contracts to show the right information about the project, the events in it, and to write data to the database. After writing the subgraph manifest, the user needs to use the Graph CLI to save the definition to IPFS and pass a request to the project to start indexing data for that subgraph.

How to get started in The Graph:

• A decentralized application adds data to Ethereum using smart contracts.
• The smart contract processes the requests.
• Graph Node scans the Ethereum blockchain for new blocks or data.
• Graph Node looks for events in Ethereum blocks for a subgraph and runs mapping handlers. Mapping allows you to create and update data in the Graph Node.
• The decentralized application queries the Graph Node for data indexed from the blockchain, using the node's GraphQL endpoint. The Graph Node in turn translates the GraphQL queries into queries for its underlying data store in order to fetch this data, making use of the store's indexing capabilities. The decentralized application displays this data in a rich UI for end-users, which they use to issue new transactions on Ethereum. The cycle repeats.

The Graph characteristics:

• Facilitate work with the blockchain through indexing.
• Storing project data inside The Graph.
• Creating multifunctional Dapps.
• Support for different types of blockchain.