The Graph

Like Ethereum and Filecoin‘s IPFS, the Graph is an indexing protocol for querying networks. Users can build and publish open APIs, called subgraphs, making data easily accessible.

Projects with complex smart contracts like Uniswap and NFTs initiatives like Bored Ape Yacht Club store data (more in Ape Coin) on the Ethereum blockchain, making it difficult to read anything besides basic data directly from the blockchain.

The Graph can perform basic contract read operations, such as getting the owner of a particular Ape, acquiring the Ape’s content URI based on their ID, or the general offer, because these read operations are programmed directly into the smart contract. Still, more advanced real-world queries and procedures like aggregation, search, relationships, and non-trivial filtering are impossible. For example, we want to query the apes owned by a certain address and filter by one of its characteristics. In that case, we won’t get that information by directly interacting with the contract.

To get this data, you must process every event broadcasted, read the IPFS metadata using the Token ID and IPFS hash, and then aggregate it. Even these relatively simple questions would take hours or even days for a decentralized application (dapp) to run in a browser to get an answer.

You can also build your server, process the transactions there, save them to a database, and build an API endpoint to query the data. However, this option is resource-intensive, requires maintenance, presents a single point of failure, and violates important security properties necessary for decentralization.

Blockchain properties like finality, chain reorganizations, or uncalled blocks complicate this process further and make it more than just time-consuming but conceptually hard to retrieve correct query results from blockchain data.

Graph solves this with a decentralized protocol that indexes and enables the productive and efficient querying of blockchain data. These APIs (indexed “subgraphs”) can then be queried with a standard GraphQL API. Today, a hosted service and a decentralized protocol have the same capabilities, and the open-source implementation of Graph Node backs both.

Graph learns what and how to index Ethereum data based on subgraph descriptions known as the subgraph manifest. The subgraph description defines the smart contracts of interest for a given subgraph, the events in those contracts to pay attention to, and how to map event data to data that The Graph will store in its database. After writing a subgraph manifest, use the Graph CLI to save the definition to IPFS and tell the indexer to start indexing the data for that subgraph.