Developer FAQs

Reading time: 8 min

A subgraph is a custom API built on blockchain data. Subgraphs are queried using the GraphQL query language and are deployed to a Graph Node using the Graph CLI. Once deployed and published to The Graph's decentralized network, Indexers process subgraphs and make them available to be queried by subgraph consumers.

It is not possible to delete subgraphs once they are created.

No. Once a subgraph is created, the name cannot be changed. Make sure to think of this carefully before you create your subgraph so it is easily searchable and identifiable by other dapps.

No. Once a subgraph is created, the associated GitHub account cannot be changed. Make sure to think of this carefully before you create your subgraph.

It is highly recommended that you structure your smart contracts to have events associated with data you are interested in querying. Event handlers in the subgraph are triggered by contract events and are by far the fastest way to retrieve useful data.

If the contracts you are working with do not contain events, your subgraph can use call and block handlers to trigger indexing. Although this is not recommended, as performance will be significantly slower.

You will need separate names for multiple networks. While you can't have different subgraphs under the same name, there are convenient ways of having a single codebase for multiple networks. Find more on this in our documentation: Redeploying a Subgraph

Templates allow you to create data sources on the fly, while your subgraph is indexing. It might be the case that your contract will spawn new contracts as people interact with it, and since you know the shape of those contracts (ABI, events, etc) upfront you can define how you want to index them in a template and when they are spawned your subgraph will create a dynamic data source by supplying the contract address.

Check out the "Instantiating a data source template" section on: Data Source Templates.

You can run the following command:

docker pull graphprotocol/graph-node:latest

NOTE: docker / docker-compose will always use whatever graph-node version was pulled the first time you ran it, so it is important to do this to make sure you are up to date with the latest version of graph-node.

Take a look at Access to smart contract state inside the section AssemblyScript API.

Yes. On graph init command itself you can add multiple datasources by entering contracts one after the other. You can also use graph add command to add new datasource.

• graph-node
• graph-tooling
• graph-docs
• graph-client

If only one entity is created during the event and if there's nothing better available, then the transaction hash + log index would be unique. You can obfuscate these by converting that to Bytes and then piping it through crypto.keccak256 but this won't make it more unique.

Within a subgraph, the events are always processed in the order they appear in the blocks, regardless of whether that is across multiple contracts or not.

Yes. You can do this by importing graph-ts as per the example below:

import { dataSource } from '@graphprotocol/graph-ts'

dataSource.network()
dataSource.address()

Yes. Sepolia supports block handlers, call handlers and event handlers. It should be noted that event handlers are far more performant than the other two handlers, and they are supported on every EVM-compatible network.

Not currently, as mappings are written in AssemblyScript. One possible alternative solution to this is to store raw data in entities and perform logic that requires JS libraries on the client.

Yes. dataSources.source.startBlock in the subgraph.yaml file specifies the number of the block that the data source starts indexing from. In most cases, we suggest using the block in which the contract was created: Start blocks

Yes, you should take a look at the optional start block feature to start indexing from the block that the contract was deployed: Start blocks

Yes! Try the following command, substituting "organization/subgraphName" with the organization under it is published and the name of your subgraph:

curl -X POST -d '{ "query": "{indexingStatusForCurrentVersion(subgraphName: \"organization/subgraphName\") { chains { latestBlock { hash number }}}}"}' https://api.thegraph.com/index-node/graphql

You can find the list of the supported networks here.

You have to redeploy the subgraph, but if the subgraph ID (IPFS hash) doesn't change, it won't have to sync from the beginning.

Federation is not supported yet, although we do want to support it in the future. At the moment, something you can do is use schema stitching, either on the client or via a proxy service.

By default, query responses are limited to 100 items per collection. If you want to receive more, you can go up to 1000 items per collection and beyond that, you can paginate with:

someCollection(first: 1000, skip: <number>) { ... }

Currently, the recommended approach for a dapp is to add the key to the frontend and expose it to end users. That said, you can limit that key to a hostname, like yourdapp.io and subgraph. The gateway is currently being run by Edge & Node. Part of the responsibility of a gateway is to monitor for abusive behavior and block traffic from malicious clients.

Head over to the hosted service in order to find subgraphs that you or others deployed to the hosted service. You can find it here.

The Graph will never charge for the hosted service. The Graph is a decentralized protocol, and charging for a centralized service is not aligned with The Graph’s values. The hosted service was always a temporary step to help get to the decentralized network. Developers will have a sufficient amount of time to upgrade to the decentralized network as they are comfortable.

If you’re a subgraph developer, you can deploy a new version of your subgraph to Subgraph Studio using the CLI. It’ll be private at that point, but if you’re happy with it, you can publish to the decentralized Graph Explorer. This will create a new version of your subgraph that Curators can start signaling on.

Event and call handlers are first ordered by transaction index within the block. Event and call handlers within the same transaction are ordered using a convention: event handlers first then call handlers, each type respecting the order they are defined in the manifest. Block handlers are run after event and call handlers, in the order they are defined in the manifest. Also these ordering rules are subject to change.

When new dynamic data source are created, the handlers defined for dynamic data sources will only start processing after all existing data source handlers are processed, and will repeat in the same sequence whenever triggered.