Building Subgraphs on Arweave

Arweave support in Graph Node and on the Hosted Service is in beta: please reach us on Discord with any questions about building Arweave subgraphs!

In this guide, you will learn how to build and deploy Subgraphs to index the Arweave blockchain.

What is Arweave?

The Arweave protocol allows developers to store data permanently and that is the main difference between Arweave and IPFS, where IPFS lacks the feature; permanence, and files stored on Arweave can't be changed or deleted.

Arweave already has built numerous libraries for integrating the protocol in a number of different programming languages. For more information you can check:

• Arwiki

• Arweave Resources

What are Arweave Subgraphs?

The Graph allows you to build custom open APIs called "Subgraphs". Subgraphs are used to tell indexers (server operators) which data to index on a blockchain and save on their servers in order for you to be able to query it at any time using GraphQL.

Graph Node is now able to index data on Arweave protocol. The current integration is only indexing Arweave as a blockchain (blocks and transactions), it is not indexing the stored files yet.

Building an Arweave Subgraph

To be able to build and deploy Arweave Subgraphs, you need two packages:

1. @graphprotocol/graph-cli above version 0.30.2 - This is a command-line tool for building and deploying subgraphs. Click here to download using npm.

2. @graphprotocol/graph-ts above version 0.27.0 - This is library of subgraph-specific types. Click here to download using npm.

Subgraph's components

There are three components of a subgraph:

1. Manifest - subgraph.yaml

Defines the data sources of interest, and how they should be processed. Arweave is a new kind of data source.

2. Schema - schema.graphql

Here you define which data you want to be able to query after indexing your Subgraph using GraphQL. This is actually similar to a model for an API, where the model defines the structure of a request body.

The requirements for Arweave subgraphs are covered by the existing documentation.

3. AssemblyScript Mappings - mapping.ts

This is the logic that determines how data should be retrieved and stored when someone interacts with the data sources you are listening to. The data gets translated and is stored based off the schema you have listed.

During subgraph development there are two key commands:

$ graph codegen # generates types from the schema file identified in the manifest$ graph build # generates Web Assembly from the AssemblyScript files, and prepares all the subgraph files in a /build folder

Subgraph Manifest Definition

The subgraph manifest subgraph.yaml identifies the data sources for the subgraph, the triggers of interest, and the functions that should be run in response to those triggers. See below for an example subgraph manifest for an Arweave subgraph:

specVersion: 0.0.5description: Arweave Blocks Indexingschema:  file: ./schema.graphql # link to the schema filedataSources:  - kind: arweave    name: arweave-blocks    network: arweave-mainnet # The Graph only supports Arweave Mainnet    source:      owner: "ID-OF-AN-OWNER" # The public key of an Arweave wallet      startBlock: 0 # set this to 0 to start indexing from chain genesis    mapping:      apiVersion: 0.0.5      language: wasm/assemblyscript      file: ./src/blocks.ts # link to the file with the Assemblyscript mappings      entities:        - Block        - Transaction      blockHandlers:        - handler: handleBlock # the function name in the mapping file      transactionHandlers:        - handler: handleTx # the function name in the mapping file

• Arweave subgraphs introduce a new kind of data source (arweave)

• The network should correspond to a network on the hosting Graph Node. On the Hosted Service, Arweave's mainnet is arweave-mainnet

• Arweave data sources introduce an optional source.owner field, which is the public key of an Arweave wallet

Arweave data sources support two types of handlers:

• blockHandlers - Run on every new Arweave block. No source.owner is required.

• transactionHandlers - Run on every transaction where the data source's source.owner is the owner. Note that only exact matches are processed. Currently an owner is required for transactionHandlers.

The source.owner is the owner's Public Key, rather than the owner's address.

Transactions are the building blocks of the Arweave permaweb and they are objects created by end-users.

Note: Bundlr transactions are not supported yet.

Schema Definition

Schema definition describes the structure of the resulting subgraph database and the relationships between entities. This is agnostic of the original data source. There are more details on the subgraph schema definition here.

AssemblyScript Mappings

The handlers for processing events are written in AssemblyScript.

Arweave indexing introduces Arweave-specific data types to the AssemblyScript API.

class Block {     timestamp: u64     lastRetarget: u64     height: u64     indepHash: Bytes     nonce: Bytes     previousBlock: Bytes     diff: Bytes     hash: Bytes     txRoot: Bytes     txs: Bytes[]     walletList: Bytes     rewardAddr: Bytes     tags: Tag[]     rewardPool: Bytes     weaveSize: Bytes     blockSize: Bytes     cumulativeDiff: Bytes     hashListMerkle: Bytes     poa: ProofOfAccess}
class Transaction {     format: u32     id: Bytes     lastTx: Bytes     owner: Bytes     tags: Tag[]     target: Bytes     quantity: Bytes     data: Bytes     dataSize: Bytes     dataRoot: Bytes     signature: Bytes     reward: Bytes}

Block handlers receive a Block, while transactions receive a Transaction.

Writing the mappings of an Arweave Subgraph is very similar to writing the mappings of an Ethereum Subgraph. For more information, click here.

Deploying an Arweave Subgraph on the Hosted Service

Once your subgraph has been created on the Hosed Service dashboard, you can deploy by using the graph deploy CLI command.

graph deploy --node https://api.thegraph.com/deploy/ --ipfs https://api.thegraph.com/ipfs/ --access-token <your-access-token>

Querying an Arweave Subgraph

The GraphQL endpoint for Arweave subgraphs is determined by the schema definition, with the existing API interface. Please visit the GraphQL API documentation for more information.

Example Subgraphs

Here is an example subgraph for reference:

• Example subgraph for Arweave

FAQ

Can a subgraph index Arweave and other chains?

No, a subgraph can only support data sources from one chain/network.

Can I index the stored files on Arweave?

Currently, The Graph is only indexing Arweave as a blockchain (its blocks and transactions).

Can I identify Bundlr bundles in my subgraph?

This is not currently supported.

How can I filter transactions to a specific account?

The source.owner is the user's public key, rather than the account address. We are working on adding account filtering support.

What is the current encryption format?

Data is generally passed into the mappings as Bytes, which if stored directly is returned in the subgraph in a hex format (ex. block and transaction hashes). You may want to convert to a base64 or base64 URL-safe format in your mappings, in order to match what is displayed in block explorers like Arweave Explorer.

The following bytesToBase64(bytes: Uint8Array, urlSafe: boolean): string helper function can be used, and will be added to graph-ts:

const base64Alphabet = [	"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",	"N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z",	"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m",	"n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z",	"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "+", "/"];
const base64UrlAlphabet = [	"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",	"N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z",	"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m",	"n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z",	"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "-", "_"];
function bytesToBase64(bytes: Uint8Array, urlSafe: boolean): string {	let alphabet = urlSafe? base64UrlAlphabet : base64Alphabet;
	let result = '', i: i32, l = bytes.length;	for (i = 2; i < l; i += 3) {		result += alphabet[bytes[i - 2] >> 2];		result += alphabet[((bytes[i - 2] & 0x03) << 4) | (bytes[i - 1] >> 4)];		result += alphabet[((bytes[i - 1] & 0x0F) << 2) | (bytes[i] >> 6)];		result += alphabet[bytes[i] & 0x3F];	}	if (i === l + 1) { // 1 octet yet to write		result += alphabet[bytes[i - 2] >> 2];		result += alphabet[(bytes[i - 2] & 0x03) << 4];		if (!urlSafe) {			result += "==";		}	}	if (!urlSafe && i === l) { // 2 octets yet to write		result += alphabet[bytes[i - 2] >> 2];		result += alphabet[((bytes[i - 2] & 0x03) << 4) | (bytes[i - 1] >> 4)];		result += alphabet[(bytes[i - 1] & 0x0F) << 2];		if (!urlSafe) {			result += "=";		}	}	return result;}