Mantle Quick Start
Mantle Quick Start
Goals
The goal of this quick start guide is to index all transfers and approval events from the Mantle Native token on Mantle Network.
Note
Before we begin, make sure that you have initialised your project using the provided steps in the Start Here section. Please initialise an a Mantle project.
In every SubQuery project, there are 3 key files to update. Let's begin updating them one by one.
Note
The final code of this project can be found here.
We use Ethereum packages, runtimes, and handlers (e.g. @subql/node-ethereum
, ethereum/Runtime
, and ethereum/*Hander
) for Mantle. Since Mantle is an EVM-compatible layer-1, we can use the core Ethereum framework to index it.
1. Your Project Manifest File
The Project Manifest (project.ts
) file works as an entry point to your Mantle project. It defines most of the details on how SubQuery will index and transform the chain data. For Mantle, there are three types of mapping handlers (and you can have more than one in each project):
- BlockHanders: On each and every block, run a mapping function
- TransactionHandlers: On each and every transaction that matches optional filter criteria, run a mapping function
- LogHanders: On each and every log that matches optional filter criteria, run a mapping function
Note that the manifest file has already been set up correctly and doesn’t require significant changes, but you need to import the correct contract definitions and update the datasource handlers.
As we are indexing all transfers and approvals from the Mantle Native token on Mantle Network, the first step is to import the contract abi definition which can be obtained from from any standard ERC-20 contract. Copy the entire contract ABI and save it as a file called erc20.abi.json
in the /abis
directory.
Update the datasources
section as follows:
{
dataSources: [
{
kind: EthereumDatasourceKind.Runtime,
startBlock: 1,
// This is the contract address for the Mantle native token https://explorer.mantle.xyz/token/0xDeadDeAddeAddEAddeadDEaDDEAdDeaDDeAD0000/token-transfers
options: {
// Must be a key of assets
abi: "erc20",
// this is the contract address for wrapped ether https://lineascan.build/token/0xe5d7c2a44ffddf6b295a15c148167daaaf5cf34f
address: "0xDeadDeAddeAddEAddeadDEaDDEAdDeaDDeAD0000",
},
assets: new Map([["erc20", { file: "./abis/erc20.abi.json" }]]),
mapping: {
file: "./dist/index.js",
handlers: [
{
kind: EthereumHandlerKind.Call,
handler: "handleTransaction",
filter: {
/**
* The function can either be the function fragment or signature
* function: '0x095ea7b3'
* function: '0x7ff36ab500000000000000000000000000000000000000000000000000000000'
*/
function: "approve(address spender, uint256 rawAmount)",
},
},
{
kind: EthereumHandlerKind.Event,
handler: "handleLog",
filter: {
/**
* Follows standard log filters https://docs.ethers.io/v5/concepts/events/
* address: "0x60781C2586D68229fde47564546784ab3fACA982"
*/
topics: [
"Transfer(address indexed from, address indexed to, uint256 amount)",
],
},
},
],
},
},
],
}
The above code indicates that you will be running a handleTransaction
mapping function whenever there is a approve
method being called on any transaction from the Mantle Native token.
The code also indicates that you will be running a handleLog
mapping function whenever there is a Transfer
event being emitted from the Mantle Native token.
Check out our Manifest File documentation to get more information about the Project Manifest (project.ts
) file.
2. Update Your GraphQL Schema File
The schema.graphql
file determines the shape of your data from SubQuery due to the mechanism of the GraphQL query language. Hence, updating the GraphQL Schema file is the perfect place to start. It allows you to define your end goal right at the start.
Remove all existing entities and update the schema.graphql
file as follows. Here you can see we are indexing block information such as the id, blockHeight, transfer receiver and transfer sender along with an approvals and all of the attributes related to them (such as owner and spender etc.).
type Transfer @entity {
id: ID! # Transaction hash
blockHeight: BigInt
to: String!
from: String!
value: BigInt!
contractAddress: String!
}
type Approval @entity {
id: ID! # Transaction hash
blockHeight: BigInt
owner: String!
spender: String!
value: BigInt!
contractAddress: String!
}
SubQuery makes it easy and type-safe to work with your GraphQL entities, as well as smart contracts, events, transactions, and logs. SubQuery CLI will generate types from your project's GraphQL schema and any contract ABIs included in the data sources.
yarn codegen
npm run-script codegen
This will create a new directory (or update the existing one) src/types
which contains generated entity classes for each type you have defined previously in schema.graphql
. These classes provide type-safe entity loading, and read and write access to entity fields - see more about this process in the GraphQL Schema. All entities can be imported from the following directory:
import { Approval, Transfer } from "../types";
If you're creating a new EVM-based project, this command will also generate ABI types and save them into src/types
using the npx typechain --target=ethers-v5
command, allowing you to bind these contracts to specific addresses in the mappings and call read-only contract methods against the block being processed. It will also generate a class for every contract event to provide easy access to event parameters, as well as the block and transaction the event originated from. All of these types are written to src/types/abi-interfaces
and src/types/contracts
directories. In this example SubQuery project, you would import these types like so.
import {
ApproveTransaction,
TransferLog,
} from "../types/abi-interfaces/Erc20Abi";
Important
When you make any changes to the schema file, please ensure that you regenerate your types directory using the SubQuery CLI prompt yarn codegen
or npm run-script codegen
.
Check out the GraphQL Schema documentation to get in-depth information on schema.graphql
file.
3. Add a Mapping Function
Mapping functions define how chain data is transformed into the optimised GraphQL entities that we previously defined in the schema.graphql
file.
Navigate to the default mapping function in the src/mappings
directory. You will be able to see two exported functions handleLog
and handleTransaction
:
export async function handleLog(log: TransferLog): Promise<void> {
logger.info(`New transfer transaction log at block ${log.blockNumber}`);
assert(log.args, "No log.args");
const transaction = Transfer.create({
id: log.transactionHash,
blockHeight: BigInt(log.blockNumber),
to: log.args.to,
from: log.args.from,
value: log.args.value.toBigInt(),
contractAddress: log.address,
});
await transaction.save();
}
export async function handleTransaction(tx: ApproveTransaction): Promise<void> {
logger.info(`New Approval transaction at block ${tx.blockNumber}`);
assert(tx.args, "No tx.args");
const approval = Approval.create({
id: tx.hash,
owner: tx.from,
spender: await tx.args[0],
value: BigInt(await tx.args[1].toString()),
contractAddress: tx.to,
});
await approval.save();
}
The handleLog
function receives a log
parameter of type TransferLog
which includes log data in the payload. We extract this data and then save this to the store using the .save()
function (Note that SubQuery will automatically save this to the database).
The handleTransaction
function receives a tx
parameter of type ApproveTransaction
which includes transaction data in the payload. We extract this data and then save this to the store using the .save()
function (Note that SubQuery will automatically save this to the database).
Check out our Mappings documentation to get more information on mapping functions.
4. Build Your Project
Next, build your work to run your new SubQuery project. Run the build command from the project's root directory as given here:
yarn build
npm run-script build
Important
Whenever you make changes to your mapping functions, you must rebuild your project.
Now, you are ready to run your first SubQuery project. Let’s check out the process of running your project in detail.
5. Run Your Project Locally with Docker
Whenever you create a new SubQuery Project, first, you must run it locally on your computer and test it and using Docker is the easiest and quickest way to do this.
The docker-compose.yml
file defines all the configurations that control how a SubQuery node runs. For a new project, which you have just initialised, you won't need to change anything.
However, visit the Running SubQuery Locally to get more information on the file and the settings.
Run the following command under the project directory:
yarn start:docker
npm run-script start:docker
Note
It may take a few minutes to download the required images and start the various nodes and Postgres databases.
6. Query your Project
Next, let's query our project. Follow these three simple steps to query your SubQuery project:
Open your browser and head to
http://localhost:3000
.You will see a GraphQL playground in the browser and the schemas which are ready to query.
Find the Docs tab on the right side of the playground which should open a documentation drawer. This documentation is automatically generated and it helps you find what entities and methods you can query.
Try the following query to understand how it works for your new SubQuery starter project. Don’t forget to learn more about the GraphQL Query language.
# Write your query or mutation here
{
query {
transfers(first: 5, orderBy: VALUE_DESC) {
totalCount
nodes {
id
blockHeight
from
to
value
contractAddress
}
}
}
approvals(first: 5, orderBy: BLOCK_HEIGHT_DESC) {
nodes {
id
blockHeight
owner
spender
value
contractAddress
}
}
}
You will see the result similar to below:
{
"data": {
"query": {
"transfers": {
"totalCount": 143,
"nodes": [
{
"id": "0x726c97aef8f42f1c7eedd9762e105c426d0b216be73d8360811df475f624c3e2",
"blockHeight": "10926",
"from": "0xAED47A51AeFa6f95A388aDA3c459d94FF46fC4BB",
"to": "0x7739E567B9626ca241bdC5528343F92F7e59Af37",
"value": "179900000000000000000",
"contractAddress": "0x5300000000000000000000000000000000000004"
},
{
"id": "0x71305b1bfd3b5aa1b0236c1ae7ce137aff7757cf1a4a38ace9a22235e5d0b4bf",
"blockHeight": "11064",
"from": "0xAED47A51AeFa6f95A388aDA3c459d94FF46fC4BB",
"to": "0x7739E567B9626ca241bdC5528343F92F7e59Af37",
"value": "122000000000000000000",
"contractAddress": "0x5300000000000000000000000000000000000004"
},
{
"id": "0xe5305b8b35c72b4752d152fa7ade7e065759483432965cc90a3703fda3d8a8a5",
"blockHeight": "11083",
"from": "0xAED47A51AeFa6f95A388aDA3c459d94FF46fC4BB",
"to": "0x7739E567B9626ca241bdC5528343F92F7e59Af37",
"value": "102000000000000000000",
"contractAddress": "0x5300000000000000000000000000000000000004"
},
{
"id": "0x2d00a4d8fc20f26694ecbdf0c5da285a78212169978b114b06981039d843d36a",
"blockHeight": "11246",
"from": "0xAED47A51AeFa6f95A388aDA3c459d94FF46fC4BB",
"to": "0x7739E567B9626ca241bdC5528343F92F7e59Af37",
"value": "100000000000000000000",
"contractAddress": "0x5300000000000000000000000000000000000004"
},
{
"id": "0xbb7ecb71c3e1cf6727b3761ca21a7199a0ee93ad4862e53058ad3bdd6cc7cce9",
"blockHeight": "11036",
"from": "0xAED47A51AeFa6f95A388aDA3c459d94FF46fC4BB",
"to": "0x7739E567B9626ca241bdC5528343F92F7e59Af37",
"value": "100000000000000000000",
"contractAddress": "0x5300000000000000000000000000000000000004"
}
]
}
},
"approvals": {
"nodes": [
{
"id": "0xfb1590aa76ef5ea8a12c4e3a1c988fd5fabf9dd65f77a5ec1ff7f27868bf3086",
"blockHeight": null,
"owner": "0x7C563F9423C93Fed57c6aC2cC562b0DE0956abB0",
"spender": "0xbbAd0e891922A8A4a7e9c39d4cc0559117016fec",
"value": "115792089237316195423570985008687907853269984665640564039457584007913129639935",
"contractAddress": "0x5300000000000000000000000000000000000004"
},
{
"id": "0x997f7c27dd9812e84f3dd8859fe8ac7dfc957a9778efe54cf2d8ff7c655f7bef",
"blockHeight": null,
"owner": "0x7C563F9423C93Fed57c6aC2cC562b0DE0956abB0",
"spender": "0xbbAd0e891922A8A4a7e9c39d4cc0559117016fec",
"value": "1000000000000000000000000",
"contractAddress": "0x5300000000000000000000000000000000000004"
},
{
"id": "0xfdf276d97f2fe1148ecce71d261aed8fd38d59283389d51b9b76d413acc5a3ed",
"blockHeight": null,
"owner": "0x7C563F9423C93Fed57c6aC2cC562b0DE0956abB0",
"spender": "0xbbAd0e891922A8A4a7e9c39d4cc0559117016fec",
"value": "115792089237316195423570985008687907853269984665640564039457584007913129639935",
"contractAddress": "0x5300000000000000000000000000000000000004"
},
{
"id": "0xcccc7e065b119588e7278169b8e6e017e9fa0d0209af28047bbb39ef7e0db9ee",
"blockHeight": null,
"owner": "0x2cFe53AaD05F1156FDcED046690749cCb774CfDD",
"spender": "0xbbAd0e891922A8A4a7e9c39d4cc0559117016fec",
"value": "1000000000000000000",
"contractAddress": "0x5300000000000000000000000000000000000004"
},
{
"id": "0xf3d60b7016e35e3a865ceb7df16e5e440a80bdae5f9fbe73996245e6c7d65482",
"blockHeight": null,
"owner": "0xCa266224613396A0e8D4C2497DBc4F33dD6CDEFf",
"spender": "0x481B20A927206aF7A754dB8b904B052e2781ea27",
"value": "19600000000000000",
"contractAddress": "0x5300000000000000000000000000000000000004"
}
]
}
}
}
Note
The final code of this project can be found here.
What's next?
Congratulations! You have now a locally running SubQuery project that accepts GraphQL API requests for transferring data.
Tip
Find out how to build a performant SubQuery project and avoid common mistakes in Project Optimisation.
Click here to learn what should be your next step in your SubQuery journey.