Concordium Quick Start
Concordium Quick Start
The goal of this quick start guide is to give a quick intro to all features of our Concordium indexer. This SubQuery project indexes all transfer transactions, updated transaction events, and block rewards on the Concordium Test Network - it's a great way to quickly learn how SubQuery works on a real world hands-on example.
Important
Before we begin, make sure that you have initialised your project using the provided steps in the Start Here section. Please initialise a Concordium Testnet project
Now, let's move forward and update these configurations.
Previously, in the 1. Create a New Project section, you must have noted 3 key files. Let's begin updating them one by one.
Note
The final code of this project can be found here.
1. Update Your GraphQL Schema File
The schema.graphql file determines the shape of the data that you are using SubQuery to index, hence it's a great place to start. The shape of your data is defined in a GraphQL Schema file with various GraphQL entities.
Remove all existing entities and update the schema.graphql file as follows, here you can see we are indexing a variety of datapoints, including accounts, transfers, credit, debits, and payments.
type Transfer @entity {
id: ID! # A unique ID
block: BigInt!
date: Date!
from: String!
to: String!
value: BigInt!
}
type Updated @entity {
id: ID!
block: BigInt!
txHash: String!
address: String!
instigator: String!
}
type BlockAccrueReward @entity {
id: ID!
block: BigInt!
baker: BigInt!
bakerReward: BigInt!
}
Important
When you make any changes to the schema file, please ensure that you regenerate your types directory.
yarn codegen
npm run-script codegen
You will find the generated models in the /src/types/models directory.
Check out the GraphQL Schema documentation to get in-depth information on schema.graphql file.
Now that you have made essential changes to the GraphQL Schema file, let’s move forward to the next file.
2. Update Your Project Manifest File
The Project Manifest (project.ts) file works as an entry point to your Concordium projects. It defines most of the details on how SubQuery will index and transform the chain data. For Concordium, there are three types of mapping handlers (and you can have more than one in each project):
- Block handler: On each and every block, run a mapping function
- Transaction handlers: On each and every Concordium transaction that matches optional filter criteria, run a mapping function
- TransactionEvent handler: On each and every event related to a specific Concordium transaction that matches optional filter criteria, run a mapping function
- SpecialEvent handler: On each and every Concordium special event 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 we can walk through the different handlers.
{
dataSources: [
{
kind: ConcordiumDatasourceKind.Runtime,
startBlock: 490000,
mapping: {
file: "./dist/index.js",
handlers: [
/**
* Avoid using block handlers where possible as they slow the indexing speed of your project
{
handler: "handleBlock",
kind: ConcordiumHandlerKind.Block,
},
*/
{
handler: "handleTransaction",
kind: ConcordiumHandlerKind.Transaction,
filter: {
type: TransactionSummaryType.AccountTransaction,
values: {
transactionType: "transfer",
},
},
},
{
handler: "handleTransactionEvent",
kind: ConcordiumHandlerKind.TransactionEvent,
filter: {
type: TransactionEventTag.Updated,
},
},
{
handler: "handleSpecialEvent",
kind: ConcordiumHandlerKind.SpecialEvent,
filter: {
type: "blockAccrueReward",
},
},
],
},
},
],
}
The above code indicates that you will be running a handleTransaction mapping function whenever there is a Concordium transaction of type TransactionSummaryType.AccountTransaction wiht the type transfer. Additionally we run the handleTransactionEvent mapping function whenever there is any event on any transaction with the TransactionEventTag.Updated type. Finally, we have a handleSpecialEvent function which runs whenever there is a SpecialEvent of type blockAccrueReward.
Check out our Manifest File documentation to get more information about the Project Manifest (project.ts) file.
Next, let’s proceed ahead with the Mapping Function’s configuration.
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.
Follow these steps to add a mapping function:
Navigate to the default mapping function in the src/mappings directory.
There are four different classes of mapping functions for Concordium; Block handlers, Transaction Handlers, Transaction Event Handlers, and Special Event Handlers.
Update the mappingHandler.ts file as follows (note the additional imports):
import {
AccountTransactionSummary,
BlockSpecialEventBlockAccrueReward,
TransferSummary,
UpdatedEvent,
} from "@concordium/node-sdk";
import { Transfer, Updated, BlockAccrueReward } from "../types";
import {
ConcordiumTransaction,
ConcordiumTransactionEvent,
ConcordiumSpecialEvent,
} from "@subql/types-concordium";
export async function handleTransaction(tx: ConcordiumTransaction) {
logger.info(
`Handling Transaction at block ${tx.block.blockHeight.toString()}`,
);
const record = Transfer.create({
id: `${tx.block.blockHeight}-${tx.hash}`,
block: tx.block.blockHeight,
date: tx.block.blockReceiveTime,
from: (tx as AccountTransactionSummary).sender,
to: (tx as TransferSummary).transfer.to,
value: (tx as TransferSummary).transfer.amount,
});
await record.save();
}
export async function handleTransactionEvent(
txEvent: ConcordiumTransactionEvent,
) {
logger.info(
`Handling Transaction Event at block ${txEvent.block.blockHeight.toString()}`,
);
const record = Updated.create({
id: `${txEvent.transaction.hash}-${txEvent.id}`,
block: txEvent.block.blockHeight,
txHash: txEvent.transaction.hash,
address: `${(txEvent as UpdatedEvent).address.subindex}-${
(txEvent as UpdatedEvent).address.subindex
}`,
instigator: (txEvent as UpdatedEvent).instigator.address.toString(),
});
await record.save();
}
export async function handleSpecialEvent(specialEvent: ConcordiumSpecialEvent) {
logger.info(
`Handling special event at block ${specialEvent.block.blockHeight.toString()}`,
);
const record = BlockAccrueReward.create({
id: `${specialEvent.block.blockHeight}-${specialEvent.id}`,
block: specialEvent.block.blockHeight,
baker: (specialEvent as BlockSpecialEventBlockAccrueReward).baker,
bakerReward: (specialEvent as BlockSpecialEventBlockAccrueReward)
.bakerReward,
});
await record.save();
}
Let’s understand how the above code works.
For the handleTransaction mapping function, the function receives a new ConcordiumTransaction payload to which parse and save into the store as a new Transfer entity.
For the handleTransactionEvent mapping function, the functions receives a new ConcordiumTransactionEvent payload to which it processes. Finally, the handleSpecialEvent mapping function is for ConcordiumSpecialEvents.
Check out our Mappings documentation to get more information on mapping functions.
Note
For more information on mapping functions, please refer to our Mappings documentation.
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.
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 quickiest way to do this.
Run Your Project Locally with Docker
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.
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 queries to understand how it works for your new SubQuery starter project. Don’t forget to learn more about the GraphQL Query language.
{
query {
transfers(first: 5, orderBy: VALUE_DESC) {
nodes {
id
block
date
from
to
value
}
}
blockAccrueRewards(first: 5, orderBy: BLOCK_DESC) {
nodes {
id
block
baker
bakerReward
}
}
}
}
You will see the result similar to below:
{
"data": {
"query": {
"transfers": {
"nodes": [
{
"id": "491566-af551174c69a1cb2714912763a5244a6447a9cb224a60092aeb8f25a9bb3d9a0",
"block": "491566",
"date": "2022-08-09T14:58:11.042",
"from": "3kBx2h5Y2veb4hZgAJWPrr8RyQESKm5TjzF3ti1QQ4VSYLwK1G",
"to": "3SUYtqy9g9JtkhDydnNsLp6H7vDHaqE7TZ3BhagMoEMf5HakYg",
"value": "50000000000"
},
{
"id": "498659-03d998f2606cb4b3a25fe53e6d17eb3f0a619b959257527ac0ec6ae5cbba6eb0",
"block": "498659",
"date": "2022-08-10T11:16:09.367",
"from": "3v1JUB1R1JLFtcKvHqD9QFqe2NXeBF53tp69FLPHYipTjNgLrV",
"to": "4aQYVWgohNvz1JNKQfSearaBR6a8vRfzkukigPhbPC4vn58TH8",
"value": "2000000000"
},
{
"id": "496754-54e003c546505786e628664dd4db095a6124bba245bc601c560c8529d152d968",
"block": "496754",
"date": "2022-08-10T05:45:13.564",
"from": "3v1JUB1R1JLFtcKvHqD9QFqe2NXeBF53tp69FLPHYipTjNgLrV",
"to": "3HyjqhNMxNtjytLWCSF6HdHtA62azb7wiQjz3yLsaTtqmTrDhT",
"value": "2000000000"
},
{
"id": "498634-e3f234b85b02cb9bb0942b5f14573b842733dbf2b5d1cfa11ab2f770952e0648",
"block": "498634",
"date": "2022-08-10T11:12:47.17",
"from": "3v1JUB1R1JLFtcKvHqD9QFqe2NXeBF53tp69FLPHYipTjNgLrV",
"to": "2xzR9ftc3phmgT14K9ge9rgxNnuS43iiEXpmJvkB6TQAKBG69C",
"value": "2000000000"
},
{
"id": "496752-2cd084f0acae30433b3618aa16117aeaaf4cb8876661bb36577dd72286f39933",
"block": "496752",
"date": "2022-08-10T05:44:38.569",
"from": "3v1JUB1R1JLFtcKvHqD9QFqe2NXeBF53tp69FLPHYipTjNgLrV",
"to": "3yikEbXmdM5cWP2DUAPfYT9FVg9gaJ3F93dwhRRn8hsxWFX27L",
"value": "2000000000"
}
]
},
"blockAccrueRewards": {
"nodes": [
{
"id": "499254-0",
"block": "499254",
"baker": "7",
"bakerReward": "0"
},
{
"id": "499253-0",
"block": "499253",
"baker": "9",
"bakerReward": "0"
},
{
"id": "499252-0",
"block": "499252",
"baker": "8",
"bakerReward": "0"
},
{
"id": "499251-0",
"block": "499251",
"baker": "3",
"bakerReward": "0"
},
{
"id": "499250-0",
"block": "499250",
"baker": "2",
"bakerReward": "0"
}
]
}
}
}
}
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.