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Add Cronos zkevm quick start
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jamesbayly committed Sep 13, 2024
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4 changes: 4 additions & 0 deletions docs/.vuepress/sidebar.ts
Original file line number Diff line number Diff line change
Expand Up @@ -103,6 +103,10 @@ export const getSidebar = (locale: string) =>
text: "Celo",
link: `${locale}/indexer/quickstart/quickstart_chains/celo.md`,
},
{
text: "Cronos zkEVM",
link: `${locale}/indexer/quickstart/quickstart_chains/cronos-zkevm.md`,
},
{
text: "Ethereum",
collapsible: true,
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8 changes: 6 additions & 2 deletions docs/indexer/quickstart/quickstart_chains/cosmos-cronos.md
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@@ -1,5 +1,9 @@
# Cronos Quick Start

::: tip Note
You can find the quickstart guide for Cronos' zkEVM network [here](./cronos-zkevm.md).
:::

The goal of this quick start guide is to adapt the standard starter project in the Cronos Network and then begin indexing all transfers of [Cro Crow Token](https://www.crocrow.com/).

<br/>
Expand Down Expand Up @@ -187,7 +191,7 @@ type TransferEventArgs = [string, string, BigNumber] & {

// Save all transfers
export async function handleTransfer(
log: EthereumLog<TransferEventArgs>,
log: EthereumLog<TransferEventArgs>
): Promise<void> {
const transfer = Transfer.create({
id: log.transactionHash,
Expand Down Expand Up @@ -216,7 +220,7 @@ type TransferEventArgs = [string, string, BigNumber] & {

// Save all transfers
export async function handleTransfer(
event: EthermintEvmEvent<TransferEventArgs>,
event: EthermintEvmEvent<TransferEventArgs>
): Promise<void> {
const transfer = Transfer.create({
id: event.transactionHash,
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249 changes: 249 additions & 0 deletions docs/indexer/quickstart/quickstart_chains/cronos-zkevm.md
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# Cronos zkEVM Quick Start

::: tip Note
You can find the quickstart guide for Cronos' Cosmos network [here](./cosmos-cronos.md).
:::

The goal of this quick start guide is to index all transfers and approval events from the CRO ([0xbcaa34ff9d5bfd0d948b18cf6bf39a882f4a1cbd](https://explorer.zkevm.cronos.org/tx/0xd580995835b5b0e142880dda3102adf70dd25641bf8bebdfdc25c65d9254f8a3)) on Cronos zkEVM Mainnet.

<!-- @include: ../snippets/evm-quickstart-reference.md -->

::: tip Note
The final code of this project can be found [here](https://github.com/subquery/ethereum-subql-starter/tree/main/Cronos/cronos-zkevm-starter).
:::

We use Ethereum packages, runtimes, and handlers (e.g. `@subql/node-ethereum`, `ethereum/Runtime`, and `ethereum/*Hander`) for Cronos zkEVM Mainnet. Since Cronos zkEVM is an EVM-compatible layer-2 scaling solution, we can use the core Ethereum framework to index it.

<!-- @include: ../snippets/evm-manifest-intro.md#level2 -->

As we are indexing all transfers and approvals from the CRO contract on Cronos zkEVM Mainnet, the first step is to import the contract abi definition which can be obtained from from any standard [ERC-20 contract](https://ethereum.org/en/developers/docs/standards/tokens/erc-20/). 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:**

```ts
{
dataSources: [
{
kind: EthereumDatasourceKind.Runtime,
startBlock: 40,
options: {
abi: "erc20",
// This is the contract address for CRO
address: "0xbcaa34ff9d5bfd0d948b18cf6bf39a882f4a1cbd",
},
assets: new Map([["erc20", { file: "./abis/erc20.abi.json" }]]),
mapping: {
file: "./dist/index.js",
handlers: [
{
kind: EthereumHandlerKind.Call, // We use ethereum handlers since Cronos zkEVM is EVM-compatible
handler: "handleTransaction",
filter: {
/**
* The function can either be the function fragment or signature
* function: '0x095ea7b3'
* function: '0x7ff36ab500000000000000000000000000000000000000000000000000000000'
*/
function: "approve(address spender, uint256 amount)",
},
},
{
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 [CRO token](https://explorer.zkevm.cronos.org/tx/0xd580995835b5b0e142880dda3102adf70dd25641bf8bebdfdc25c65d9254f8a3) on Cronos zkEVM Mainnet.

The code also indicates that you will be running a `handleLog` mapping function whenever there is a `Transfer` event being emitted from the [CRO Token](https://explorer.zkevm.cronos.org/tx/0xd580995835b5b0e142880dda3102adf70dd25641bf8bebdfdc25c65d9254f8a3) on Cronos zkEVM Mainnet.

<!-- @include: ../snippets/ethereum-manifest-note.md -->

<!-- @include: ../snippets/schema-intro.md#level2 -->

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.).

```graphql
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!
}
```

<!-- @include: ../snippets/note-on-entity-relationships.md -->

<!-- @include: ../snippets/evm-codegen.md -->

```ts
import { Approval, Transfer } from "../types";
import {
ApproveTransaction,
TransferLog,
} from "../types/abi-interfaces/Erc20Abi";
```

<!-- @include: ../snippets/schema-note.md -->

<!-- @include: ../snippets/mapping-intro.md#level2 -->

Navigate to the default mapping function in the `src/mappings` directory. You will be able to see two exported functions `handleLog` and `handleTransaction`:

```ts
import { Approval, Transfer } from "../types";
import {
ApproveTransaction,
TransferLog,
} from "../types/abi-interfaces/Erc20Abi";
import assert from "assert";

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_).

<!-- @include: ../snippets/ethereum-mapping-note.md -->

<!-- @include: ../snippets/build.md -->

<!-- @include: ../snippets/run-locally.md -->

<!-- @include: ../snippets/query-intro.md -->

```graphql
# Write your query or mutation here
{
query {
transfers(first: 5, orderBy: VALUE_DESC) {
totalCount
nodes {
id
blockHeight
from
to
value
contractAddress
}
}
}
}
```

You will see the result similar to below:

```json
{
"data": {
"query": {
"transfers": {
"totalCount": 5,
"nodes": [
{
"id": "0x625fd9f365a1601486c4176bc34cf0fdf04bf06b2393fd5dd43e8dd7a62d9ec5",
"blockHeight": "53",
"from": "0x0000000000000000000000000000000000000000",
"to": "0xb680c8F33f058163185AB6121F7582BAb57Ef8a7",
"value": "1000000000000000000000000",
"contractAddress": "0x28687c2A4638149745A0999D523f813f63b4786F"
},
{
"id": "0x32057c64d795a7f919925082b9cdc885e307e3a4590377154d746beadc557d3e",
"blockHeight": "62",
"from": "0xb680c8F33f058163185AB6121F7582BAb57Ef8a7",
"to": "0xCa8c45FE7FEDc3922266A1964cD8B8D29946A6A7",
"value": "300000000000000000000",
"contractAddress": "0x28687c2A4638149745A0999D523f813f63b4786F"
},
{
"id": "0xc591997f3217f6dfb6d4dad244126ad4ce245234fe452339b5ba8ad4d4264bdc",
"blockHeight": "66",
"from": "0xCa8c45FE7FEDc3922266A1964cD8B8D29946A6A7",
"to": "0xb21aBf688A6bE0975134a41e73bf2c8Da111fF0d",
"value": "50000000000000000000",
"contractAddress": "0x28687c2A4638149745A0999D523f813f63b4786F"
},
{
"id": "0x1e29daac0434ad4936391e7ba439146ecd9ff9d65869436d466a8e48963e420a",
"blockHeight": "67",
"from": "0xCa8c45FE7FEDc3922266A1964cD8B8D29946A6A7",
"to": "0xe42A2ADF3BEe1c195f4D72410421ad7908388A6a",
"value": "50000000000000000000",
"contractAddress": "0x28687c2A4638149745A0999D523f813f63b4786F"
},
{
"id": "0x73e95b32fe50daf7d0480a7dbd3005fcf22007ebff82fc6fa06a0c606783a0e3",
"blockHeight": "68",
"from": "0xe42A2ADF3BEe1c195f4D72410421ad7908388A6a",
"to": "0x6F715c294Dd78BB11aeB0817B44E2a0b06e3A0B4",
"value": "1000000000000000000",
"contractAddress": "0x28687c2A4638149745A0999D523f813f63b4786F"
}
]
}
}
}
}
```

::: tip Note
The final code of this project can be found [here](https://github.com/subquery/ethereum-subql-starter/tree/main/Cronos/cronos-zkevm-starter).
:::

<!-- @include: ../snippets/whats-next.md -->

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