> ## Documentation Index
> Fetch the complete documentation index at: https://nexaid.hashkey.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Example

This part will help you understand the fundamental steps to integrate NexaID Network-JS-SDK and complete a basic data verification process through your application.

### Prerequisites

Before you begin, ensure you have the following:

* A valid Template ID (obtainable from the [NexaID Developer Hub](https://nexaid.hashkey.com/))
* The SDK installed. (see [Installation Guide](/docs/build/dapp-integration/installation)
  for instructions)

### Key Features

#### **1. SDK Initialization**

Connect to specified blockchain networks.

Function Name: `init`

##### **Parameter Description**:

| Parameter Name | Type       | Required | Description                                                                                                                                                                                        |
| -------------- | ---------- | -------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `provider`     | `Provider` | Yes      | Web3 provider, can be:  <br />- An instance of `ethers.providers.JsonRpcProvider`  <br />- An instance of `ethers.providers.Web3Provider`  <br />- An instance of `ethers.providers.JsonRpcSigner` |
| `chainId`      | `number`   | Yes      | The blockchain network ID to connect to. Must be one of [the supported chain IDs](/docs/build/dapp-integration/example#6-list-of-supported-chains)                                                      |

#### **2. Task Submission**

Submit tasks to require an attestation from the network.

Function Name: `submitTask`

##### **Parameter Description**:

| Parameter Name | Type     | Required | Description  |
| -------------- | -------- | -------- | ------------ |
| `templateId`   | `string` | Yes      | Template ID  |
| `address`      | `string` | Yes      | User address |

#### **3. Attestation Execution**

Execute the zkTLS protocol with the network attestor node, and return an attestation issued by the attestor node.

Function Name: `attest`

##### **Parameter Description**:

| Parameter Name   | Type       | Required | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| ---------------- | ---------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `templateId`     | `string`   | Yes      | Template ID                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| `address`        | `string`   | Yes      | User address                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| `taskId`         | `string`   | Yes      | Task ID                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| `taskTxHash`     | `string`   | Yes      | Task transaction hash                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| `taskAttestors`  | `string[]` | Yes      | Array of attestor IDs                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| `additionParams` | `string`   | No       | Extended parameters in JSON format. Developers can include custom business parameters (e.g., user IDs, session info),These parameters will be returned with the final results `const additionParams = JSON.stringify({ YOUR_CUSTOM_KEY: "YOUR_CUSTOM_VALUE" })`                                                                                                                                                                                                                       |
| `attMode`        | `string`   | No       | proxytls or mpctls,default is proxytls. you can refer to [Overview](/docs/nexaid/overview-of-zktls)<br /> section for more details.                                                                                                                                                                                                                                                                                                                                                        |
| `attConditions`  | `Array`    | No       | By default, the zkTLS SDK returns plaintext verification results. You can also define verification logics for hashed results or condition-based results. Example hashed result: `const attConditions = [[{ field: "YOUR_CUSTOM_DATA_FIELD", op: "SHA256" }]]`. Example condition result: `const attConditions = [[{ field: "YOUR_CUSTOM_DATA_FIELD", op: ">", value: "YOUR_CUSTOM_TARGET_DATA_VALUE" }]]`. For the full explanation, see [zkTLS Operations](/docs/build/zktls-operations). |

#### **4. Verify & Poll Task Result**

Verify and poll task results. The function is additionally provided for any use case that requires to double check the validity of a created attestation through NexaID contracts.

Function Name: `verifyAndPollTaskResult`

##### **Parameter Description**:

| Parameter Name | Type     | Required | Description                                                 |
| -------------- | -------- | -------- | ----------------------------------------------------------- |
| `taskId`       | `string` | Yes      | The ID of the task to poll                                  |
| `reportTxHash` | `string` | No       | Report transaction hash (optional)                          |
| `intervalMs`   | `number` | No       | Polling interval in milliseconds, default is 2000           |
| `timeoutMs`    | `number` | No       | Total timeout duration in milliseconds, default is 1 minute |

#### **5. Balance Withdrawal**

Retrieve the fees for unsettled tasks.

Function Name: `withdrawBalance`

##### **Parameter Description**:

| Parameter Name | Type          | Required | Description                             |
| -------------- | ------------- | -------- | --------------------------------------- |
| `tokenSymbol`  | `TokenSymbol` | No       | Token type to withdraw, default is ETH  |
| `limit`        | `number`      | No       | Withdrawal amount limit, default is 100 |

#### **6. List of Supported Chains**

Property Name：`supportedChainIds`

Currently supports **HashKey Chain Testnet**, additional chains will be added in upcoming releases.

### Using Attestations in zkVM

To retrieve a proof validated using hashed verification logic, you may use **getAllJsonResponse** to collect the associated HTTP response payloads. These two components — the attestation (***hashed data***) and the HTTP responses (***raw data***) — can then be jointly submitted to the zkVM for further computation and verification. For more details about hashed and condition-based logic, see [zkTLS Operations](/docs/build/zktls-operations).

```javascript theme={null}
const attestParams = {
  ...submitTaskParams,
  ...submitTaskResult,
  attConditions: [
    [
      {
        field: "YOUR_FIELD_NAME",
        op: "SHA256",
      },
    ],
  ],
  allJsonResponseFlag: "true", // optional, default is "false"
};

const attestResult = await nexaIDNetwork.attest(attestParams);
const allJsonResponse = await nexaIDNetwork.getAllJsonResponse(
  attestResult[0].taskId
);
```

## Complete Example

```javascript theme={null}
import { NexaIDNetwork } from "@nexaid/network-js-sdk";

async function main() {
  const provider = window.ethereum;
  const nexaIDNetwork = new NexaIDNetwork();

  console.log(nexaIDNetwork.supportedChainIds); // [133]

  try {
    // 1. Initialize
    await nexaIDNetwork.init(provider, 133); // HashKey Chain Testnet
    console.log("SDK initialized");

    // 2. Submit task, set TemplateID and user address
    const submitTaskParams = {
      templateId: "YOUR_TEMPLATEID",
      address: "YOUR_USER_ADDRESS",
    };
    const submitTaskResult = await nexaIDNetwork.submitTask(submitTaskParams);
    console.log("Task submitted:", submitTaskResult);

    // 3. Perform attestation
    const attestParams = {
      ...submitTaskParams,
      ...submitTaskResult,
      // extendedParams: JSON.stringify({ attUrlOptimization: true }),
      // Optional: optimize the URL of attestation.
    };
    const attestResult = await nexaIDNetwork.attest(attestParams);
    console.log("Attestation completed:", attestResult);

    // 4. Verify and poll task result
    const verifyAndPollTaskResultParams = {
      taskId: attestResult[0].taskId,
      reportTxHash: attestResult[0].reportTxHash,
    };
    const taskResult = await nexaIDNetwork.verifyAndPollTaskResult(
      verifyAndPollTaskResultParams
    );
    console.log("Final result:", taskResult);

    // Optional withdrawal
    // const settledTaskIds = await nexaIDNetwork.withdrawBalance();
    // console.log("Withdrawn:", settledTaskIds);
  } catch (error) {
    console.error("Main flow error:", error);
  }
}

main();
```

### Understanding the Attestation Structure

When a successful data verification process is completed, you will receive an zkTLS attestation (proof) from the attestor.

For more information about the attestation structure, see the [section](/docs/build/misc/attestation-structure)
.

### Error Codes

We have defined several error codes in the SDK. If an error occurs during the data verification process, you can refer to the [error code list](/docs/build/misc/error-code)
for troubleshooting.