---
page_source: https://juspay.io/in/docs/payment-page-enterprise/flutter/base-sdk-integration/initiating-sdk
page_title: 2. Initialize SDK
---


# 2. Initiating the SDK



To initialise the SDK, client needs to call the `initiate` SDK function. The initiate function call boots up the Hypercheckout SDK and makes it ready for all other operations

Follow the below steps to make an initiate SDK call

> **Warning**
> Initiate is to be called in the build function of the Home Screen widget. Not following this will lead to increased Hypercheckout latency.




### Step 2.1. Import HyperSDK


Import the HyperSDK namespace to get access to HyperServices class in your code

> **Error**
> Make sure that the MainActivity in Android inherits FlutterFragmentActivity instead of FlutterActivity. `android/app/src/main/kotlin/com/example/your_app_name/MainActivity.kt`





#### Code Snippets: -

#### Flutter Code Snippet:

```flutter
import 'package:flutter/material.dart';
import 'package:hypersdkflutter/hypersdkflutter.dart';
import 'package:flutter/services.dart';
import './screens/home.dart';

void main() {
  final hyperSDK = HyperSDK();
  runApp(MyApp(hyperSDK: hyperSDK));
}

class MyApp extends StatelessWidget {
  // Create Juspay Object
  // // block:start:create-hyper-sdk-instance
  final HyperSDK hyperSDK;
  // // block:end:create-hyper-sdk-instance
  const MyApp({Key? key, required this.hyperSDK}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    SystemChrome.setEnabledSystemUIMode(SystemUiMode.manual,
        overlays: [SystemUiOverlay.bottom]);
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: HomeScreen(
        hyperSDK: hyperSDK,
      ),
    );
  }
}

```



### Step 2.2. Create an instance of HyperServices


The Hypercheckout SDK exposes the `HyperServices` class. Create an object of this class for all upcoming operations



#### Code Snippets: -

#### Flutter Code Snippet:

```flutter
import 'package:flutter/material.dart';
import 'package:hypersdkflutter/hypersdkflutter.dart';
import 'package:flutter/services.dart';
import './screens/home.dart';

void main() {
  final hyperSDK = HyperSDK();
  runApp(MyApp(hyperSDK: hyperSDK));
}

class MyApp extends StatelessWidget {
  // Create Juspay Object
  // // block:start:create-hyper-sdk-instance
  final HyperSDK hyperSDK;
  // // block:end:create-hyper-sdk-instance
  const MyApp({Key? key, required this.hyperSDK}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    SystemChrome.setEnabledSystemUIMode(SystemUiMode.manual,
        overlays: [SystemUiOverlay.bottom]);
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: HomeScreen(
        hyperSDK: hyperSDK,
      ),
    );
  }
}

```



### Step 2.3. Create Initiate payload


Initiate takes two parameters as input. One of the parameter is a JSON object referred as `InitiatePayload`. This payload contains certain key value pairs used by the SDK to perform a successful initiate

Refer to the following table for information about the description and sample payload.


### Payload
- **RequestId**:
  - Description: Unique uuid-v4 string
  - Value: $requestId
  - Tags: String, Mandatory
- **Service**:
  - Description: Value: in.juspay.hyperpay
  - Tags: String, Mandatory
- **Payload**:
  - Description: Parameters
  - Value:
    - **Action**:
      - Description: Value: initiate
      - Tags: String, Mandatory
    - **MerchantId**:
      - Description: Unique merchant id shared during onboarding
      - Tags: String, Mandatory
    - **ClientId**:
      - Description: Unique Client id shared during onboarding
      - Tags: String, Mandatory
    - **Environment**:
      - Description: Environment to be used for the session. Accepted value is production
      - Tags: String, Mandatory
  - Tags: JSON, Mandatory




#### Code Snippets: -

#### Flutter Code Snippet:

```flutter
var initiatePayload = {
        "requestId": const Uuid().v4(),
        "service": "in.juspay.hyperpay",
        "payload": {
          "action": "initiate",
          "merchantId": "<MERCHANT_ID>",
          "clientId": "<CLIENT_ID>",
          "xRoutingId": "<X_ROUTING_ID>",
          "environment": "production"
        }
      };
```



### Step 2.4. Create CallbackHandler


During its lifecycle, SDK emits multiple events to communicate about the transaction status.

This callback handler is passed as the second argument to the initiate call.



#### Code Snippets: -

#### Flutter Code Snippet:

```flutter
void initiateCallbackHandler(MethodCall methodCall) {
    if (methodCall.method == "initiate_result") {
      // check initiate result
    }
  }
```



### Step 2.5. Call initiate


The final step is to call the `Initiate`function.

The initiate method takes two parameters: `InitiatePayload` and `HyperPaymentsCallbackAdapter`. Use the functions created in the above steps to create the parameters

> **Warning**
> Initiate is a fire-and-forget call. For every HyperService instance you should **call initiate only once.** 





#### Code Snippets: -

#### Flutter Code Snippet:

```flutter
await widget.hyperSDK.initiate(initiatePayload, initiateCallbackHandler);
```