--- page_source: https://docs.juspay.io/upi-inapp/flutter/interaction-with-sdk/initiating-the-sdk page_title: Initiating the SDK --- ## Initiating the SDK To initialise the SDK, client needs to call the `initiate` SDK API. The initiate api call boots up the SDK and makes it ready for all other operations Follow the below steps to make an initiate SDK call: ### Step 1 Import HyperSDK Import the HyperSDK namespace to get access to HyperServices class in your code #### Code Snippets: - #### Flutter Code Snippet: ```flutter import 'package:flutter/material.dart'; import 'package:hypersdk/hypersdk.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 Create an instance of HyperServices The 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:hypersdk/hypersdk.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 3 Create Initiate payload Initiate API 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. #### Code Snippets: - #### Flutter Code Snippet: ```flutter var initiatePayload = { { // block:start:generatingRequestId "requestId": const Uuid().v4(), // block:end:generatingRequestId "service": "in.juspay.hyperapi", "payload": { "action": "initiate", "merchantKeyId": "", "clientId": "", "signature": "", "signaturePayload": { "merchant_id": "stock", "customer_id": "abcde12345", "timestamp": "1668389349848" } "environment": "sandbox", "upiEnvironment": "sandbox" "issuingPsp": "YES_BIZ", "shouldCreateCustomer": true, "logLevel": 1 } } }; ``` ### Initiate Parameters ## Request Payload - **RequestId**: - Description: Unique uuid-v4 string - Value: $requestId - Tags: String, Mandatory - **Service**: - Description: Value: in.juspay.hyperapi - Tags: String, Mandatory - **Payload**: - Description: Parameters required to call Hyper SDK API - Value: - **Action**: - Description: Operation to be performed in the SDK. Should be initiate for this call. - Value: Value: initiate - Tags: String, Mandatory - **ClientId**: - Description: Client Id assigned by juspay. Usual convention is merchant_id - Value: Example: stock - Tags: String, Mandatory - **Environment**: - Description: Environment to be used for the session. Accepted values are 'sandbox' or 'production' - Value: Example: sandbox - Tags: String, Mandatory - **IssuingPsp**: - Description: Bank on which the merchant has been onboarded. - Value: Example: YES_BIZ - Tags: String, Mandatory - **MerchantKeyId**: - Description: Key ID to identify the public-private key pair used for signature generation. - Value: Example: 1234 - Tags: String, Mandatory - **Signature**: - Description: Generated signature for signature payload. See signature generation process in pre-requisites section. - Tags: String, Mandatory - **SignaturePayload**: - Description: Signature payload is a stringified JSON of the details mentioned in the below table. - Value: - **Merchant_id**: - Description: Unique identifier associated with an account created by juspay. - Value: Example: stock - Tags: String, Mandatory - **Customer_id**: - Description: Any unique reference associated with your customer. - Value: Example: abcde12345 - Tags: String, Mandatory - **Timestamp**: - Description: Time when request is created in milliseconds. - Value: Example: 1665996901100 - Tags: String, Mandatory - Tags: String, Mandatory - **ShouldCreateCustomer**: - Description: Value: true - Tags: Boolean, Mandatory - Tags: JSON, Mandatory ## Response Payload - **RequestId**: - Description: Unique uuid-v4 string - Value: $requestId - Tags: String, Mandatory - **Service**: - Description: Value: in.juspay.hyperapi - Tags: String, Mandatory - **Payload**: - Description: Parameters required to call Hyper SDK API - Value: - **Action**: - Description: Operation performed in the SDK. - Value: Value: initiate - Tags: String - **Status**: - Description: Status of the Operation. - Value: Possible values : SUCCESS / FAILURE - Tags: String - Tags: JSON, Mandatory > **Note** > [Click here](../miscellaneous/additional-parameters) for additional initiate parameters #### Code Snippets: - #### Flutter Code Snippet: ```flutter { "requestId": "8cbc3fad-8b3f-40c0-ae93-2d7e75a8624a", "service": "in.juspay.hyperapi", "payload": { "action": "initiate", "merchantKeyId": "", "clientId": "", "signature": "", "signaturePayload": "", "environment": "sandbox", "upiEnvironment": "sandbox" "issuingPsp": "YES_BIZ", "shouldCreateCustomer": true, "logLevel": 1 } } "signaturePayload": { "merchant_id": "stock", "customer_id": "abcde12345", "timestamp": "1668389349848" } ``` ### Step 4 Create CallbackHandler During its lifecycle, SDK emits multiple events to communicate about the transaction status. All of these events are received by an instance of `HyperPaymentsCallbackAdapter`. This callback handler is passed as the second argument to the initiate API call. #### Code Snippets: - #### Flutter Code Snippet: ```flutter void hyperSDKCallbackHandler(MethodCall methodCall) { switch (methodCall.method) { // block:start:show-loader case "show_loader": // Show some Loader break; // block:end:show-loader // block:start:hide-loader case "hide_loader": // Hide Loader break; // block:end:hide-loader // block:start:initiate-result case "initiate_result": // Get the response var args = {}; try { args = json.decode(methodCall.arguments); } catch (e) { print(e); } //Merchant handling break; // block:end:initiate-result // block:start:process-result case "process_result": // Get the response var args = {}; try { args = json.decode(methodCall.arguments); } catch (e) { print(e); } //Merchant handling break; // block:end:process-result // block:start:log-stream case "log_stream": // print data break; // block:end:log-stream // block:start:session-expiry case "session_expiry": // Handle Session Expiry break; // block:end:session-expiry } ``` ### Step 5 Call initiate The final step is to call the `Initiate SDK API`. 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, hyperSDKCallbackHandler); ```