--- page_source: https://juspay.io/in/docs/hyper-checkout/android/base-sdk-integration/open-hypercheckout-screen page_title: 3. Open Hypercheckout Screen --- # 3. Open Hypercheckout Screen Once the Hypercheckout screen is opened, your users can proceed with the transactions. Opening Hypercheckout requires a Server-to-Server request from Merchant to Juspay. The response of this should be forwarded to the Hypercheckout SDK in order to open the payment screen. > **Warning** > **This step should be done only once the final payable amount is available** ### Step 3.1. Fetch Process Payload The `process` function takes a JSONObject as argument. This argument is also known as process payload. In order to fetch process payload following steps should be followed: Make a request from Client to your Server with necessary order parameters Your server should call [Juspay's Session API](/hyper-checkout/android/base-sdk-integration/session)(Server-to-Server call) Session API will respond with a JSON object which contains process payload inside `sdk_payload` key Send the `sdk_payload` from your server to client #### Code Snippets: - #### Java Code Snippet: ```java // Note: Session API should only be called from merchant's server. Don't call it from client app // ----------------------------------------------------------------- private void run() throws IOException { JSONObject payload = new JSONObject(); // API Key Should never be used from client side, it should always be stored securely on server. // And all the API calls requiring API key should always be done from server String apiKey = ""; //Put your API Key Here String clientId = ""; // Put your clientID here String merchantId = ""; // Put your merchant ID here long randomOrderId = (long) (Math.random()*Math.pow(10,12)); String order_id = "test-" + Long.toString(randomOrderId); // Put you own order id here try{ // You can put your payload details here payload.put("order_id", order_id); // OrderID should be unique payload.put("amount", amountString); // Amount should be in strings e.g. "100.00" payload.put("customer_id", "9876543201"); // Customer ID should be unique for each user and should be a string payload.put("customer_email", "test@mail.com"); payload.put("customer_phone", "9876543201"); payload.put("payment_page_client_id", clientId); payload.put("action", "paymentPage"); payload.put("first_name", "john"); payload.put("last_name", "wick"); payload.put("description", "Order Description"); // For other payload params you can refer to the integration doc shared with you } catch (Exception e){ } OkHttpClient client = new OkHttpClient(); MediaType mediaType = MediaType.parse("application/json"); RequestBody requestBody = RequestBody.create(mediaType, payload.toString()); String authorization = "Basic " + Base64.getEncoder().encodeToString(apiKey.getBytes()); Request request = new Request.Builder() .url("https://api.juspay.in/session") .method("POST", requestBody) .addHeader("x-merchantid", merchantId) .addHeader("Authorization", authorization) .addHeader("Content-Type", "application/json") .build(); // Note: Session API should only be called from merchant's server. Don't call it from client app client.newCall(request).enqueue(new Callback() { @Override public void onFailure(Call call, IOException e) { call.cancel(); } @Override public void onResponse(Call call, Response response) throws IOException { try{ String processResponse = response.body().string(); JSONObject jsonObj = new JSONObject(processResponse); JSONObject sdkPayload = jsonObj.getJSONObject("sdk_payload"); CheckoutActivity.this.runOnUiThread(new Runnable() { @Override public void run() { startPayments(sdkPayload); } }); } catch (Exception e){ } } }); } // ----------------------------------------------------------------- ``` #### Kotlin Code Snippet: ```kotlin // Note: Session API should only be called from merchant's server. Don't call it from client app // ----------------------------------------------------------------- @Throws(IOException::class) fun run() { val payload = JSONObject() // API Key Should never be used from client side, it should always be stored securely on server. // And all the API calls requiring API key should always be done from server val apiKey = "" //Put your API Key Here val clientId = "" //Put your Client ID here val merchantId = "" // Put your Merchant ID here val randomOrderId = (Math.random() * Math.pow(10.0, 12.0)).toLong() val order_id = "test-" + java.lang.Long.toString(randomOrderId) try { payload.put("order_id", order_id) payload.put("amount", amountString) // Amount must be in string payload.put("customer_id", "9876543201") //Customer id should be in string payload.put("customer_email", "test@mail.com") payload.put("customer_phone", "9876543201") //Mobile number should be in string payload.put("payment_page_client_id", clientId) payload.put("action", "paymentPage") payload.put("offer_code", "testingCode") payload.put("first_name", "john") payload.put("last_name", "wick") payload.put("description", "Order Description") } catch (e: Exception) { } val client = OkHttpClient() val mediaType: MediaType? = "application/json".toMediaTypeOrNull() val requestBody: RequestBody = RequestBody.create(mediaType, payload.toString()) val authorization = "Basic " + Base64.getEncoder().encodeToString(apiKey.toByteArray()) val request: Request = Request.Builder() .url("https://api.juspay.in/session") .method("POST", requestBody) .addHeader("x-merchantid", merchantId) .addHeader("Authorization", authorization) .addHeader("Content-Type", "application/json") .build() // NOTE: DON'T COPY THIS CODE IN YOUR CLIENT APP // Juspay API should be called from your server, client app should only fetch the sdk_payload from your server client.newCall(request).enqueue(object : Callback { override fun onFailure(call: Call, e: IOException) { call.cancel() } @Throws(IOException::class) override fun onResponse(call: Call, response: Response) { try { val processResponse: String = response.body?.string() ?: "" val jsonObj = JSONObject(processResponse) val sdkPayload = jsonObj.getJSONObject("sdk_payload") runOnUiThread { startPayments(sdkPayload) } } catch (e: Exception) { } } }) } // ----------------------------------------------------------------- ``` ### Step 3.3. Call Process Function Pass the JSON inside `sdk_payload` obtained in `Step 3.1`, to `process`SDK``function`.` The process function is to be called using an instance of `HyperServiceHolder` #### Code Snippets: - #### Java Code Snippet: ```java private void startPayments(JSONObject sdk_payload) { // Make sure to use the same hyperServices instance which was created in // ProductsActivity.java Helper helper = new Helper(); helper.showSnackbar("Process Called!", coordinatorLayout); hyperServicesHolder.process(sdk_payload); } ``` #### Kotlin Code Snippet: ```kotlin fun startPayments(sdk_payload: JSONObject?) { // Make sure to use the same hyperServices instance which was created in // ProductsActivity.java showSnackbar("Process Called!") hyperServicesHolder?.process(sdk_payload) } ``` > **Warning** > As soon as you sign up with Juspay, we set you up with a Dummy PG automatically. Using this Dummy PG, you can run test transactions with a pre-configured set of cards. You may also configure the test credentials of the gateway and use the respective test cards for completing the transaction journey. Please refer to the [Test Resources](/hyper-checkout/android/resources/test-resources)page for more details.