> ## Documentation Index > Fetch the complete documentation index at: https://developer.transactbridge.com/llms.txt > Use this file to discover all available pages before exploring further. # v1.0 ## 1. Initialization Initialize the SDK in your Application's `onCreate` method. This only needs to be done once when your application starts. The SDK uses a singleton pattern for all interactions. ```java theme={null} import com.transactbridge.sdk.TransactBridge; import android.app.Application; public class MyApplication extends Application { @Override public void onCreate() { super.onCreate(); // Initialize the TransactBridge singleton TransactBridge.getInstance().initialize(this, TransactBridge.LogLevel.ERROR); // Or LogLevel.VERBOSE, LogLevel.NONE } } ``` ## 2. Configuration You can configure the SDK instance after initialization. ### 2.1. Log Level The SDK provides three log levels: * `TransactBridge.LogLevel.VERBOSE`: Logs all messages. * `TransactBridge.LogLevel.ERROR`: Logs only error messages. This is the default. * `TransactBridge.LogLevel.NONE`: Disables all logging. ```java theme={null} // Set the log level at any time TransactBridge.getInstance().setLogLevel(TransactBridge.LogLevel.VERBOSE); ``` ### 2.2. Auto Close By default, the checkout view will close automatically when the flow is complete. You can disable this behavior globally: ```java theme={null} TransactBridge.getInstance().setAutoClose(false); ``` You can also override this setting for a specific session using the `Builder`. ## 3. Usage To start a checkout session, create a `TransactBridge.Builder` to configure listeners and session-specific settings. Then, call the `open()` method on the `TransactBridge` singleton instance. ```java theme={null} import com.transactbridge.sdk.TransactBridge; import com.transactbridge.sdk.listeners.*; import android.os.Bundle; // ... inside your Activity or Fragment TransactBridge.Builder builder = new TransactBridge.Builder() .setTransactionListener(transactionData -> { // Handle transaction data }) .setSessionListener(sessionData -> { // Handle session data }) .setCloseListener(() -> { // Handle close event }) .setErrorListener((errorCode, errorMessage, extras) -> { // Handle error }) .setAutoClose(true); // Optional: Override global setting for this session // Start the checkout session TransactBridge.getInstance().open(this, "YOUR_CHECKOUT_URL", builder); ``` ## 4. Event Handling The SDK uses listeners to notify your application of events for a specific session. ### 4.1. TransactionListener * `onTxnData(TransactionData transactionData)`: Called with transaction details. **TransactionData** | Method | Description | | ------------------- | ------------------------------------------------ | | `getTxnIds()` | Returns a `List` of transaction IDs. | | `getCheckoutData()` | Returns `CheckoutData` with payment method info. | ### 4.2. SessionListener * `onSessionData(SessionData sessionData)`: Called for session-related events. **SessionData** | Method | Description | | ------------- | ------------------------------------------------ | | `getStatus()` | Returns the status of the session as a `String`. | | `getTbId()` | Returns the TransactBridge ID as a `String`. | | `getType()` | Returns the type of session event as a `String`. | ### 4.3. CloseListener * `onClose()`: Called when the sdk is closed. ### 4.4. TransactBridgeErrorListener * `onError(int errorCode, String message, @Nullable Bundle extras)`: Called when an error occurs. The `errorCode` provides a specific reason for the error. | Error Code | Value | Description | | ---------------------------- | ----- | --------------------------------------------------------------------------------------------------------------- | | `ERROR_INTENT_LAUNCH_FAILED` | 1001 | Failed to launch an external application, such as a UPI or other payment app. | | `ERROR_WEBVIEW_LOAD_FAILED` | 1002 | The WebView failed to load the checkout page due to a network error, SSL issue, or other configuration problem. | | `ERROR_INVALID_URL` | 1003 | The URL provided when opening the checkout session was invalid. | ### 4.5. Advanced Event Handling The SDK handles several types of events automatically to provide a smooth user experience. * **URL Redirection**: When a user action in the checkout flow needs to navigate to an external webpage, the SDK automatically opens it in a secure Chrome Custom Tab. This keeps the user within the context of your app while providing a full browser experience. * **Intent Redirection**: For payment methods that require invoking another app (like a UPI payment app), the SDK will automatically fire the necessary Android Intent to switch to that app. * **Invoice Downloads**: If the checkout process provides an invoice for download, the SDK will handle the download intent to allow the user to save the invoice. ### 4.6. Deep Link Configuration The SDK has built-in support for handling deep links. If your app's Activity that integrates the TransactBridge SDK uses a `launchMode` other than `standard` (e.g., `singleTop`, `singleTask`, or `singleInstance`), you must forward deep link intents to the SDK. In your Activity, override the `onNewIntent` method and pass the `Intent` to the `TransactBridge.handleDeepLink()` method: ```java theme={null} @Override protected void onNewIntent(Intent intent) { super.onNewIntent(intent); TransactBridge.handleDeepLink(intent); } ``` ## 5. API Reference ### TransactBridge Singleton | Method | Description | | ----------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `getInstance()` | Returns the singleton instance of the SDK. | | `initialize(Context, LogLevel)` | Initializes the SDK. Should be called once. | | `setLogLevel(LogLevel)` | Sets the log level for the SDK. | | `setAutoClose(boolean)` | Enables or disables automatic closing globally. | | `open(Context, String, TransactBridge.Builder)` | Opens the checkout flow with session-specific listeners and settings. | | `close()` | Manually closes the `sdk`. (Static method) **Note:** To prevent potential deadlocks, you should not call `TransactBridge.close()` from within the `SessionListener.onSessionData()` callback. The SDK will ignore any `close()` requests made from this callback. | ### TransactBridge.Builder The builder is used to configure a single checkout session. | Method | Description | | ----------------------------- | ------------------------------------------------------------------ | | `setTransactionListener(...)` | Sets the `TransactionListener` for the session. | | `setSessionListener(...)` | Sets the `SessionListener` for the session. | | `setCloseListener(...)` | Sets the `CloseListener` for the session. | | `setErrorListener(...)` | Sets the `TransactBridgeErrorListener` for the session. | | `setAutoClose(boolean)` | Overrides the global auto-close setting for this specific session. |