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

# Biometrics Module

> Complete reference for the Biometrics (Face Verification) module

## Overview

The Biometrics module provides face verification and liveness detection capabilities through third-party provider integrations. It manages facial capture and verification to confirm that the person completing verification matches their identity document and is physically present (not a photo or video).

## Accessing the Module

The Biometrics module is accessed through the SDK's component factory:

```javascript theme={null}
const sdk = await OneSdk({
  mode: 'production',
  session: { token: 'your-token' }
});

// Create Biometrics component instance
const biometricsComponent = sdk.component('biometrics', options);
```

## Supported Providers

The Biometrics module supports multiple face verification providers:

| Provider | Value       | Learn More                             |
| -------- | ----------- | -------------------------------------- |
| Onfido   | `'onfido'`  | [onfido.com](https://onfido.com)       |
| Sumsub   | `'sumsub'`  | [sumsub.com](https://sumsub.com)       |
| Incode   | `'incode'`  | [incode.com](https://incode.com)       |
| IDVerse  | `'idverse'` | [idverse.com](https://www.idverse.com) |
| Daon     | `'daon'`    | [daon.com](https://www.daon.com)       |

<Note>
  Each provider has different capabilities, UI/UX, liveness detection methods, and device support. Visit the provider's website to understand their specific features and limitations.
</Note>

***

## Configuration Options

### Basic Configuration

```javascript theme={null}
const biometricsComponent = sdk.component('biometrics', {
  provider: {
    name: 'onfido'
  }
});
```

### Common Options

In addition to provider-specific settings, you can configure:

| Option                | Type      | Description                                              |
| --------------------- | --------- | -------------------------------------------------------- |
| `checkProcessingPool` | `object`  | Configure check processing polling behavior (optional)   |
| `is_synchronous`      | `boolean` | Whether to run biometric checks synchronously (optional) |

**Check Processing Pool:**

```javascript theme={null}
checkProcessingPool: {
  enabled: true,      // Enable polling for check results
  wait_time: 5,       // Wait time between polls (seconds)
  max_attempts: 1     // Maximum polling attempts
}
```

### Provider-Specific Options

#### Onfido Provider

```javascript theme={null}
const biometricsComponent = sdk.component('biometrics', {
  provider: {
    name: 'onfido',
    sdkVersion: '13.0.0',                // Onfido SDK version
    theme: 'light',                       // 'light' or 'dark'
    language: 'en_GB',                    // UI language (optional)
    translations: {                       // Custom translation strings (optional)
      // See Onfido documentation for translation keys
    },
    biometricsVariant: 'standard',        // 'standard', 'video', or 'motion'
    fallback: 'standard',                 // Fallback method: 'standard' or 'video'
    showExitButton: true,                 // Show exit button in UI
    crossDevicePolicy: 'disable',         // Cross-device flow: 'force' or 'disable'
    customUI: {                           // Custom UI configuration
      // See Onfido Custom UI options below
    }
  }
});
```

**Onfido Options:**

| Option                    | Type                                | Description                                                                                                                                                                                                                                                      |
| ------------------------- | ----------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `sdkVersion`              | `string`                            | Version of the Onfido SDK to use. Default: `'12'`. Refer to the [Onfido documentation](https://documentation.onfido.com/sdk/changelog/) for available versions.                                                                                                  |
| `theme`                   | `'light' \| 'dark'`                 | UI theme                                                                                                                                                                                                                                                         |
| `language`                | `string`                            | Language code for the Onfido UI. Requires `sdkVersion` 14 or later. See supported values below.                                                                                                                                                                  |
| `translations`            | `object`                            | Custom translation strings to override default Onfido copy. Keys must match Onfido's translation key schema — see the [Onfido language customisation docs](https://documentation.onfido.com/sdk/web/#language-customisation). Requires `sdkVersion` 14 or later. |
| `biometricsVariant`       | `'standard' \| 'video' \| 'motion'` | **Onfido-specific:** Biometric capture variant. `'standard'` uses photo-based liveness, `'video'` uses video liveness, `'motion'` uses motion-based liveness.                                                                                                    |
| `fallback`                | `'standard' \| 'video'`             | Fallback biometric method if primary method fails                                                                                                                                                                                                                |
| `showExitButton`          | `boolean`                           | Display exit button in the UI                                                                                                                                                                                                                                    |
| `crossDevicePolicy`       | `'force' \| 'disable'`              | Enable/disable cross-device flow                                                                                                                                                                                                                                 |
| `customUI`                | `object`                            | Custom UI styling configuration (see Custom UI section below)                                                                                                                                                                                                    |
| `onUserExit`              | `() => void`                        | Callback function when user exits the flow                                                                                                                                                                                                                       |
| `_crossDeviceLinkMethods` | `array`                             | Internal: cross-device link sharing methods                                                                                                                                                                                                                      |

**Supported `language` values:**

`ar`, `bg`, `cs`, `da`, `de`, `el`, `en_GB`, `en_US`, `es`, `es_419`, `es_DO`, `et`, `fa`, `fi`, `fr`, `fr_CA`, `he`, `hi`, `hr`, `hu`, `hy`, `id`, `it`, `ja`, `ko`, `lt`, `lv`, `ms`, `nl`, `no`, `pl`, `pt`, `pt_BR`, `ro`, `ru`, `sk`, `sl`, `sr`, `sv`, `th`, `tr`, `uk`, `vi`, `zh_CN`, `zh_TW`

**Onfido Custom UI Properties:**

The `customUI` object allows extensive styling customization:

```javascript theme={null}
customUI: {
  // Typography
  fontWeightBody: 400,
  fontSizeBody: '16px',
  fontSizeSubtitle: '18px',
  fontSizeTitle: '24px',

  // Colors - Background
  colorBackgroundSurfaceModal: '#FFFFFF',
  colorBackgroundIcon: '#353FF4',
  colorBackgroundInput: '#FFFFFF',

  // Colors - Content/Text
  colorContentBody: '#475467',
  colorContentTitle: '#101828',
  colorContentSubtitle: '#344054',
  colorContentInput: '#101828',

  // Colors - Buttons (Primary)
  colorContentButtonPrimaryText: '#FFFFFF',
  colorBackgroundButtonPrimary: '#353FF4',
  colorBackgroundButtonPrimaryHover: '#2835E5',
  colorBackgroundButtonPrimaryActive: '#1F2AD1',

  // Colors - Buttons (Secondary)
  colorContentButtonSecondaryText: '#344054',
  colorBackgroundButtonSecondary: '#FFFFFF',
  colorBackgroundButtonSecondaryHover: '#F9FAFB',
  colorBackgroundButtonSecondaryActive: '#F2F4F7',

  // Colors - Buttons (Tertiary)
  colorContentButtonTertiaryText: '#344054',

  // Borders
  borderRadiusButton: '8px',
  borderStyleSurfaceModal: '1px solid #E4E7EC',
  colorBorderInput: '#D0D5DD',
  colorInputOutline: '#353FF4',

  // Additional UI elements
  colorIcon: '#667085',
  colorBackgroundInfoPill: '#F2F4F7',
  colorContentInfoPill: '#344054',
  // ... see Onfido documentation for full list
}
```

***

#### Sumsub Provider

```javascript theme={null}
const biometricsComponent = sdk.component('biometrics', {
  provider: {
    name: 'sumsub',
    config: {
      theme: 'light',  // 'light' or 'dark'
      lang: 'en',      // Language code (optional)
      email: 'user@example.com',  // Pre-fill email (optional)
      phone: '+1234567890'        // Pre-fill phone (optional)
    },
    options: {
      addViewportTag: true,      // Add viewport meta tag
      adaptIframeHeight: true    // Auto-adjust iframe height
    }
  }
});
```

**Sumsub Options:**

| Option    | Type     | Description                                          |
| --------- | -------- | ---------------------------------------------------- |
| `config`  | `object` | Sumsub configuration object (see Config table below) |
| `options` | `object` | Sumsub SDK options (see Options table below)         |

**Sumsub Config Object:**

| Property | Type                | Required | Description                                  |
| -------- | ------------------- | -------- | -------------------------------------------- |
| `theme`  | `'dark' \| 'light'` | Yes      | UI theme                                     |
| `lang`   | `string`            | No       | Language code (e.g., `'en'`, `'es'`, `'fr'`) |
| `email`  | `string`            | No       | Pre-fill user's email address                |
| `phone`  | `string`            | No       | Pre-fill user's phone number                 |

**Sumsub Options Object:**

| Property            | Type      | Required | Description                                   |
| ------------------- | --------- | -------- | --------------------------------------------- |
| `addViewportTag`    | `boolean` | Yes      | Whether to add viewport meta tag to page      |
| `adaptIframeHeight` | `boolean` | Yes      | Whether to automatically adjust iframe height |

***

#### Incode Provider

```javascript theme={null}
const biometricsComponent = sdk.component('biometrics', {
  provider: {
    name: 'incode',
    sdkVersion: '1.0.0',  // Incode SDK version (optional)
    lang: 'es',           // UI language (optional)
    translations: {       // Custom translation strings (optional)
      // See Incode documentation for translation keys
    },
    renderCameraProps: {   // Raw options passed to the Incode SDK's renderCamera() call (optional)
      // See Incode Web SDK documentation for available renderCamera options
    }
  }
});
```

**Incode Options:**

| Option              | Type     | Description                                                                                                                                                                                                                                                                                                                                                                                                                                |
| ------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `sdkVersion`        | `string` | Version of the Incode SDK to use. Default: `'1.75.2'`. Refer to the [Incode documentation](https://docs.incode.com/docs/omni-web-sdk/release-notes) for available versions.                                                                                                                                                                                                                                                                |
| `lang`              | `string` | Language code for the Incode UI. See supported values below.                                                                                                                                                                                                                                                                                                                                                                               |
| `translations`      | `object` | Custom translation strings to override default Incode copy. See the [Incode language keys docs](https://documentation.identity.entrust.com/sdk/web/#identifying-language-keys) for available translation keys.                                                                                                                                                                                                                             |
| `renderCameraProps` | `object` | Advanced/raw options forwarded directly to the Incode SDK's `renderCamera()` call (optional). Unlike the OCR module's Incode provider, the Biometrics module's Incode provider does not expose a separate `renderCamera: { showDocSelector, showTutorial }` object — `renderCameraProps` is the only camera-rendering override available here, and it is passed straight through to the vendor SDK ahead of OneSDK's own capture handlers. |

**Supported `lang` values:**

`bn`, `ca`, `zh`, `hr`, `nl`, `en`, `en-BZ`, `en-DG`, `fr`, `de`, `ht`, `hi`, `hmn`, `hu`, `id`, `it`, `ms`, `pl`, `pt`, `pt-BR`, `pt-PT`, `ro`, `sr`, `sr-LATN`, `so`, `es`, `es-ES`, `tl-PH`, `tr`, `vi`

***

#### IDVerse Provider

```javascript theme={null}
const biometricsComponent = sdk.component('biometrics', {
  provider: {
    name: 'idverse',
    skipFaceScanIntro: false,     // Skip intro screen
    logoUrl: 'https://...',       // Custom logo URL
    retryCount: 3,                // Number of retry attempts
    skipLoad: false,              // Skip loading screen
    workerPathString: '/path',    // Custom worker path
    assetPathString: '/assets'    // Custom asset path
  }
});
```

**IDVerse Options:**

| Option              | Type      | Description                                        |
| ------------------- | --------- | -------------------------------------------------- |
| `skipFaceScanIntro` | `boolean` | Skip the face scan introduction screen (optional)  |
| `logoUrl`           | `string`  | URL to custom logo to display in the UI (optional) |
| `retryCount`        | `number`  | Number of retry attempts allowed (optional)        |
| `skipLoad`          | `boolean` | Skip the loading screen (optional)                 |
| `workerPathString`  | `string`  | Custom path to worker scripts (optional)           |
| `assetPathString`   | `string`  | Custom path to asset files (optional)              |

***

#### Daon Provider

```javascript theme={null}
const biometricsComponent = sdk.component('biometrics', {
  provider: {
    name: 'daon',
    products: ['faceLiveness']  // Array of Daon products to use
  }
});
```

**Daon Options:**

| Option     | Type       | Description                                 |
| ---------- | ---------- | ------------------------------------------- |
| `products` | `string[]` | Array of Daon product identifiers to enable |

***

## Methods

### `mount()`

Mounts the Biometrics component to a DOM element and starts the face verification flow.

**Signature:**

```typescript theme={null}
mount(domElementOrSelector: string | HTMLElement): void
```

**Parameters:**

| Parameter              | Type                    | Required | Description                                                                                                     |
| ---------------------- | ----------------------- | -------- | --------------------------------------------------------------------------------------------------------------- |
| `domElementOrSelector` | `string \| HTMLElement` | Yes      | CSS selector string (e.g., `'#biometrics-container'`) or HTMLElement object where the component will be mounted |

**Description:**
Mounts the biometric capture interface to the specified DOM element and initiates the face verification flow. The provider's camera interface will be displayed within this element.

**Example:**

```javascript theme={null}
// Mount to element by ID
biometricsComponent.mount('#biometrics-container');

// Mount to element reference
const container = document.getElementById('biometrics-container');
biometricsComponent.mount(container);
```

***

### `unmount()`

Unmounts the Biometrics component from the DOM.

**Signature:**

```typescript theme={null}
unmount(): void
```

**Description:**
Removes the Biometrics component from the DOM and cleans up resources, including stopping camera access. Call this when the user navigates away or the verification flow is complete.

**Example:**

```javascript theme={null}
biometricsComponent.unmount();
```

***

## Events

The Biometrics module emits events throughout the verification lifecycle:

<Warning>
  **Provider-Specific Behavior:** Events and statuses vary by provider. Not all providers emit all events, and some events are provider-specific. Always test with your chosen provider to understand which events are emitted and when.
</Warning>

### `vendor_sdk_loaded`

<Note>
  **Common Event:** This event is emitted by all vendor-based modules (IDV, OCR, Biometrics, Device).
</Note>

Emitted when the provider's SDK has been successfully loaded.

```typescript theme={null}
biometricsComponent.on('vendor_sdk_loaded', ({ vendor }) => {
  console.log('SDK loaded for:', vendor);
});
```

**Parameters:**

| Parameter | Type     | Description                                                      |
| --------- | -------- | ---------------------------------------------------------------- |
| `vendor`  | `string` | The provider whose SDK was loaded (`'onfido'`, `'sumsub'`, etc.) |

***

### `vendor_sdk_failed_loading`

<Note>
  **Common Event:** This event is emitted by all vendor-based modules (IDV, OCR, Biometrics, Device).
</Note>

Emitted when the provider's SDK fails to load.

```typescript theme={null}
biometricsComponent.on('vendor_sdk_failed_loading', ({ vendor, errorObject }) => {
  console.error(`Failed to load ${vendor} SDK:`, errorObject);
});
```

**Parameters:**

| Parameter     | Type      | Description                            |
| ------------- | --------- | -------------------------------------- |
| `vendor`      | `string`  | The provider whose SDK failed to load  |
| `errorObject` | `unknown` | The error that occurred during loading |

***

### `session_data_generated`

Emitted when a biometric verification session has been created with the provider.

```typescript theme={null}
biometricsComponent.on('session_data_generated', ({ session }) => {
  console.log('Session created for entity:', session.entityId);
  console.log('Vendor parameters:', session.vendorParameters);
});
```

**Parameters:**

| Parameter                  | Type      | Description                                 |
| -------------------------- | --------- | ------------------------------------------- |
| `session.entityId`         | `string`  | The entity ID for this verification session |
| `session.vendorParameters` | `unknown` | Provider-specific session parameters        |

***

### `session_data_failed_loading`

Emitted when session data fails to load.

```typescript theme={null}
biometricsComponent.on('session_data_failed_loading', ({ code, message }) => {
  console.error('Session failed:', message);
});
```

**Parameters:**

| Parameter | Type      | Description                          |
| --------- | --------- | ------------------------------------ |
| `code`    | `unknown` | Optional error code                  |
| `message` | `string`  | Error message describing the failure |

***

### `ready`

Emitted when the biometric capture interface is ready for user interaction.

```typescript theme={null}
biometricsComponent.on('ready', ({ domElement }) => {
  console.log('Biometrics UI ready');
  // Camera capture can begin
});
```

**Parameters:**

| Parameter    | Type          | Description                                    |
| ------------ | ------------- | ---------------------------------------------- |
| `domElement` | `HTMLElement` | The DOM element where the component is mounted |

***

### `input_required`

Emitted when a non-positive flow has occurred but is likely recoverable by retrying.

```typescript theme={null}
biometricsComponent.on('input_required', (info, status) => {
  console.log('Input required. Status:', status);
  console.log('User can retry to continue verification');

  // Handle different statuses
  showRetryMessage(status);
});
```

**Parameters:**

| Parameter       | Type                                                                                                             | Description                                                     |
| --------------- | ---------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------- |
| `info.entityId` | `string \| null`                                                                                                 | The entity ID, or null if not yet available                     |
| `status`        | [`IDVStatus`](/docs/sdk-reference/idv-module#statuses) \| [`OCRStatus`](/docs/sdk-reference/ocr-module#statuses) | The current verification status indicating what input is needed |

**Description:**
This event indicates that verification cannot proceed in its current state, but the issue is typically recoverable. Common scenarios include:

* User closed the verification session
* Session timeout occurred
* Waiting for selfie capture
* Awaiting user consent
* Camera permission denied

The user can typically retry the verification process to resolve these issues.

***

### `detection_complete`

Emitted when the biometric capture process has completed successfully.

```typescript theme={null}
biometricsComponent.on('detection_complete', ({ provider }) => {
  console.log('Face captured successfully by:', provider);
  showMessage('Processing your biometric data...');
});
```

**Parameters:**

| Parameter  | Type     | Description                                                          |
| ---------- | -------- | -------------------------------------------------------------------- |
| `provider` | `string` | The provider that completed the capture (optional, may be undefined) |

***

### `detection_failed`

Emitted when the biometric capture process fails.

```typescript theme={null}
biometricsComponent.on('detection_failed', ({ message }) => {
  console.error('Capture failed:', message);
  showError(message || 'Biometric capture failed. Please try again.');
});
```

**Parameters:**

| Parameter | Type     | Description                                            |
| --------- | -------- | ------------------------------------------------------ |
| `message` | `string` | Error message describing why capture failed (optional) |

***

### `processing`

Emitted when biometric data is being processed by the provider.

```typescript theme={null}
biometricsComponent.on('processing', ({ checkStatus, entityId }) => {
  console.log('Processing biometric data:', checkStatus);
  showLoadingIndicator();
});
```

**Parameters:**

| Parameter     | Type                                                   | Description                               |
| ------------- | ------------------------------------------------------ | ----------------------------------------- |
| `checkStatus` | [`IDVStatus`](/docs/sdk-reference/idv-module#statuses) | The current status of the biometric check |
| `entityId`    | `string \| null`                                       | The entity ID being verified              |

***

### `results`

Emitted when the biometric verification process completes with results.

```typescript theme={null}
biometricsComponent.on('results', ({ provider, checkStatus, document, entityId }) => {
  console.log('Verification complete');
  console.log('Provider:', provider);
  console.log('Status:', checkStatus);

  if (checkStatus === 'COMPLETE') {
    console.log('✓ Biometric verification passed');
    navigateToSuccess();
  } else {
    console.log('✗ Verification status:', checkStatus);
    handleFailure(checkStatus);
  }
});
```

**Parameters:**

| Parameter     | Type                                                   | Description                                         |
| ------------- | ------------------------------------------------------ | --------------------------------------------------- |
| `provider`    | `string \| null`                                       | The provider that performed verification (optional) |
| `checkStatus` | [`IDVStatus`](/docs/sdk-reference/idv-module#statuses) | Final verification status                           |
| `document`    | `Document \| null`                                     | Associated document data, if any                    |
| `entityId`    | `string \| null`                                       | The entity ID that was verified                     |

***

### `session_closed`

Emitted when the verification session is closed normally.

```typescript theme={null}
biometricsComponent.on('session_closed', () => {
  console.log('Biometric session closed');
  cleanup();
});
```

**Parameters:** None

***

### `session_interrupted`

Emitted when the verification session is interrupted by the user.

```typescript theme={null}
biometricsComponent.on('session_interrupted', (interruptInfo) => {
  console.log('User interrupted verification');
  saveProgress();
  showMessage('You can resume verification later');
});
```

**Parameters:**

| Parameter       | Type     | Description                        |
| --------------- | -------- | ---------------------------------- |
| `interruptInfo` | `object` | Information about the interruption |

<Note>
  **Provider-Specific:**

  * **Onfido:** Emits this when the verification modal is closed.
</Note>

***

### `vendor_event`

Emitted for provider-specific events that don't map to standard events.

```typescript theme={null}
biometricsComponent.on('vendor_event', (eventData) => {
  console.log('Provider event:', eventData);
  // Handle provider-specific logic
});
```

**Parameters:**

| Parameter   | Type     | Description                  |
| ----------- | -------- | ---------------------------- |
| `eventData` | `object` | Provider-specific event data |

***

## Complete Example

```javascript theme={null}
import OneSdk from '@frankieone/one-sdk';

async function performBiometricVerification() {
  try {
    // Initialize SDK
    const sdk = await OneSdk({
      mode: 'production',
      session: { token: await getSessionToken() }
    });

    // Create Biometrics component with Onfido provider
    const biometricsComponent = sdk.component('biometrics', {
      provider: {
        name: 'onfido',
        theme: 'light',
        biometricsVariant: 'standard',
        showExitButton: true,
        fallback: 'video'
      },
      checkProcessingPool: {
        enabled: true,
        wait_time: 5,
        max_attempts: 3
      }
    });

    // Set up event listeners
    biometricsComponent.on('vendor_sdk_loaded', ({ vendor }) => {
      console.log(`${vendor} SDK loaded successfully`);
    });

    biometricsComponent.on('vendor_sdk_failed_loading', ({ vendor, errorObject }) => {
      console.error(`Failed to load ${vendor} SDK:`, errorObject);
      showError('Biometric verification unavailable. Please try again later.');
    });

    biometricsComponent.on('session_data_generated', ({ session }) => {
      console.log('Biometric session created for:', session.entityId);
    });

    biometricsComponent.on('session_data_failed_loading', ({ message }) => {
      console.error('Session failed:', message);
      showError('Failed to start biometric verification');
    });

    biometricsComponent.on('ready', ({ domElement }) => {
      console.log('Camera ready, please position your face');
      showInstruction('Position your face in the frame');
    });

    biometricsComponent.on('input_required', (info, status) => {
      console.log('Input required:', status);
      showRetryButton();
    });

    biometricsComponent.on('detection_complete', ({ provider }) => {
      console.log('Face captured successfully');
      showMessage('Processing your biometric data...');
      hideCamera();
    });

    biometricsComponent.on('detection_failed', ({ message }) => {
      console.error('Capture failed:', message);
      showError(message || 'Failed to capture face. Please try again.');
    });

    biometricsComponent.on('processing', ({ checkStatus }) => {
      console.log('Processing:', checkStatus);
      showLoadingIndicator();
    });

    biometricsComponent.on('results', ({ checkStatus, entityId }) => {
      console.log('Verification complete');

      if (checkStatus === 'COMPLETE') {
        console.log('✓ Biometric verification passed');
        navigateToSuccess();
      } else if (checkStatus === 'FAILED') {
        console.log('✗ Biometric verification failed');
        showFailureScreen();
      } else {
        console.log('Status:', checkStatus);
        handleOtherStatus(checkStatus);
      }
    });

    biometricsComponent.on('session_interrupted', () => {
      console.log('User interrupted verification');
      saveProgress();
    });

    biometricsComponent.on('session_closed', () => {
      console.log('Session closed');
      cleanup();
    });

    // Mount and start biometric verification
    biometricsComponent.mount('#biometrics-container');

  } catch (error) {
    console.error('Biometrics initialization failed:', error);
    throw error;
  }
}
```

***

## Best Practices

1. **Handle all events, not just `results`** - The `results` event only fires with `COMPLETE` or `FAILED`. Also listen to `input_required` (for recoverable states like INCOMPLETE or INTERRUPTED), `error` (for system failures), and `processing` (for intermediate states).

2. **Set up event listeners before mounting** - Register all event handlers before calling `mount()` to avoid missing events.

3. **Unmount on navigation** - Always call `unmount()` when the user leaves the page to clean up resources.

4. **Provider-specific configuration** - Review each provider's documentation for optimal configuration.

5. **Error handling** - Always listen to the `error` event and provide user-friendly error messages.

***

## Common Issues

### Component not displaying

Ensure the mount element exists in the DOM and has sufficient size:

```css theme={null}
#biometrics-container {
  width: 100%;
  min-height: 600px;
}
```

### Session data failed to load

This usually means the backend session setup failed. Ensure your backend is correctly generating biometric verification tokens.

### Provider-specific errors

Check the `vendor_event` emissions for provider-specific error details and consult the provider's documentation.

***

## Related Resources

* [SDK Initialization](/docs/sdk-reference/sdk-initialization) - OneSDK setup and configuration
* [IDV Module](/docs/sdk-reference/idv-module) - Combined document + biometric verification
* [OCR Module](/docs/sdk-reference/ocr-module) - Document capture (often used before biometrics)
* [Individual Module](/docs/sdk-reference/individual-module) - Entity data management