> For the complete documentation index, see [llms.txt](https://docs.nlx.ai/platform/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nlx.ai/platform/developers/voice+-api/track/sdk.md).

# SDK

{% hint style="info" %}
The functionality of this SDK will soon move to the [Touchpoint SDK](/platform/developers/conversation-sdk/touchpoint.md).
{% endhint %}

The Voice+ Core SDK ([`@nlxai/voice-plus-core`](https://github.com/nlxai/sdk/tree/main/packages/voice-plus-core)) is a lightweight JavaScript library designed to simplify the integration of Voice+ multimodal features into your web applications.

It handles authentication headers, session management, and API calls to the Voice+ Track API automatically, allowing you to focus on tracking journey steps and synchronizing state.

### Installation

Install the package via npm or yarn:

```bash
npm install @nlxai/voice-plus-core
# or
yarn add @nlxai/voice-plus-core
```

### Initialization

To start tracking a journey, import the `create` function and initialize a client. You will need the credentials found in your Voice+ journey configuration.

```javascript
import { create } from "@nlxai/voice-plus-core";

// Initialize the client
const client = create({
  apiKey: "YOUR_VOICE_PLUS_API_KEY",    // Specific Voice+ Key (x-api-key)
  workspaceId: "YOUR_WORKSPACE_ID",     // Your Workspace ID (x-nlx-id)
  scriptId: "YOUR_SCRIPT_ID",           // The UUID of the journey/script
  conversationId: "XXXXXXXXX",          // Conversation ID for the active voice session
  languageCode: "en-US"                 // Language code (e.g., en-US)
});
```

{% hint style="info" %}
The `conversationId` is typically passed to your web application via a URL parameter (e.g., sent via SMS during the call) or through a push notification.
{% endhint %}

### Tracking steps

Use the `sendStep` method to notify the Voice+ application that a user has reached a specific point in the journey or performed an action.

**Basic usage**

```javascript
// distinct step UUID defined in your Voice+ script
const STEP_ID = "550e8400-e29b-41d4-a716-446655440000";

try {
  await client.sendStep(STEP_ID);
  console.log("Step tracked successfully");
} catch (error) {
  console.error("Failed to track step", error);
}
```

**Sending context**

You can pass an optional context object to send data back to the voice bot (e.g., form selections, user choices).

```javascript
const context = {
  selectedSeat: "4A",
  mealPreference: "vegetarian"
};

await client.sendStep(STEP_ID, context);
```

**With trigger description**

You can also provide a description of what triggered the step for analytics debugging.

```javascript
await client.sendStep({
  stepId: STEP_ID,
  stepTriggerDescription: "User clicked the 'Confirm Seat' button"
});
```

### API Reference

#### **`create(config)`**

Creates a new Voice+ client instance.

| Parameter               | Type   | Description                                      |
| ----------------------- | ------ | ------------------------------------------------ |
| `config.apiKey`         | String | **Required.** The Voice+ API Key.                |
| `config.workspaceId`    | String | **Required.** The NLX Workspace ID.              |
| `config.scriptId`       | UUID   | **Required.** The Journey/Script ID.             |
| `config.conversationId` | String | **Required.** The active session ID.             |
| `config.languageCode`   | String | **Required.** IETF language tag (e.g., `en-US`). |

#### `client.sendStep(stepId, [context])`

| Parameter | Type   | Description                                   |
| --------- | ------ | --------------------------------------------- |
| `stepId`  | UUID   | **Required.** The ID of the step to track.    |
| `context` | Object | (Optional) JSON object containing state data. |


---

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