> This is a page from the ElevenLabs documentation. For a complete page index, fetch https://elevenlabs.io/docs/llms.txt. For the full documentation in a single file, fetch https://elevenlabs.io/docs/llms-full.txt.

# WebSocket

> **Note**
>
> This documentation is for developers integrating directly with the ElevenLabs WebSocket API. For
> convenience, consider using [the official SDKs provided by ElevenLabs](/docs/eleven-agents/libraries/python).

The [ElevenAgents](https://elevenlabs.io/agents) WebSocket API enables real-time, interactive voice conversations with AI agents. By establishing a WebSocket connection, you can send audio input and receive audio responses in real-time, creating life-like conversational experiences.

> **Note**
>
> Endpoint: `wss://api.elevenlabs.io/v1/convai/conversation?agent_id={agent_id}`

## Authentication

### Using Agent ID

For public agents, you can directly use the `agent_id` in the WebSocket URL without additional authentication:

```bash
wss://api.elevenlabs.io/v1/convai/conversation?agent_id=<your-agent-id>
```

### Using a signed URL

For private agents or conversations requiring authorization, obtain a signed URL from your server, which securely communicates with the ElevenLabs API using your API key.

### Example using cURL

**Request:**

```bash
curl -X GET "https://api.elevenlabs.io/v1/convai/conversation/get-signed-url?agent_id=<your-agent-id>" \
     -H "xi-api-key: <your-api-key>"
```

**Response:**

```json
{
  "signed_url": "wss://api.elevenlabs.io/v1/convai/conversation?agent_id=<your-agent-id>&token=<token>"
}
```

> **Warning**
>
> Never expose your ElevenLabs API key on the client side.

## WebSocket events

### Client to server events

The following events can be sent from the client to the server:

#### Contextual Updates

Send non-interrupting contextual information to update the conversation state. This allows you to provide additional context without disrupting the ongoing conversation flow.

```javascript
{
  "type": "contextual_update",
  "text": "User clicked on pricing page"
}
```

**Use cases:**

* Updating user status or preferences
* Providing environmental context
* Adding background information
* Tracking user interface interactions

**Key points:**

* Does not interrupt current conversation flow
* Updates are incorporated as tool calls in conversation history
* Helps maintain context without breaking the natural dialogue

> **Note**
>
> Contextual updates are processed asynchronously and do not require a direct response from the server.

#### [WebSocket API Reference](/docs/eleven-agents/api-reference/eleven-agents/websocket)

See the ElevenLabs Agents WebSocket API reference documentation for detailed message structures,
parameters, and examples.

## Next.js implementation example

This example demonstrates how to implement a WebSocket-based conversational agent client in Next.js using the ElevenLabs WebSocket API.

> **Note**
>
> While this example uses the `voice-stream` package for microphone input handling, you can
> implement your own solution for capturing and encoding audio. The focus here is on demonstrating
> the WebSocket connection and event handling with the ElevenLabs API.

#### Install required dependencies

First, install the necessary packages:

```bash
npm install voice-stream
```

The `voice-stream` package handles microphone access and audio streaming, automatically encoding the audio in base64 format as required by the ElevenLabs API.

> **Note**
>
> This example uses Tailwind CSS for styling. To add Tailwind to your Next.js project:
>
> ```bash
> npm install -D tailwindcss postcss autoprefixer
> npx tailwindcss init -p
> ```
>
> Then follow the [official Tailwind CSS setup guide for Next.js](https://tailwindcss.com/docs/guides/nextjs).
>
> Alternatively, you can replace the className attributes with your own CSS styles.

#### Create WebSocket types

Define the types for WebSocket events:

**`app/types/websocket.ts`**

```typescript app/types/websocket.ts
type BaseEvent = {
  type: string;
};

type UserTranscriptEvent = BaseEvent & {
  type: "user_transcript";
  user_transcription_event: {
    user_transcript: string;
  };
};

type AgentResponseEvent = BaseEvent & {
  type: "agent_response";
  agent_response_event: {
    agent_response: string;
  };
};

type AgentResponseCorrectionEvent = BaseEvent & {
  type: "agent_response_correction";
  agent_response_correction_event: {
    original_agent_response: string;
    corrected_agent_response: string;
  };
};

type AudioResponseEvent = BaseEvent & {
  type: "audio";
  audio_event: {
    audio_base_64: string;
    event_id: number;
    alignment: {
      chars: string[];
      char_durations_ms: number[];
      char_start_times_ms: number[];
    };
  };
};

type InterruptionEvent = BaseEvent & {
  type: "interruption";
  interruption_event: {
    reason: string;
  };
};

type PingEvent = BaseEvent & {
  type: "ping";
  ping_event: {
    event_id: number;
    ping_ms?: number;
  };
};

type AgentChatResponsePartEvent = BaseEvent & {
  type: "agent_chat_response_part";
  text_response_part: {
    type: "start" | "delta" | "stop";
    text: string;
    event_id: number;
    response_id: string;
  };
};

export type ElevenLabsWebSocketEvent =
  | UserTranscriptEvent
  | AgentResponseEvent
  | AgentResponseCorrectionEvent
  | AudioResponseEvent
  | InterruptionEvent
  | PingEvent
  | AgentChatResponsePartEvent;
```

#### Create WebSocket hook

Create a custom hook to manage the WebSocket connection:

**`app/hooks/useAgentConversation.ts`**

```typescript app/hooks/useAgentConversation.ts
'use client';

import { useCallback, useEffect, useRef, useState } from 'react';
import { useVoiceStream } from 'voice-stream';
import type { ElevenLabsWebSocketEvent } from '../types/websocket';

const sendMessage = (websocket: WebSocket, request: object) => {
  if (websocket.readyState !== WebSocket.OPEN) {
    return;
  }
  websocket.send(JSON.stringify(request));
};

export const useAgentConversation = () => {
  const websocketRef = useRef<WebSocket>(null);
  const [isConnected, setIsConnected] = useState<boolean>(false);

  const { startStreaming, stopStreaming } = useVoiceStream({
    onAudioChunked: (audioData) => {
      if (!websocketRef.current) return;
      sendMessage(websocketRef.current, {
        user_audio_chunk: audioData,
      });
    },
  });

  const startConversation = useCallback(async () => {
    if (isConnected) return;

    const websocket = new WebSocket("wss://api.elevenlabs.io/v1/convai/conversation");

    websocket.onopen = async () => {
      setIsConnected(true);
      sendMessage(websocket, {
        type: "conversation_initiation_client_data",
      });
      await startStreaming();
    };

    websocket.onmessage = async (event) => {
      const data = JSON.parse(event.data) as ElevenLabsWebSocketEvent;

      // Handle ping events to keep connection alive
      if (data.type === "ping") {
        setTimeout(() => {
          sendMessage(websocket, {
            type: "pong",
            event_id: data.ping_event.event_id,
          });
        }, data.ping_event.ping_ms);
      }

      if (data.type === "user_transcript") {
        const { user_transcription_event } = data;
        console.log("User transcript", user_transcription_event.user_transcript);
      }

      if (data.type === "agent_response") {
        const { agent_response_event } = data;
        console.log("Agent response", agent_response_event.agent_response);
      }

      if (data.type === "agent_response_correction") {
        const { agent_response_correction_event } = data;
        console.log("Agent response correction", agent_response_correction_event.corrected_agent_response);
      }

      if (data.type === "interruption") {
        // Handle interruption
      }

      if (data.type === "audio") {
        const { audio_event } = data;
        // Implement your own audio playback system here
        // Note: You'll need to handle audio queuing to prevent overlapping
        // as the WebSocket sends audio events in chunks
      }

      if (data.type === "agent_chat_response_part") {
        const { text_response_part } = data;
        const { type: partType, text, response_id } = text_response_part;
        // Handle the agent's response text as it is generated. Enable
        // agent_chat_response_part in the agent's client_events to receive
        // this during voice conversations.
        console.log("Chat response part:", partType, text, response_id);
      }
    };

    websocketRef.current = websocket;

    websocket.onclose = async () => {
      websocketRef.current = null;
      setIsConnected(false);
      stopStreaming();
    };
  }, [startStreaming, isConnected, stopStreaming]);

  const stopConversation = useCallback(async () => {
    if (!websocketRef.current) return;
    websocketRef.current.close();
  }, []);

  useEffect(() => {
    return () => {
      if (websocketRef.current) {
        websocketRef.current.close();
      }
    };
  }, []);

  return {
    startConversation,
    stopConversation,
    isConnected,
  };
};
```

#### Create the conversation component

Create a component to use the WebSocket hook:

**`app/components/Conversation.tsx`**

```typescript app/components/Conversation.tsx
'use client';

import { useCallback } from 'react';
import { useAgentConversation } from '../hooks/useAgentConversation';

export function Conversation() {
  const { startConversation, stopConversation, isConnected } = useAgentConversation();

  const handleStart = useCallback(async () => {
    try {
      await navigator.mediaDevices.getUserMedia({ audio: true });
      await startConversation();
    } catch (error) {
      console.error('Failed to start conversation:', error);
    }
  }, [startConversation]);

  return (
    <div className="flex flex-col items-center gap-4">
      <div className="flex gap-2">
        <button
          onClick={handleStart}
          disabled={isConnected}
          className="px-4 py-2 bg-blue-500 text-white rounded disabled:bg-gray-300"
        >
          Start Conversation
        </button>
        <button
          onClick={stopConversation}
          disabled={!isConnected}
          className="px-4 py-2 bg-red-500 text-white rounded disabled:bg-gray-300"
        >
          Stop Conversation
        </button>
      </div>
      <div className="flex flex-col items-center">
        <p>Status: {isConnected ? 'Connected' : 'Disconnected'}</p>
      </div>
    </div>
  );
}
```

## Next steps

1. **Audio Playback**: Implement your own audio playback system using Web Audio API or a library. Remember to handle audio queuing to prevent overlapping as the WebSocket sends audio events in chunks.
2. **Error Handling**: Add retry logic and error recovery mechanisms
3. **UI Feedback**: Add visual indicators for voice activity and connection status

## Latency management

To ensure smooth conversations, implement these strategies:

* **Adaptive Buffering:** Adjust audio buffering based on network conditions.
* **Jitter Buffer:** Implement a jitter buffer to smooth out variations in packet arrival times.
* **Ping-Pong Monitoring:** Use ping and pong events to measure round-trip time and adjust accordingly.

## Security best practices

* Rotate API keys regularly and use environment variables to store them.
* Implement rate limiting to prevent abuse.
* Clearly explain the intention when prompting users for microphone access.
* Optimized Chunking: Tweak the audio chunk duration to balance latency and efficiency.

## Additional resources

* [ElevenLabs Agents Documentation](/docs/eleven-agents/overview)
* [ElevenLabs Agents SDKs](/docs/eleven-agents/libraries/python)

> ElevenLabs provides APIs and SDKs for text to speech, voice cloning, speech to text, sound effects, voice isolator, voice changer, and conversational AI agents. Build voice-enabled applications with lifelike audio generation.