> ## Documentation Index
> Fetch the complete documentation index at: https://hanabiaiinc-him188-rename-multi-turn-simulation.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# WebSocket TTS with Timestamps

> Stream text and receive speech with word-level timestamps over WebSocket

<Note>
  Connect to `wss://api.fish.audio/v1/tts/live/with-timestamp` with a WebSocket
  client. The endpoint requires a WebSocket upgrade and returns MessagePack
  binary frames. A normal HTTP GET request does not start synthesis.
</Note>

## Before you start

You need a [Fish Audio API key](/developer-guide/getting-started/api-key) and a
WebSocket client that supports custom authentication headers. To run the Python
example on this page, install its dependencies:

```bash theme={null}
pip install ormsgpack websockets
```

Replace `<token>` in the example with your API key and set `reference_id` to your
voice model ID. The `start.request` object accepts the same parameters as the
[Text to Speech API](/api-reference/endpoint/openapi-v1/text-to-speech).
Send text and receive audio concurrently, then keep reading after sending `stop`
until the server sends `finish`.

## Preserve the final timestamps

Process alignment metadata even when an `audio` event contains empty audio bytes:
a trailing event can carry a final alignment correction. Store each non-null
`alignment` by `chunk_seq`, replacing its previous snapshot. A null alignment
does not erase a snapshot you already received.

Add `chunk_audio_offset_sec` to each segment's `start` and `end` to place it on
the session's audio timeline. The optional `time` field measures elapsed server
session time in milliseconds; use the segment timestamps for captions.

After `finish`, you can send another `start` on the same socket. Reset your audio
buffer and stored alignment snapshots for the new session.

## Related endpoints

* [Text to Speech Stream with Timestamps](/api-reference/endpoint/openapi-v1/text-to-speech-stream-with-timestamps): send the full text in one HTTP request and receive audio and timestamps over SSE.
* [WebSocket TTS Streaming](/api-reference/endpoint/websocket/tts-live): stream text and audio without timestamps.