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

# Speech-to-Text REST API overview

> Transcribe audio files synchronously with the Telnyx Speech-to-Text REST API by uploading a file or providing a public URL and receiving text.

`POST /v2/ai/audio/transcriptions`

Synchronous file transcription. Upload audio or pass a URL, get text back.

## Feature Support

If you're coming from alternative providers:

| Feature                  | Status                                                                                                                                                 |
| ------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------ |
| OpenAI SDK compatible    | **Yes** — swap `base_url` and `api_key`, existing code works                                                                                           |
| Multi-engine selection   | **Yes** — 3 models behind one endpoint                                                                                                                 |
| File upload              | **Yes**                                                                                                                                                |
| URL transcription        | **Yes** (`file_url`)                                                                                                                                   |
| Timestamps (segment)     | **Yes** (`verbose_json`)                                                                                                                               |
| Timestamps (word-level)  | **Deepgram only** (via `model_config`)                                                                                                                 |
| Diarization              | **Deepgram only** (via `model_config`)                                                                                                                 |
| Smart formatting         | **Deepgram only** (via `model_config`)                                                                                                                 |
| Multilingual             | **Model-dependent** — whisper-turbo: 80+ languages, whisper-tiny: 50+ languages, Deepgram models support language coverage based on the selected model |
| Async / webhooks         | No                                                                                                                                                     |
| Multichannel             | No (forced mono)                                                                                                                                       |
| Export formats (SRT/VTT) | No                                                                                                                                                     |
| Audio event tagging      | No                                                                                                                                                     |
| YouTube/TikTok URL       | No                                                                                                                                                     |
| Transcript retrieval     | No                                                                                                                                                     |
| File size limit          | 100 MB                                                                                                                                                 |

## Quick Start

<CodeGroup>
  ```python Python theme={null}
  from openai import OpenAI

  client = OpenAI(
      api_key="YOUR_TELNYX_API_KEY",
      base_url="https://api.telnyx.com/v2",
  )

  result = client.audio.transcriptions.create(
      model="openai/whisper-large-v3-turbo",
      file=open("audio.mp3", "rb"),
  )
  ```

  ```javascript JavaScript theme={null}
  import OpenAI from "openai";
  import fs from "fs";

  const client = new OpenAI({
    apiKey: "YOUR_TELNYX_API_KEY",
    baseURL: "https://api.telnyx.com/v2",
  });

  const result = await client.audio.transcriptions.create({
    model: "openai/whisper-large-v3-turbo",
    file: fs.createReadStream("audio.mp3"),
  });
  ```
</CodeGroup>