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

# Telnyx STT

> Streaming speech-to-text bundled with your Telnyx telephony plan — single bill, on-network audio.

# Telnyx STT

`TelnyxSTT` is a streaming speech-to-text provider that talks to Telnyx's `wss://api.telnyx.com/v2/speech-to-text/transcription` endpoint. It implements the same callback-based contract as the other Patter STT adapters ([`DeepgramSTT`](/typescript-sdk/providers/deepgram), [`AssemblyAISTT`](/typescript-sdk/providers/assemblyai)) — drop it into pipeline mode wherever those would go.

## Why use it

If you're already on Telnyx for telephony (see [Carrier — Telnyx](/typescript-sdk/carrier#telnyx)), you can keep STT on the same vendor:

* **One bill, one credential.** No extra Deepgram / AssemblyAI / Speechmatics account to manage.
* **On-network audio path.** Caller audio arrives at Telnyx's edge for the carrier hop; routing it to Telnyx STT from the same edge keeps the audio inside their backbone instead of egressing to a third-party STT.
* **Pluggable backend.** Telnyx fronts four transcription engines (`telnyx`, `google`, `deepgram`, `azure`) behind a single API — pick whichever quality / language profile suits the call without changing wire protocol.

## Install

`TelnyxSTT` ships in the core `getpatter` package — no extras needed:

```bash theme={null}
npm install getpatter
```

## Quickstart

<CodeGroup>
  ```typescript TypeScript theme={null}
  // npx tsx example.ts
  import { Patter, Telnyx, ElevenLabsTTS } from "getpatter";
  import { TelnyxSTT } from "getpatter/dist/providers/telnyx-stt";

  const phone = new Patter({ carrier: new Telnyx(), phoneNumber: "+15550001234" });

  const agent = phone.agent({
    stt: new TelnyxSTT(process.env.TELNYX_API_KEY!, "en"),
    tts: ElevenLabsTTS.forTelnyx({}),                     // ELEVENLABS_API_KEY from env
    systemPrompt: "You are a helpful assistant.",
  });

  await phone.serve({ agent });
  ```

  ```python Python theme={null}
  import asyncio
  from getpatter import Patter, Telnyx, ElevenLabsTTS
  from getpatter.providers.telnyx_stt import TelnyxSTT

  phone = Patter(carrier=Telnyx(), phone_number="+15550001234")

  agent = phone.agent(
      stt=TelnyxSTT(api_key="KEY...", language="en"),
      tts=ElevenLabsTTS.for_telnyx(),
      system_prompt="You are a helpful assistant.",
  )

  asyncio.run(phone.serve(agent))
  ```
</CodeGroup>

## Constructor

```typescript theme={null}
new TelnyxSTT(
  apiKey: string,
  language: string = "en",
  transcriptionEngine: TelnyxTranscriptionEngine = "telnyx",
  sampleRate: number = 16000,
  baseUrl: string = "wss://api.telnyx.com/v2/speech-to-text/transcription",
)

type TelnyxTranscriptionEngine = "telnyx" | "google" | "deepgram" | "azure";
```

| Parameter             | Default         | Description                                                                               |
| --------------------- | --------------- | ----------------------------------------------------------------------------------------- |
| `apiKey`              | — required      | Telnyx API v2 key (Bearer token).                                                         |
| `language`            | `"en"`          | ISO 639-1 language code (e.g. `"en"`, `"es"`, `"fr"`).                                    |
| `transcriptionEngine` | `"telnyx"`      | Backend engine. One of `"telnyx"`, `"google"`, `"deepgram"`, `"azure"`.                   |
| `sampleRate`          | `16000`         | PCM input sample rate in Hz. The adapter sends a streaming WAV header on the first chunk. |
| `baseUrl`             | Telnyx prod URL | Override for testing.                                                                     |

## Sample rates

| Sample rate       | Use case                                             |
| ----------------- | ---------------------------------------------------- |
| `8000`            | Match Twilio Media Streams μ-law without resampling. |
| `16000` (default) | Telnyx default media-streaming format (L16 PCM).     |
| `24000`           | Higher-fidelity inputs (e.g. browser RTC).           |

## Pricing

Telnyx STT pricing varies by transcription engine and is bundled with your Telnyx plan — see the [Telnyx STT pricing page](https://telnyx.com/pricing/speech-to-text). Patter does not charge an STT line item for `TelnyxSTT`; the cost shows up on your Telnyx invoice alongside the carrier minutes. See [Metrics](/typescript-sdk/metrics) for how to register a custom rate via the `pricing` option on `new Patter({...})` if you want it surfaced in the dashboard.

## Low-level usage

```typescript theme={null}
import { TelnyxSTT } from "getpatter/dist/providers/telnyx-stt";

const stt = new TelnyxSTT(process.env.TELNYX_API_KEY!, "en", "deepgram");
await stt.connect();

stt.onTranscript((t) => {
  console.log(t.text, t.isFinal, t.confidence);
});

stt.sendAudio(pcm16Buffer);                 // 16 kHz PCM s16le mono
// ... at end of call:
stt.close();
```

Up to 10 concurrent `onTranscript` listeners are accepted.

## See also

* [STT overview](/typescript-sdk/stt) — provider table and shared concepts.
* [Carrier — Telnyx](/typescript-sdk/carrier#telnyx) — picking Telnyx as your telephony provider.
* [Telnyx TTS](/typescript-sdk/providers/telnyx-tts) — pair this STT with carrier-bundled TTS.