# Deepgram Aura-2 Text to Speech

> Deepgram Aura-2 Text to Speech is a paid API for AI agents from Deepgram at deepgram.mpp.paywithlocus.com, paid per call via MPP, $0.023/call, not verified (last probed 2026-10-12); live alternatives: x402engine ElevenLabs Text-to-Speech ($0.02) and Google Gemini 3.1 Flash TTS ($0.0028).

Agents call it through Zero, which pays per call: no API key and no wallet of your own. New accounts start with $5.

Live alternatives for the same use case:
- [x402engine ElevenLabs Text-to-Speech](https://www.zero.xyz/c/x402engine-elevenlabs-text-to-speech-6db68b62) ($0.02)
- [Google Gemini 3.1 Flash TTS](https://www.zero.xyz/c/audio-withzero-xyz-google-gemini-3-1-flash-tts-text-to-speech-f794324b) ($0.0028)

Converts text to natural-sounding speech audio using Deepgram's Aura-2 TTS voice models

## Facts

- Endpoint: POST https://deepgram.mpp.paywithlocus.com/deepgram/speak?utm_source=zero.xyz
- Price: $0.023/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-12
- Last successful call: 2026-07-02
- Success rate: 47% of calls made through Zero
- Rating: 4.8 / 5 from 2 reviews
- Activations on Zero: 18
- Provider: Deepgram
- Docs: https://developers.deepgram.com/reference/deepgram-api-overview
- Website: https://deepgram.com
- Tags: speech-to-text, transcription, tts, audio, sentiment, data
- Canonical page: https://www.zero.xyz/c/deepgram-speak-08651d8a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_V5L75fH3vGK4Q2EE4Ifo_

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability deepgram-speak-08651d8a -d '<json body>'
```

Example prompt: Read the following text aloud using Deepgram's Aura-2 Thalia voice and save it as an mp3: 'Welcome to our platform. We're glad you're here and hope you enjoy the experience.'

## When to prefer this

Choose this endpoint when you need high-quality AI-generated speech audio powered by Deepgram's Aura-2 voice models, especially when you're already using Deepgram's ecosystem (transcription, analysis). Prefer this over generic TTS if you want Deepgram's specific Aura voice lineup, flexible audio encoding options (mp3, flac, opus, aac, mulaw), or need to pay per-call via USDC on a decentralized facilitator network.

## Known failure modes

- Text exceeds recommended ~2000 character limit — may result in truncation or error
- Invalid voice model name format — must follow aura-2-{voice}-{lang} pattern
- Unsupported encoding/container combination — returns 400 error
- Empty or missing text field — returns validation error
- Network timeout for very long texts
- Unsupported sample_rate value — returns 400 error

## How this service works

Convert text to natural-sounding speech using Deepgram Aura-2 voices. Returns base64-encoded audio (MP3 by default). Choose from 46+ English voices and voices in Spanish, French, German, Dutch, Italian, and Japanese.

## Output

Returns a binary audio file (default mp3) containing the synthesized speech. The response is a raw audio stream, typically tens of kilobytes to hundreds of kilobytes depending on text length. The original response example showed ~36KB for a short sentence.

## Example request

```json
{
 "text": "Hello, this is a test of the text to speech service. The weather is nice today."
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "text"
 ],
 "properties": {
  "text": {
   "type": "string",
   "description": "Text to convert to speech. Max ~2000 chars recommended per call."
  },
  "model": {
   "type": "string",
   "description": "TTS voice model (default: aura-2-thalia-en). Format: aura-2-{voice}-{lang}. E.g. aura-2-apollo-en, aura-2-thalia-en, aura-2-orion-en"
  },
  "encoding": {
   "type": "string",
   "description": "Audio encoding (default: mp3). Options: mp3, linear16, flac, mulaw, alaw, opus, aac"
  },
  "container": {
   "type": "string",
   "description": "Audio container format. Options: mp3, wav, ogg, none"
  },
  "sample_rate": {
   "type": "string",
   "description": "Output sample rate in Hz (e.g. 24000, 16000, 8000)"
  }
 },
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/deepgram-speak-08651d8a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from deepgram.mpp.paywithlocus.com](https://www.zero.xyz/host/deepgram.mpp.paywithlocus.com/llms.txt)