TTS-1

Model ID

Use with the Workers AI binding, the AI Gateway REST API, or the Unified API.

Calling the provider directly? Use the provider's model name instead, including with provider-native endpoints or the provider's own SDK. For example, Anthropic's name for anthropic/claude-opus-4.8 is claude-opus-4-8.

Third-party
Zero data retention

OpenAI's text-to-speech model optimized for real-time use with low latency.

Model Info
Terms and License	link ↗
More information	link ↗
Zero data retention	Yes
Pricing	Per character$0.000015

Usage

const response = await env.AI.run(
  'openai/tts-1',
  {
    response_format: 'mp3',
    speed: 1,
    text: 'Hello! Welcome to Cloudflare AI Gateway. Let me show you what we can do.',
    voice: 'alloy',
  },
)
console.log(response)

curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \
  --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
  --header "Content-Type: application/json" \
  --data '{
  "model": "openai/tts-1",
  "input": {
    "response_format": "mp3",
    "speed": 1,
    "text": "Hello! Welcome to Cloudflare AI Gateway. Let me show you what we can do.",
    "voice": "alloy"
  }
}'

{
  "gatewayMetadata": {
    "keySource": "Unified"
  },
  "result": {
    "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/openai__tts-1/simple-speech.mp3"
  },
  "state": "Completed"
}

Examples

Different Voice — Use the Nova voice for a different tone

const response = await env.AI.run(
  'openai/tts-1',
  {
    response_format: 'mp3',
    speed: 1,
    text: 'The weather today is sunny with a high of 72 degrees. Perfect for a walk in the park.',
    voice: 'nova',
  },
)
console.log(response)

curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \
  --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
  --header "Content-Type: application/json" \
  --data '{
  "model": "openai/tts-1",
  "input": {
    "response_format": "mp3",
    "speed": 1,
    "text": "The weather today is sunny with a high of 72 degrees. Perfect for a walk in the park.",
    "voice": "nova"
  }
}'

{
  "gatewayMetadata": {
    "keySource": "Unified"
  },
  "result": {
    "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/openai__tts-1/different-voice.mp3"
  },
  "state": "Completed"
}

Narration — Slower narration style with the Onyx voice

const response = await env.AI.run(
  'openai/tts-1',
  {
    response_format: 'mp3',
    speed: 0.85,
    text: 'In the beginning, the universe was a singularity of infinite density. Then, in a fraction of a second, it expanded into everything we know today.',
    voice: 'onyx',
  },
)
console.log(response)

curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \
  --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
  --header "Content-Type: application/json" \
  --data '{
  "model": "openai/tts-1",
  "input": {
    "response_format": "mp3",
    "speed": 0.85,
    "text": "In the beginning, the universe was a singularity of infinite density. Then, in a fraction of a second, it expanded into everything we know today.",
    "voice": "onyx"
  }
}'

{
  "gatewayMetadata": {
    "keySource": "Unified"
  },
  "result": {
    "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/openai__tts-1/narration.mp3"
  },
  "state": "Completed"
}

Echo Voice — Use the Echo voice for a deeper tone

const response = await env.AI.run(
  'openai/tts-1',
  {
    response_format: 'mp3',
    speed: 1,
    text: 'Welcome back to the podcast. Today we are going to talk about the future of artificial intelligence and its impact on creative work.',
    voice: 'echo',
  },
)
console.log(response)

curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \
  --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
  --header "Content-Type: application/json" \
  --data '{
  "model": "openai/tts-1",
  "input": {
    "response_format": "mp3",
    "speed": 1,
    "text": "Welcome back to the podcast. Today we are going to talk about the future of artificial intelligence and its impact on creative work.",
    "voice": "echo"
  }
}'

{
  "gatewayMetadata": {
    "keySource": "Unified"
  },
  "result": {
    "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/openai__tts-1/echo-voice.mp3"
  },
  "state": "Completed"
}

Fast Playback — Speed up speech for quick listening

const response = await env.AI.run(
  'openai/tts-1',
  {
    response_format: 'mp3',
    speed: 1.5,
    text: 'This is a fast-paced summary of the key findings from the quarterly report. Revenue is up fifteen percent, user growth exceeded expectations, and infrastructure costs remain stable.',
    voice: 'shimmer',
  },
)
console.log(response)

curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \
  --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
  --header "Content-Type: application/json" \
  --data '{
  "model": "openai/tts-1",
  "input": {
    "response_format": "mp3",
    "speed": 1.5,
    "text": "This is a fast-paced summary of the key findings from the quarterly report. Revenue is up fifteen percent, user growth exceeded expectations, and infrastructure costs remain stable.",
    "voice": "shimmer"
  }
}'

{
  "gatewayMetadata": {
    "keySource": "Unified"
  },
  "result": {
    "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/openai__tts-1/fast-playback.mp3"
  },
  "state": "Completed"
}

Parameters

text

stringrequiredmaxLength: 4096The text to generate audio for. Maximum length is 4096 characters.

voice

stringrequireddefault: alloyenum: alloy, echo, fable, onyx, nova, shimmerThe voice to use when generating the audio. Defaults to alloy.

response_format

stringrequireddefault: mp3enum: mp3, opus, wav, aac, flacThe output format for the audio. Supported formats are mp3, opus, wav, aac and flac.

speed

numberrequireddefault: 1minimum: 0.25maximum: 4The speed of the generated audio. Select a value from 0.25 to 4.0. 1.0 is the default.

audio

stringURL to the generated audio file

API Schemas (Raw)

Input

Output