Inworld TTS 1.5 Mini

Text-to-Speech • Inworld

inworld/tts-1.5-mini

• Third-party
• Zero data retention

Ultra-fast, cost-efficient text-to-speech with approximately 120ms latency and 15-language support.

Usage

const response = await env.AI.run(
  'inworld/tts-1.5-mini',
  {
    output_format: 'mp3',
    temperature: 1,
    text: 'Hello! Welcome to Cloudflare AI Gateway. Let me show you what we can do.',
    timestamp_type: 'none',
    voice_id: 'Dennis',
  },
)
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": "inworld/tts-1.5-mini",
  "input": {
    "output_format": "mp3",
    "temperature": 1,
    "text": "Hello! Welcome to Cloudflare AI Gateway. Let me show you what we can do.",
    "timestamp_type": "none",
    "voice_id": "Dennis"
  }
}'

{
  "gatewayMetadata": {
    "keySource": "Unified"
  },
  "result": {
    "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/inworld__tts-1.5-mini/simple-speech.mp3"
  },
  "state": "Completed"
}

Examples

<details>

<summary>Fast Speech — Speed up speech for quick playback</summary>

const response = await env.AI.run(
  'inworld/tts-1.5-mini',
  {
    output_format: 'mp3',
    speaking_rate: 1.4,
    temperature: 1,
    text: 'This is a fast-paced summary of the key findings from the quarterly report. Revenue is up fifteen percent and user growth exceeded expectations.',
    timestamp_type: 'none',
    voice_id: 'Dennis',
  },
)
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": "inworld/tts-1.5-mini",
  "input": {
    "output_format": "mp3",
    "speaking_rate": 1.4,
    "temperature": 1,
    "text": "This is a fast-paced summary of the key findings from the quarterly report. Revenue is up fifteen percent and user growth exceeded expectations.",
    "timestamp_type": "none",
    "voice_id": "Dennis"
  }
}'

{
  "gatewayMetadata": {
    "keySource": "Unified"
  },
  "result": {
    "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/inworld__tts-1.5-mini/fast-speech.mp3"
  },
  "state": "Completed"
}

</details>

<details>

<summary>Low Latency — Minimize latency by disabling text normalization</summary>

const response = await env.AI.run(
  'inworld/tts-1.5-mini',
  {
    apply_text_normalization: false,
    output_format: 'mp3',
    temperature: 1,
    text: 'Quick response needed. The server is ready.',
    timestamp_type: 'none',
    voice_id: 'Dennis',
  },
)
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": "inworld/tts-1.5-mini",
  "input": {
    "apply_text_normalization": false,
    "output_format": "mp3",
    "temperature": 1,
    "text": "Quick response needed. The server is ready.",
    "timestamp_type": "none",
    "voice_id": "Dennis"
  }
}'

{
  "gatewayMetadata": {
    "keySource": "Unified"
  },
  "result": {
    "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/inworld__tts-1.5-mini/low-latency.mp3"
  },
  "state": "Completed"
}

</details>

Parameters

text

stringrequiredmaxLength: 2000The text to be synthesized into speech. Maximum input of 2,000 characters.

voice_id

stringrequireddefault: Dennisenum: Loretta, Darlene, Marlene, Hank, Evelyn, Celeste, Pippa, Tessa, Liam, Callum, Hamish, Abby, Graham, Rupert, Mortimer, Snik, Anjali, Saanvi, Arjun, Claire, Oliver, Simon, Elliot, James, Serena, Gareth, Vinny, Lauren, Jessica, Ethan, Tyler, Jason, Chloe, Veronica, Victoria, Miranda, Sebastian, Victor, Malcolm, Nate, Brian, Amina, Kelsey, Derek, Evan, Kayla, Jake, Grant, Tristan, Nadia, Selene, Marcus, Riley, Damon, Cedric, Mia, Naomi, Jonah, Levi, Avery, Brandon, Conrad, Bianca, Lucian, Trevor, Alex, Ashley, Craig, Deborah, Dennis, Edward, Elizabeth, Hades, Julia, Pixie, Mark, Olivia, Priya, Ronald, Sarah, Shaun, Theodore, Timothy, Wendy, Dominus, Hana, Clive, Carter, Blake, Luna, Reed, Duncan, Felix, Eleanor, SophieThe ID of the voice to use for synthesizing speech. Defaults to Dennis.

output_format

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

bit_rate

integerminimum: -9007199254740991maximum: 9007199254740991Bits per second of the audio. Only for compressed audio formats (mp3, opus). The default is 128,000.

sample_rate

integerminimum: -9007199254740991maximum: 9007199254740991The synthesis sample rate in hertz. Accepts: 8000, 16000, 22050, 24000, 32000, 44100, 48000. The default is 48,000.

speaking_rate

numberminimum: 0.5maximum: 1.5Speaking rate/speed, in the range [0.5, 1.5]. The default is 1.0. We recommend using values above 0.8 to ensure high quality.

temperature

numberrequireddefault: 1minimum: 0.01maximum: 2Determines the degree of randomness when sampling audio tokens. Defaults to 1.0. Accepts values between 0 (exclusive) and 2 (inclusive). Higher values = more expressive, lower values = more deterministic.

timestamp_type

stringrequireddefault: noneenum: none, word, characterControls timestamp metadata returned with the audio. "word" returns word-level timing, "character" returns character-level timing. Note: adds latency. Defaults to none.

apply_text_normalization

booleanWhen enabled, text normalization expands numbers, dates, times, and abbreviations before converting to speech. Turning this off may reduce latency.

audio

stringURL to the generated audio file

API Schemas (Raw)

Input Open Download

Output Open Download

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Docs

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description: Inworld's most powerful and expressive text-to-speech model. Builds on TTS 1.5 with rich expressive speech, real-time latency, natural language steering (e.g. [whisper], [say excitedly]), and stronger multilingual support across 15 production languages plus 90+ experimental languages. title: Inworld TTS 2 image: https://developers.cloudflare.com/og-docs.png

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