Inworld

Inworld AI

Text-to-Speech platform with voice cloning, audio markups, and timestamp alignment.

Quick Navigation

| Topic | Reference | | ------------- | ----------------------------------------------- | | Installation | [installation.md](references/installation.md) | | Voice Cloning | [cloning.md](references/cloning.md) | | Voice Control | [voice-control.md](references/voice-control.md) | | API Reference | [api.md](references/api.md) |

When to Use

• Text-to-speech audio generation
• Voice cloning from 5-15 seconds of audio
• Emotion-controlled speech ([happy], [sad], etc.)
• Word/phoneme timestamps for lip sync
• Custom pronunciation with IPA

Models

| Model | ID | Latency | Price | | ------------ | ---------------------- | ------- | ----------- | | TTS-2 | inworld-tts-2 | latest | see pricing | | TTS 1.5 Max | inworld-tts-1.5-max | legacy | legacy | | TTS 1.5 Mini | inworld-tts-1.5-mini | legacy | legacy |

Minimal Example

import requests, base64, os

response = requests.post(
    "https://api.inworld.ai/tts/v1/voice",
    headers={"Authorization": f"Basic {os.getenv('INWORLD_API_KEY')}"},
    json={"text": "Hello!", "voiceId": "Ashley", "modelId": "inworld-tts-1.5-max"}
)
audio = base64.b64decode(response.json()['audioContent'])

Key Features

• 15 languages — en, zh, ja, ko, ru, it, es, pt, fr, de, pl, nl, hi, he, ar
• Instant cloning — 5-15 seconds audio, no training
• Audio markups — [happy], [laughing], [sigh] (English only)
• Timestamps — word, phoneme, viseme timing for lip sync
• Streaming — /voice:stream endpoint
• TTS-2 steering — natural-language bracketed directions such as [say excitedly] or [whisper in a hushed style]
• Delivery mode — STABLE, BALANCED, CREATIVE trade consistency for emotional range
• Cross-lingual synthesis — reuse one voice across multiple languages; voice localization improves native-sounding output

Release Highlights (TTS-2)

• Realtime TTS-2 becomes the new primary model line via modelId="inworld-tts-2".
• Steering moves beyond the older fixed emotion tags: free-form bracketed directions can control style, pitch, speed, intensity, and non-verbals.
• Multilingual coverage expands with production quality across 15 languages and broader experimental coverage beyond that.
• deliveryMode adds a stability-vs-creativity knob, and specifying language matters more for cross-lingual output quality.

Prohibitions

• Audio markups work only in English
• Use ONE emotion markup at text beginning
• Match voice language to text language
• Instant cloning may not work for children's voices or unique accents

Links

• Documentation
• Changelog
• Platform

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: itechmeat
• Source: itechmeat/llm-code
• License: MIT

Install and usage instructions live in the source repository linked above.