Inworld TTS Provider for OpenClaw

Inworld is a streaming text-to-speech (TTS) provider. OpenClaw uses it to generate outbound reply audio (MP3 by default, OGG_OPUS for voice notes) and raw PCM audio for telephony channels like Voice Call.

OpenClaw sends requests to Inworld's streaming TTS endpoint, concatenates the returned base64 audio chunks into one buffer, and passes the result to the standard reply-audio pipeline.

Property	Value
Provider id	`inworld`
Plugin	official external package (`@openclaw/inworld-speech`)
Contract	`speechProviders` (TTS only)
Auth env var	`INWORLD_API_KEY` (HTTP Basic, Base64 dashboard credential)
Base URL	`https://api.inworld.ai`
Default voice	`Sarah`
Default model	`inworld-tts-1.5-max`
Output	MP3 (default), OGG_OPUS (voice notes), PCM 22050 Hz (telephony)
Website	inworld.ai
Docs	docs.inworld.ai/tts/tts

Install plugin

openclaw plugins install @openclaw/inworld-speech
openclaw gateway restart

Getting started

Set your API key

Get the credential from your Inworld dashboard (Workspace > API Keys) and set it as an environment variable. The value is sent exactly as the HTTP Basic credential, so do not Base64-encode it again or convert it to a bearer token.

INWORLD_API_KEY=<base64-credential-from-dashboard>

Select Inworld in tts

{
  tts: {
    auto: "always",
    provider: "inworld",
    providers: {
      inworld: {
        voiceId: "Sarah",
        modelId: "inworld-tts-1.5-max",
      },
    },
  },
}

Send a message

Send a reply through any connected channel. OpenClaw synthesizes the audio with Inworld and delivers it as MP3 (or OGG_OPUS when the channel expects a voice note).

Configuration options

Option	Path	Description
`apiKey`	`tts.providers.inworld.apiKey`	Base64 dashboard credential. Falls back to `INWORLD_API_KEY`.
`baseUrl`	`tts.providers.inworld.baseUrl`	Override Inworld API base URL (default `https://api.inworld.ai`).
`voiceId`	`tts.providers.inworld.voiceId`	Voice identifier (default `Sarah`). Legacy alias: `speakerVoiceId`.
`modelId`	`tts.providers.inworld.modelId`	TTS model id (default `inworld-tts-1.5-max`).
`temperature`	`tts.providers.inworld.temperature`	Sampling temperature, `0` (exclusive) to `2` (optional).

Notes

Authentication

Inworld uses HTTP Basic auth with a single Base64-encoded credential string. Copy it directly from the Inworld dashboard. The provider sends it as Authorization: Basic <apiKey> without any additional encoding, so do not Base64-encode it yourself and do not pass a bearer-style token. See TTS auth notes for the same callout.

Models

Supported model ids: inworld-tts-1.5-max (default), inworld-tts-1.5-mini, inworld-tts-1-max, inworld-tts-1.

Audio outputs

Replies use MP3 by default. When the channel target is voice-note, OpenClaw requests OGG_OPUS from Inworld so the audio plays as a native voice bubble. Telephony synthesis uses raw PCM at 22050 Hz to feed the telephony bridge.

Custom endpoints

Override the API host with tts.providers.inworld.baseUrl. Trailing slashes are removed before requests are sent.

Text-to-speech, TTS overview, providers, and tts config.
Configuration, Full config reference including tts settings.
Providers, All supported OpenClaw providers.
Troubleshooting, Common issues and debugging steps.