Inworld is a streaming text-to-speech (TTS) provider. In OpenClaw it
synthesizes outbound reply audio (MP3 by default, OGG_OPUS for voice notes)
and PCM audio for telephony channels such as Voice Call.
OpenClaw posts to Inworld's streaming TTS endpoint, concatenates the
returned base64 audio chunks into a single buffer, and hands the result to
the standard reply-audio pipeline.
| Property | Value |
|---|
| Provider id | inworld |
| Plugin | bundled, enabledByDefault: true |
| 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 |
Getting started
Copy the credential from your Inworld dashboard (Workspace > API Keys)
and set it as an env var. The value is sent verbatim 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>
```
```json5
{
messages: {
tts: {
auto: "always",
provider: "inworld",
providers: {
inworld: {
voiceId: "Sarah",
modelId: "inworld-tts-1.5-max",
},
},
},
},
}
```
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 | messages.tts.providers.inworld.apiKey | Base64 dashboard credential. Falls back to INWORLD_API_KEY. |
baseUrl | messages.tts.providers.inworld.baseUrl | Override Inworld API base URL (default https://api.inworld.ai). |
voiceId | messages.tts.providers.inworld.voiceId | Voice identifier (default Sarah). |
modelId | messages.tts.providers.inworld.modelId | TTS model id (default inworld-tts-1.5-max). |
temperature | messages.tts.providers.inworld.temperature | Sampling temperature 0..2 (optional). |
Notes
Inworld uses HTTP Basic auth with a single Base64-encoded credential
string. Copy it verbatim from the Inworld dashboard. The provider sends
it as `Authorization: Basic ` without any further encoding, so
do not Base64-encode it yourself and do not pass a bearer-style token.
See [TTS auth notes](/docs/openclaw-docs/tools/tts#inworld-primary for the same callout.
Supported model ids: `inworld-tts-1.5-max` (default),
`inworld-tts-1.5-mini`, `inworld-tts-1-max`, `inworld-tts-1`.
Replies use MP3 by default. When the channel target is `voice-note`
OpenClaw asks Inworld for `OGG_OPUS` so the audio plays as a native
voice bubble. Telephony synthesis uses raw `PCM` at 22050 Hz to feed
the telephony bridge.
Override the API host with `messages.tts.providers.inworld.baseUrl`.
Trailing slashes are stripped before requests are sent.
TTS overview, providers, and `messages.tts` config.
Full config reference including `messages.tts` settings.
All bundled OpenClaw providers.
Common issues and debugging steps.