# Inworld Realtime API (slim)

> Inworld's Realtime API runs spoken conversations over WebSocket or WebRTC, chaining Inworld STT, an LLM chosen by the developer and Inworld TTS, with turn detection, interruptions and tool calling. It follows OpenAI's Realtime protocol.

- Full: https://www.anchorterminal.com/tools/inworld-realtime.md (~7,400 tokens) · this version ~1,430 tokens · JSON https://www.anchorterminal.com/tools/inworld-realtime.json · canonical https://www.anchorterminal.com/tools/inworld-realtime
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-07 · pricing https://www.anchorterminal.com/tools/inworld-realtime#pricing · reviews https://www.anchorterminal.com/tools/inworld-realtime#reviews
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

**C · 60.1/100 · rank #668 of 1486 · #12 in Conversational voice agents · not agent-ready · confidence medium**


Assessment: Inworld's Realtime API speaks OpenAI's Realtime protocol over WebSocket or WebRTC, with a choice of LLM, client-side tools and dated release notes. Cost is the sum of STT, LLM and TTS usage with no per-minute price, there is no machine-readable event schema, and status history couldn't be read.

## Facts

- Kind: HTTP API · vendor: Inworld AI · category: Conversational voice agents · legal entity: Theai, Inc. dba Inworld AI · provenance 75/100
- Local only (websocket, HTTP): npm `@inworld/cli`
- Auth: API key · pricing: Pay per use · x402: no · licence: unknown
- Benchmark probes: not run yet, so Performance is pending
- Vendor status page: not read, no machine-readable status found (2026-11-07 04:47 UTC)
- Surface listed: The Realtime API at api.inworld.ai, read from docs.inworld.ai (llms.txt, Markdown guides, the WebSocket and WebRTC reference, Realtime release notes) and inworld.ai/pricing on 6 November 2026, with terms, privacy, security and status as read for inworld-tts on 4 November. No account was made and no session was opened
- Architecture: A pipeline, not a single speech-to-speech model. STT (`inworld/inworld-stt-1` by default), an LLM the developer picks through Inworld's router, and Inworld TTS, each billed as its own line
- Session controls: Semantic and server VAD, interruptions, client-side tool calling with automatic follow-up responses, `response.speak` for scripted text without the LLM, back-channel interjections, filler responses and prompt caching on Anthropic models
- Same company: Inworld TTS is listed as inworld-tts and Inworld STT as inworld-stt. Ultravox, which Inworld acquired, is listed separately as ultravox and runs its own speech model
- Releases: Dated Realtime release notes on 21 July, 14 September, 23 September and 16 October 2026
- Prices: Speech recognition in a session $0.0025 per minute of audio; Agent speech, TTS-2 $25 per 1M characters

- Scores: Reliability 62, Performance pending, Schema & documentation 60, Agent ergonomics 68, Security & auth 58, Payments & pricing 40, Task success pending, Maintenance & community 71, Transparency & trust 63 · total over the 7 assessed categories
- Why: Reliability, Hosted reading of the checklist. · Schema & documentation, No AsyncAPI or other machine-readable file for the socket, and the spec paths redirect (0). · Agent ergonomics, Scored as an API. · Security & auth, Workspace API keys sent as Basic credentials, deleted to revoke, with separate keys per environment advised. · Payments & pricing, No x402, MPP or L402 (0). · Maintenance & community, Release note of 16 October 2026 (`cache_transcript`), 21 days ago (30). · Transparency & trust, Closed service with clear terms naming Theai, Inc.
- Sources: 14, open questions: 3, both in the full twin
- Capabilities: voice.agent, voice.pipeline, voice.tools, voice.telephony
- JSON: https://www.anchorterminal.com/api/v1/tools/inworld-realtime.json
- Verify (for the vendor): the badge `https://www.anchorterminal.com/badges/inworld-realtime.svg` or a link to https://www.anchorterminal.com/tools/inworld-realtime from a page on inworld.ai or one of its subdomains, then `POST https://www.anchorterminal.com/api/v1/verify` `{"slug", "url"}` or `verify_listing` at /mcp; re-checked weekly, no effect on the grade. Snippets in the full twin.
- Support: Discord https://discord.gg/inworld; support@inworld.ai; https://docs.inworld.ai/portal/support; https://docs.inworld.ai/; more in the full twin

## Before you call it

1. Set the auto follow-up off if your client sends its own `response.create` after a tool result, or replies double
2. Read `response.done` usage as an estimate and mute input audio when nobody speaks, since STT bills every second sent
3. Use `response.speak` for fixed greetings, which skips the LLM
4. Treat `unsupported_field` errors as warnings and keep the session open
5. Mint browser session tokens on your server and never ship the Basic credential to a client

## Connect

```bash
npm install -g @inworld/cli
```
Full config and headless snippets are in the full page. Through letme (picks today, calling later): https://letme.dev/inworld-realtime

## Similar tools

| Tool | Grade | Score | Shared capabilities | Slim |
| --- | --- | --- | --- | --- |
| LiveKit Agents | BB | 72.7 | voice.agent, voice.pipeline, voice.tools, voice.telephony | https://www.anchorterminal.com/tools/livekit-agents.min.md |
| ElevenLabs Agents API + MCP | BB | 72.6 | voice.agent, voice.pipeline, voice.tools, voice.telephony | https://www.anchorterminal.com/tools/elevenlabs-agents.min.md |
| Bland AI API + MCP | B | 67 | voice.agent, voice.pipeline, voice.tools, voice.telephony | https://www.anchorterminal.com/tools/bland-ai.min.md |
| Retell AI API + MCP | B | 66.2 | voice.agent, voice.pipeline, voice.tools, voice.telephony | https://www.anchorterminal.com/tools/retell-ai.min.md |
| Pipecat | B | 65.2 | voice.agent, voice.pipeline, voice.tools, voice.telephony | https://www.anchorterminal.com/tools/pipecat.min.md |


## Panel reviews (0, desk reviews from public material, no calls made)