Head to head · Voice agents · October 2026 research run

Gemini Live API vs Inworld Realtime API

Inworld Realtime API scores 60.1 (C) on agent readiness against Gemini Live API's 54.1 (C), and leads in 2 of 7 scored categories. Gemini Live API leads on schema & documentation, maintenance & community and transparency & trust. Both do voice agents.

Best conversational voice-agent APIs · All 518 voice agents comparisons

Which one, for what

Gemini Live API C

Best for Teams building their own voice or vision assistant on a single speech-to-speech model with function calling and Search grounding, who can run a backend for tokens and audio transport.

Ahead on

  • Schema & documentation, 66 against 60
  • Maintenance & community, 83 against 71
  • Transparency & trust, 72 against 63

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

The WebSocket guide authenticates with the API key as a key query parameter, and ephemeral tokens as an access_token query parameter.

Inworld Realtime API C

Best for Teams moving off OpenAI's Realtime API who want a choice of LLM and Inworld voices.

Ahead on

  • Reliability, 62 against 41
  • Security & auth, 58 against 48

Also in its favour

  • No incidents deducted, where Gemini Live API loses 3 points for them

Watch for

No per-minute price. A session's cost depends on STT, LLM tokens and TTS characters, and interrupted segments are still billed

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Reliability Inworld Realtime API +21

Gemini Live API 41

Graded as a hosted API on the Gemini Developer API. A status page exists at aistudio.google.com/status, but on 4 November it still returned a script shell titled "Google AI Studio" with no components or history we could read (10 of 20, and 5 of 30 for the incident line with no readable record). Session limits are published, 15 minutes for audio and 2 for audio with video without compression, connections of about 10 minutes, and spend limits per 10 minutes of $10 on Tier 1 and $200 on Tiers 2 and 3. Per-model request limits and concurrent sessions are shown only in AI Studio, so the earlier partial 8 of 15 is kept. The server sends a GoAway message with timeLeft before closing, session resumption handles last 2 hours, and the troubleshooting guide gives exponential backoff with jitter for 429 and 503 (12 of 15). No SLA found for the Developer API (0). gemini-3.8-live is stable and generally available since 15 September, but the endpoint is v1beta, ephemeral tokens are in preview and the capabilities guide and API reference still label the Live API a preview, so the earlier partial 6 of 10 is kept.

Inworld Realtime API 62

Hosted reading of the checklist. status.inworld.ai is a public status page (20), with history we couldn't read, as on inworld-tts (5). Concurrent sessions are published per plan, 10 on On-Demand up to 1,000 on Growth (15). The rate limits page gives exponential backoff with jitter and Retry-After on longer windows, and sessions emit rate_limits.updated, with nothing on reconnecting a dropped session (12 of 15). An SLA appears only in the Enterprise column, with no terms (0). No preview or beta label on the Realtime API (10). 20 + 5 + 15 + 12 + 0 + 10 = 62.

Maintenance & community Gemini Live API +12

Gemini Live API 83

google-genai 2.34.0 (29 October 2026) changes the Live client, adding base_url, api_version and headers to LiveConnectConfig.http_options and a header fix in live.py, 6 days before the check (30). In the 90 days from 6 August, the changelog's gemini-3.5-transcribe-live (26 August) and 3.8 Live GA (15 September) entries, and Python SDK releases that change Live code, 2.18.0 (12 August), 2.19.0 (19 August), 2.23.0 (10 September), 2.26.0 (30 September), 2.30.0 (13 October), 2.32.0 (21 October), 2.33.0 (22 October) and 2.34.0 (29 October) (20). Closed service with a changelog updated several times a month. Support channels were not tested (10 of 15). Current official SDKs, google-genai v2.34.0 and @google/genai v2.32.0, both tagged 29 October (15). Apache-2.0 SDKs with type-check workflows in the Python repository and Node 20 or later stated. CI results were not read (8 of 10).

Inworld Realtime API 71

Release note of 16 October 2026 (cache_transcript), 21 days ago (30). Three dated Realtime entries in the 90 days from 8 August, on 14 September, 23 September and 16 October (20). Discord and support@inworld.ai, with no evidence of answers read (8 of 15). Works with OpenAI's Realtime clients and the CLI is current at 1.5.0, but there is no Inworld Realtime SDK (8 of 15). CLI on npm under MIT, CI not read (5 of 10). Total 71.

Security & auth Inworld Realtime API +10

Gemini Live API 48

Keys created since 28 May 2026 are authorisation keys bound to a service account and restricted to the Gemini API, with IP and origin restrictions, a leak checklist and rejection of unrestricted standard keys. Ephemeral tokens add expiry and use counts (25 of 30). The WebSocket guide, re-read on 4 November, still documents the API key as a key query parameter and ephemeral tokens as an access_token query parameter, so we deduct 10 on that documentation (15 of 30). Ephemeral tokens can be locked to a model and configuration and to one session, which keeps system instructions server side. There is no approval step for tool calls, which the client runs itself (12 of 20). The model hears callers and can ground on Google Search, and the best practices page covers guardrails in system instructions but not prompt injection (5 of 15). Opt-in logs exist for billed projects, and we did not confirm they cover Live sessions. Usage is visible per project (8 of 15). security.txt on google.com valid to 2030 with a vulnerability reward programme. No certification naming the Developer API was found (8 of 20).

Inworld Realtime API 58

Workspace API keys sent as Basic credentials, deleted to revoke, with separate keys per environment advised. The CLI mints read-only keys unless --write is given, but write toggles cover only the Voice and Router APIs, so no key is limited to one product. Browsers use short-lived tokens minted server side. Session IDs, not secrets, go in the URL (25 of 30). Tools run in the client, so the developer approves side effects, with no approval step in the API (10 of 20). The agent listens to callers and passes their speech to an LLM, and no prompt-injection guidance was found (5 of 15). Usage per key and a Performance page with errors and throttling (8 of 15). SOC 2 Type II and HIPAA claimed and a vulnerability report form, with no security.txt or bug bounty, per the 4 November reading (10 of 20). Total 58. Zero data retention covers session content from the Developer plan up, but not requests routed to third-party LLM providers.

Transparency & trust Gemini Live API +9

Gemini Live API 72

Closed service with clear terms, SDKs under Apache-2.0 (15 of 30). The terms, pricing page and zero data retention page agree that free-tier content improves Google products and paid content does not. The terms say abuse logs are kept for a limited period and the abuse monitoring page gives 55 days. Session state is kept up to 24 hours when resumption is on, and Search grounding data 30 days (20 of 30). A deprecations table gives earliest shutdown dates and replacements, with 17 November 2026 for the two older Live previews, about nine weeks after the replacement shipped, and no stated minimum notice (15 of 20). The terms say data may be stored transiently or cached in any country where Google has facilities. The Data Processing Addendum applies to paid services, and no sub-processor list was read (5 of 20).

Inworld Realtime API 63

Closed service with clear terms naming Theai, Inc. dba Inworld AI (15). The ZDR page says what a session keeps and that third-party LLM requests aren't covered, but the terms and privacy notice disagree on training (12 of 30). Release notes flag potentially breaking changes with the clients affected and what to do, without stating a notice period (14 of 20). US headquarters with EU and India residency on Enterprise, and no sub-processor list in the docs, while sessions may route to third-party LLM providers (10 of 20). Total 51.

Schema & documentation Gemini Live API +6

Gemini Live API 66

No AsyncAPI or similar file for the WebSocket messages was found. The keyless Discovery document (revision 20261006) types auth_tokens.create and five related schemas, BidiGenerateContentSetup among them, but not the client and server messages (8 of 25). llms.txt with a Markdown twin of every page (10). The capabilities guide, model comparison table and best practices page say when to use each model, voice activity mode and tool behaviour (16 of 20). The reference at aistudio.google.com/api-reference/live lists every message with field types, enums such as ActivityHandling, TurnCoverage and the sensitivity levels, and required marks, as tables and not as a schema (12 of 15). Python and JavaScript examples on every guide, but no list of WebSocket close codes or Live error responses was found (8 of 15). Dated changelog and versioned model names, less 3 because the tools page omits the 3.8 models, the overview says 70 languages where the capabilities guide lists 99, and preview banners remain on two pages after general availability (12 of 15). Docs moved from ai.google.dev to aistudio.google.com by 4 November 2026; the pages not re-read stand per the 8 October check.

Inworld Realtime API 60

No AsyncAPI or other machine-readable file for the socket, and the spec paths redirect (0). llms.txt, Markdown twins and a docs MCP server (10). The overview, OpenAI migration guide, providerData reference and the billing page's account of how a session is counted say what to use when (16 of 20). The reference lists every client and server event with field types and required marks, as text rather than a schema (12 of 15). JavaScript and Python example projects and an error event with type, code and param, without a list of codes (9 of 15). Dated release notes with affected clients and required actions, but no API version beyond /v1 (13 of 15). Total 60.

Score by category

CategoryWeight this runGemini Live APIInworld Realtime APIEdge
Reliability16%204162Inworld Realtime API +21
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26660Gemini Live API +6
Agent ergonomics13%16.26968Gemini Live API +1
Security & auth14%17.54858Inworld Realtime API +10
Payments & pricing10%12.54040even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88371Gemini Live API +12
Transparency & trust7%8.87263Gemini Live API +9
Negative events≤15-30
TotalC 54.1/100C 60.1/100

Facts side by side

FactGemini Live APIInworld Realtime API
KindHTTP APIHTTP API
VendorGoogleInworld AI
Hosted endpointhttps://generativelanguage.googleapis.com/v1betano (local only)
TransportsHTTPwebsocket, HTTP
AuthAPI keyAPI key
PricingFreemiumPay per use
Price for voice agentsnot published$25 per 1M characters
x402nono
LicenceProprietary service under the Gemini API Additional Terms of Service. The Python and JavaScript SDKs are Apache-2.0none
Tools exposednone0
Read-only variant documentednono
llms.txtyesyes
Last release2026-10-292026-10-16
Terms last updated2026-04-282025-06-11
Privacy policy last updated2026-10-012026-01-18
Customer content may train modelsyesnot found in the text
Terms restrict automated accessyesnot found in the text
Terms restrict benchmarkingyesnot found in the text
Terms or service can change without noticenot found in the textnot found in the text
Arbitration or class-action waivernot found in the textnot found in the text
Popularity29.5M npm/wk, 34.1M PyPI/wknone

How the scores have moved

Verdicts

Gemini Live API

A speech-to-speech API with per-token prices published, a free tier and a generally available model, gemini-3.8-live, since 15 September 2026. The documented raw WebSocket connection carries the API key in the URL, connections reset about every 10 minutes, and no SLA or readable incident history was found for the Developer API.

Inworld Realtime API

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.

Before you call either

Gemini Live API

  1. Enable sessionResumption and keep the newest handle. Connections end after about 10 minutes, and handles stay valid for 2 hours.
  2. Set contextWindowCompression with a sliding window. Without it audio sessions stop at 15 minutes and audio with video at 2 minutes, and every turn re-bills the whole context.
  3. On gemini-3.8-live function calls are non-blocking by default. Set behavior: BLOCKING if the model must wait for the tool response.
  4. Keep the API key on a server and send it through the SDK. Give browsers an ephemeral token from POST /v1beta/auth_tokens, locked with liveConnectConstraints.
  5. Use google-genai 2.34.0 or later if you pass a per-request Authorization header. Earlier versions kept it in the client's default headers

Inworld Realtime API

  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

Questions

Which is better for AI agents, Gemini Live API or Inworld Realtime API?

Inworld Realtime API scores 60.1 (C) on agent readiness against Gemini Live API's 54.1 (C), and leads in 2 of 7 scored categories. Gemini Live API leads on schema & documentation, maintenance & community and transparency & trust.

Do Gemini Live API and Inworld Realtime API need an API key?

Both need an API key.

Can an agent call Gemini Live API and Inworld Realtime API without installing anything?

Gemini Live API has a hosted endpoint at https://generativelanguage.googleapis.com/v1beta. No hosted endpoint is listed for Inworld Realtime API.

Other comparisons with Gemini Live API or Inworld Realtime API

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