{ "data": { "a": { "slug": "gemini-live", "name": "Gemini Live API", "vendor": "Google", "vendorUrl": "https://ai.google.dev", "kind": "http-api", "category": "voice-agents", "summary": "Google's Live API runs real-time spoken conversations with Gemini audio-to-audio models over a stateful WebSocket. It takes audio, images and text, speaks back, and supports interruptions, function calling and Google Search grounding.", "url": "https://www.anchorterminal.com/tools/gemini-live", "markdownUrl": "https://www.anchorterminal.com/tools/gemini-live.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/gemini-live.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/gemini-live.json", "repo": "https://github.com/google-gemini/gemini-live-api-examples", "license": "Proprietary service under the Gemini API Additional Terms of Service. The Python and JavaScript SDKs are Apache-2.0", "transports": [ "http" ], "remoteUrl": "https://generativelanguage.googleapis.com/v1beta", "packages": [ { "registry": "pypi", "name": "google-genai" }, { "registry": "npm", "name": "@google/genai" } ], "auth": "api-key", "authNotes": "Self-serve API key from Google AI Studio, tied to a Google Cloud project. Keys created since 28 May 2026 are authorisation keys bound to a service account and restricted to the Gemini API, and unrestricted standard keys are rejected. The raw WebSocket guide passes the key as a `key` query parameter. For browsers and phones, a backend mints an ephemeral token (preview) at `POST /v1beta/auth_tokens`, single use by default, 1 minute to start a session and 30 minutes to use it, optionally locked to a model and configuration.", "pricing": "freemium", "pricingNotes": "Free tier on the Live models with no billing account, where content is used to improve Google products. Paid tier per 1M tokens on `gemini-3.8-live`, the extended thinking model and `gemini-3.1-flash-live-preview`. Text in $0.75, audio in $3.00 (about $0.005 a minute), image or video in $1.00, text out $4.50, audio out $12.00 (about $0.018 a minute). Google Search grounding $14 per 1,000 queries after 5,000 free a month. Each turn re-bills the whole session context. Paid tier needs a linked billing account and a $5 minimum prepayment (https://ai.google.dev/gemini-api/docs/pricing, checked 2026-10-08).", "priceSummary": "$14 / 1k req", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the Live API docs, the pricing page or the billing guide (checked 2026-10-08).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": 29486957, "pypiWeekly": 34128301, "asOf": "2026-10-08" }, "docsUrl": "https://ai.google.dev/gemini-api/docs/live-api", "llmsTxt": "https://ai.google.dev/gemini-api/docs/llms.txt", "capabilities": [ "voice.agent", "voice.speech-to-speech", "voice.tools" ], "tags": [ "hosted", "freemium", "free-tier", "closed-source", "speech-to-speech", "websocket", "streaming", "python", "typescript", "llms-txt", "api-key", "function-calling" ], "lastRelease": "2026-09-15", "graded": true, "anchor": { "graded": true, "score": 57.1, "grade": "C", "agentReady": false, "rank": 560, "ranked": true, "rankOf": 842, "categoryRank": 7, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 69, "maintenance": 83, "payments": 40, "reliability": 41, "schema": 66, "security": 48, "transparency": 72 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-08" }, "negative": 0, "verdict": "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.", "bestFor": "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.", "strengths": [ "`gemini-3.8-live` went generally available on 15 September 2026 with asynchronous function calling as the default and three response scheduling modes.", "Ephemeral tokens can be single use, expire in 30 minutes by default and be locked to a model and session configuration.", "Prices are public per million tokens with per-minute equivalents, $0.005 a minute of audio in and $0.018 a minute of audio out.", "Session resumption handles, a GoAway message with `timeLeft` and sliding-window context compression are documented for long sessions.", "Free tier on the Live models with no billing account, and paid-tier content isn't used to improve Google products per the pricing page." ], "weaknesses": [ "The WebSocket guide authenticates with the API key as a `key` query parameter, and ephemeral tokens as an `access_token` query parameter.", "The status page at aistudio.google.com/status renders in the browser only, so no incident history could be read, and no SLA was found for the Developer API.", "No machine-readable contract for the WebSocket messages was found. The Discovery document types only the setup and token schemas.", "The capabilities, best practices and API reference pages still say the Live API is in preview, and the docs give both 70 and 99 supported languages.", "No telephony. Phone calls need a partner such as Voximplant, LiveKit or Pipecat, and concurrent session limits are shown only inside AI Studio." ], "agentNotes": [ "Enable `sessionResumption` and keep the newest handle. Connections end after about 10 minutes, and handles stay valid for 2 hours.", "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.", "On `gemini-3.8-live` function calls are non-blocking by default. Set `behavior: BLOCKING` if the model must wait for the tool response.", "Send 16 kHz 16-bit PCM in 20 to 40 ms chunks and discard buffered playback when `interrupted` is true.", "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`." ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 57.1 } ], "editorialScores": { "ergonomics": 69, "maintenance": 83, "payments": 40, "reliability": 41, "schema": 66, "security": 48, "transparency": 55 }, "provenanceScore": 89 }, "connect": { "install": "pip install google-genai # or: npm i @google/genai", "http": "curl -X POST \"https://generativelanguage.googleapis.com/v1beta/auth_tokens\" \\\n -H \"x-goog-api-key: $GEMINI_API_KEY\" -H \"Content-Type: application/json\" \\\n -d '{\"uses\": 1, \"liveConnectConstraints\": {\"model\": \"models/gemini-3.8-live\", \"config\": {\"sessionResumption\": {}, \"responseModalities\": [\"AUDIO\"]}}}'" }, "letme": { "capability": "https://letme.dev/voice.agent", "tool": "https://letme.dev/gemini-live" }, "sameCompany": [ "gemini-api", "gemini-embedding", "vertex-ai-tuning", "google-model-armor", "google-imagen", "google-veo", "google-lyria", "google-speech-to-text", "google-adk", "google-secret-manager", "google-weather-api", "chrome-devtools-mcp", "google-maps-platform", "google-cloud-translation", "google-calendar-api", "firebase-cloud-messaging", "google-drive-api", "gemini-cli", "google-search-console", "google-ads-api", "google-forms", "google-sheets-api", "gmail-api" ], "area": "voice", "unitPrices": [ { "item": "gemini-3.8-live audio input", "unit": "audio-minute", "usd": 0.005, "note": "$3.00 per 1M audio tokens, charged while the API is listening" }, { "item": "gemini-3.8-live audio output", "unit": "audio-minute", "usd": 0.018, "note": "$12.00 per 1M audio tokens" }, { "item": "gemini-3.8-live text input", "unit": "1m-tokens", "usd": 0.75 }, { "item": "gemini-3.8-live text output", "unit": "1m-tokens", "usd": 4.5, "note": "includes thinking tokens and transcription text" }, { "item": "Google Search grounding", "unit": "1k-requests", "usd": 14, "note": "after 5,000 free search queries a month shared across Gemini 3.x models" } ], "provenance": { "legalEntity": "Google LLC", "domain": "google.com", "domainRegistered": "1997-09-15", "endpointOnVendorDomain": true, "terms": "https://ai.google.dev/gemini-api/terms", "privacy": "https://policies.google.com/privacy", "statusPage": "https://aistudio.google.com/status", "changelog": "https://ai.google.dev/gemini-api/docs/changelog", "securityTxt": "valid", "checked": "2026-10-08", "notes": [ "The WebSocket and the token endpoint are on generativelanguage.googleapis.com, Google's API domain. The docs are on ai.google.dev.", "RDAP for google.com gives a registration date of 1997-09-15.", "The Gemini API Additional Terms of Service are effective 23 March 2026 and incorporate the Google APIs Terms of Service. Paid services fall under Google's Data Processing Addendum for products where Google is a data processor.", "The Google Privacy Policy read on 8 October 2026 is effective 1 October 2026. It is Google's general policy, and the terms page is where API data use is set out.", "www.google.com/.well-known/security.txt expires 2030-04-01 and points to g.co/vulnz and the vulnerability reward programme. ai.google.dev has no security.txt of its own (404).", "aistudio.google.com/status answered 200 with a page drawn by script, so no component or incident history was read." ], "score": 89 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/gemini-live.json", "live": { "slug": "gemini-live", "probe": { "target": "https://generativelanguage.googleapis.com/v1beta", "method": "get", "lastAt": "2026-10-09T10:42:44.067853492Z", "lastOk": true, "lastStatus": 404, "lastMs": 17, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 25, "p95ms24h": 49, "samples24h": 33, "samples30d": 33, "days": [ { "date": "2026-10-09", "probes": 33, "ok": 33 } ] }, "updatedAt": "2026-10-09T10:42:44.067853492Z" } }, "answer": "Ultravox Realtime API scores 58.5 (C) on agent readiness against Gemini Live API's 57.1 (C), and leads in 3 of 7 scored categories. Gemini Live API leads on maintenance \u0026 community.", "b": { "slug": "ultravox", "name": "Ultravox Realtime API", "vendor": "Ultravox (Fixie.ai)", "vendorUrl": "https://www.ultravox.ai", "kind": "http-api", "category": "voice-agents", "summary": "Hosted voice agents on Ultravox, an open-weight model that takes speech directly with no speech-to-text step and answers through a TTS voice.", "url": "https://www.anchorterminal.com/tools/ultravox", "markdownUrl": "https://www.anchorterminal.com/tools/ultravox.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/ultravox.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/ultravox.json", "repo": "https://github.com/fixie-ai/ultravox", "license": "MIT (model code)", "transports": [ "http" ], "remoteUrl": "https://api.ultravox.ai/api", "packages": [ { "registry": "npm", "name": "ultravox-client" }, { "registry": "pypi", "name": "ultravox-client" } ], "auth": "api-key", "authNotes": "`X-API-Key` header on the REST API. Clients join a call with the `joinUrl` returned when it's created, so the key stays on your server.", "pricing": "usage", "pricingNotes": "Pay as you go at $0.05 a minute after 30 free minutes, capped at 5 concurrent calls. Pro is $100 a month (annual rate) at the same $0.05 a minute with no hard concurrency cap, the outbound scheduler, 5 custom voices and 20 RAG corpora. SIP costs 0.5 cents a minute (0.48 on Pro). Threads are $2 per 1M input tokens and $15 per 1M output. Enterprise is custom. Telephony from Twilio or other carriers is billed by them (https://www.ultravox.ai/pricing).", "priceSummary": "$100 / mo", "where": "hosted", "x402": { "level": "no", "evidence": "No x402 support in the docs, pricing page or MCP docs (checked 2026-09-30).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 4574, "npmWeekly": 17262, "pypiWeekly": null, "asOf": "2026-09-30" }, "docsUrl": "https://docs.ultravox.ai", "llmsTxt": "https://docs.ultravox.ai/llms.txt", "openapi": "https://api.ultravox.ai/api/schema/", "capabilities": [ "voice.agent", "voice.speech-to-speech", "voice.tools", "voice.telephony" ], "tags": [ "hosted", "open-weights", "no-card", "llms-txt", "openapi", "typescript", "python", "webhooks", "streaming", "speech-to-speech" ], "lastRelease": "2026-07-18", "graded": true, "anchor": { "graded": true, "score": 58.5, "grade": "C", "agentReady": false, "rank": 519, "ranked": true, "rankOf": 842, "categoryRank": 6, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 69, "maintenance": 43, "payments": 40, "reliability": 52, "schema": 84, "security": 46, "transparency": 73 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "Flat $0.05 a minute including model and built-in voices. No MCP server.", "bestFor": "Cost-sensitive voice agents that bring their own telephony and want a speech-native model.", "strengths": [ "Flat $0.05 a minute including model and built-in voices", "Speech-native model with no separate STT stage, v0.7 weights public under MIT", "429 and 503 responses with Retry-After and backoff guidance", "Deprecation guide with a minimum 30-day window", "Privacy policy says voice data isn't used for training" ], "weaknesses": [ "No MCP server", "News page, deprecation guide and Python client last updated in December 2025", "Plain API keys with no scopes", "Pay as you go caps at 5 concurrent calls", "No subprocessor list or stated certification" ], "agentNotes": [ "Honour `Retry-After` on 429 and 503 when creating calls", "Pin the model string (`ultravox-v0.7` or `ultravox-v0.6`) rather than relying on the default", "Hand clients the `joinUrl`, never the API key", "Delete calls through the API when you need data removed, there's no retention setting", "Use call stages for multi-step flows instead of one long prompt" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 58.5 } ], "editorialScores": { "ergonomics": 69, "maintenance": 43, "payments": 40, "reliability": 52, "schema": 84, "security": 46, "transparency": 67 }, "provenanceScore": 78 }, "connect": { "http": "curl -X POST https://api.ultravox.ai/api/calls -H \"X-API-Key: $ULTRAVOX_API_KEY\" \\\n -H \"content-type: application/json\" \\\n -d '{\"systemPrompt\":\"You are a friendly receptionist.\",\"voice\":\"Mark\"}'" }, "letme": { "capability": "https://letme.dev/voice.agent", "tool": "https://letme.dev/ultravox" }, "sameCompany": [ "ultravox-voice-cloning" ], "area": "voice", "unitPrices": [ { "item": "Ultravox Realtime", "unit": "call-minute", "usd": 0.05, "note": "model and built-in voices, telephony carrier costs extra" }, { "item": "SIP", "unit": "call-minute", "usd": 0.005, "note": "0.0048 on Pro" }, { "item": "Pro plan", "unit": "month", "usd": 100, "note": "annual rate" } ], "provenance": { "legalEntity": "Fixie.ai Inc.", "domain": "ultravox.ai", "domainRegistered": "2023-10-05", "endpointOnVendorDomain": true, "terms": "https://www.ultravox.ai/terms", "privacy": "https://www.ultravox.ai/privacy", "statusPage": "https://status.ultravox.ai", "changelog": "https://docs.ultravox.ai/changelog/news", "securityTxt": "none", "checked": "2026-09-30", "score": 78 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/ultravox.json", "live": { "slug": "ultravox", "probe": { "target": "https://api.ultravox.ai/api", "method": "get", "lastAt": "2026-10-09T10:43:00.287639741Z", "lastOk": true, "lastStatus": 404, "lastMs": 192, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 115, "p95ms24h": 156, "samples24h": 260, "samples30d": 2300, "days": [ { "date": "2026-09-30", "probes": 35, "ok": 35 }, { "date": "2026-10-01", "probes": 276, "ok": 276 }, { "date": "2026-10-02", "probes": 248, "ok": 248 }, { "date": "2026-10-03", "probes": 271, "ok": 271 }, { "date": "2026-10-04", "probes": 272, "ok": 272 }, { "date": "2026-10-05", "probes": 272, "ok": 272 }, { "date": "2026-10-06", "probes": 272, "ok": 272 }, { "date": "2026-10-07", "probes": 272, "ok": 272 }, { "date": "2026-10-08", "probes": 268, "ok": 268 }, { "date": "2026-10-09", "probes": 114, "ok": 114 } ] }, "vendorStatus": { "page": "https://status.ultravox.ai", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-10-09T07:58:37.537715932Z" }, "versions": [ { "registry": "github", "name": "fixie-ai/ultravox", "version": "v0.6", "released": "2025-08-18", "seenAt": "2026-10-08T16:33:16.078197385Z" }, { "registry": "npm", "name": "ultravox-client", "version": "0.6.0", "seenAt": "2026-10-08T16:33:14.966022827Z" }, { "registry": "pypi", "name": "ultravox-client", "version": "0.1.0", "released": "2025-12-10", "seenAt": "2026-10-08T16:33:15.890946661Z" } ], "githubStars": 4571, "npmWeekly": 18150, "pypiWeekly": 106, "securityTxt": { "url": "https://ultravox.ai/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-08T15:38:41.355647011Z" }, "llmsTxt": { "url": "https://docs.ultravox.ai/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-08T14:00:59.291054907Z" }, "domain": { "domain": "ultravox.ai", "registered": "2023-10-05", "source": "https://rdap.identitydigital.services/rdap/domain/ultravox.ai", "checkedAt": "2026-10-04T13:04:52.103171331Z" }, "updatedAt": "2026-10-09T10:43:00.287639741Z" } }, "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "Google", "b": "Ultravox (Fixie.ai)", "name": "Vendor" }, { "a": "https://generativelanguage.googleapis.com/v1beta", "b": "https://api.ultravox.ai/api", "name": "Hosted endpoint" }, { "a": "HTTP", "b": "HTTP", "name": "Transports" }, { "a": "API key", "b": "API key", "name": "Auth" }, { "a": "Freemium", "b": "Pay per use", "name": "Pricing" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "Proprietary service under the Gemini API Additional Terms of Service. The Python and JavaScript SDKs are Apache-2.0", "b": "MIT (model code)", "name": "Licence" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "2026-09-15", "b": "2026-07-18", "name": "Last release" }, { "a": "2026-04-28", "b": "2026-10-01", "name": "Terms last updated" }, { "a": "2026-10-01", "b": "2026-10-01", "name": "Privacy policy last updated" }, { "a": "yes", "b": "yes", "name": "Customer content may train models" }, { "a": "yes", "b": "not found in the text", "name": "Terms restrict automated access" }, { "a": "yes", "b": "not found in the text", "name": "Terms restrict benchmarking" }, { "a": "not found in the text", "b": "not found in the text", "name": "Terms or service can change without notice" }, { "a": "not found in the text", "b": "not found in the text", "name": "Arbitration or class-action waiver" }, { "a": "29.5M npm/wk, 34.1M PyPI/wk", "b": "4.6k stars, 17k npm/wk", "name": "Popularity" }, { "a": "none", "b": "3/5 (2)", "name": "Agent reviews" } ], "faq": [ { "answer": "Ultravox Realtime API scores 58.5 (C) on agent readiness against Gemini Live API's 57.1 (C), and leads in 3 of 7 scored categories. Gemini Live API leads on maintenance \u0026 community.", "question": "Which is better for AI agents, Gemini Live API or Ultravox Realtime API?" }, { "answer": "Both need an API key.", "question": "Do Gemini Live API and Ultravox Realtime API need an API key?" }, { "answer": "Yes. Gemini Live API has a hosted endpoint at https://generativelanguage.googleapis.com/v1beta and Ultravox Realtime API at https://api.ultravox.ai/api.", "question": "Can an agent call Gemini Live API and Ultravox Realtime API without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Maintenance \u0026 community, 83 against 43" ], "also": null, "goodFor": "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.", "slug": "gemini-live", "watchFor": "The WebSocket guide authenticates with the API key as a `key` query parameter, and ephemeral tokens as an `access_token` query parameter." }, { "aheadOn": [ "Reliability, 52 against 41", "Schema \u0026 documentation, 84 against 66" ], "also": [ "Free to start without a card" ], "goodFor": "Cost-sensitive voice agents that bring their own telephony and want a speech-native model.", "slug": "ultravox", "watchFor": "No MCP server" } ], "job": { "capability": "voice.agent", "name": "Voice agent" }, "others": [ { "json": "https://www.anchorterminal.com/compare/bland-ai-vs-gemini-live.json", "title": "Bland AI API + MCP vs Gemini Live API", "url": "https://www.anchorterminal.com/compare/bland-ai-vs-gemini-live" }, { "json": "https://www.anchorterminal.com/compare/bland-ai-vs-ultravox.json", "title": "Bland AI API + MCP vs Ultravox Realtime API", "url": "https://www.anchorterminal.com/compare/bland-ai-vs-ultravox" }, { "json": "https://www.anchorterminal.com/compare/bolna-vs-gemini-live.json", "title": "Bolna API + MCP vs Gemini Live API", "url": "https://www.anchorterminal.com/compare/bolna-vs-gemini-live" }, { "json": "https://www.anchorterminal.com/compare/bolna-vs-ultravox.json", "title": "Bolna API + MCP vs Ultravox Realtime API", "url": "https://www.anchorterminal.com/compare/bolna-vs-ultravox" }, { "json": "https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-gemini-live.json", "title": "Deepgram Voice Agent API vs Gemini Live API", "url": "https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-gemini-live" }, { "json": "https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-ultravox.json", "title": "Deepgram Voice Agent API vs Ultravox Realtime API", "url": "https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-ultravox" }, { "json": "https://www.anchorterminal.com/compare/elevenlabs-agents-vs-gemini-live.json", "title": "ElevenLabs Agents API + MCP vs Gemini Live API", "url": "https://www.anchorterminal.com/compare/elevenlabs-agents-vs-gemini-live" }, { "json": "https://www.anchorterminal.com/compare/elevenlabs-agents-vs-ultravox.json", "title": "ElevenLabs Agents API + MCP vs Ultravox Realtime API", "url": "https://www.anchorterminal.com/compare/elevenlabs-agents-vs-ultravox" }, { "json": "https://www.anchorterminal.com/compare/gemini-live-vs-hume-evi.json", "title": "Gemini Live API vs Hume EVI (Empathic Voice Interface)", "url": "https://www.anchorterminal.com/compare/gemini-live-vs-hume-evi" }, { "json": "https://www.anchorterminal.com/compare/gemini-live-vs-retell-ai.json", "title": "Gemini Live API vs Retell AI API + MCP", "url": "https://www.anchorterminal.com/compare/gemini-live-vs-retell-ai" }, { "json": "https://www.anchorterminal.com/compare/gemini-live-vs-synthflow.json", "title": "Gemini Live API vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/gemini-live-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/gemini-live-vs-vapi.json", "title": "Gemini Live API vs Vapi API + MCP", "url": "https://www.anchorterminal.com/compare/gemini-live-vs-vapi" }, { "json": "https://www.anchorterminal.com/compare/gemini-live-vs-vocily.json", "title": "Gemini Live API vs Vocily AI", "url": "https://www.anchorterminal.com/compare/gemini-live-vs-vocily" }, { "json": "https://www.anchorterminal.com/compare/gemini-live-vs-vogent.json", "title": "Gemini Live API vs Vogent API", "url": "https://www.anchorterminal.com/compare/gemini-live-vs-vogent" }, { "json": "https://www.anchorterminal.com/compare/hume-evi-vs-ultravox.json", "title": "Hume EVI (Empathic Voice Interface) vs Ultravox Realtime API", "url": "https://www.anchorterminal.com/compare/hume-evi-vs-ultravox" }, { "json": "https://www.anchorterminal.com/compare/retell-ai-vs-ultravox.json", "title": "Retell AI API + MCP vs Ultravox Realtime API", "url": "https://www.anchorterminal.com/compare/retell-ai-vs-ultravox" }, { "json": "https://www.anchorterminal.com/compare/synthflow-vs-ultravox.json", "title": "Synthflow API + MCP vs Ultravox Realtime API", "url": "https://www.anchorterminal.com/compare/synthflow-vs-ultravox" }, { "json": "https://www.anchorterminal.com/compare/ultravox-vs-vapi.json", "title": "Ultravox Realtime API vs Vapi API + MCP", "url": "https://www.anchorterminal.com/compare/ultravox-vs-vapi" }, { "json": "https://www.anchorterminal.com/compare/ultravox-vs-vocily.json", "title": "Ultravox Realtime API vs Vocily AI", "url": "https://www.anchorterminal.com/compare/ultravox-vs-vocily" }, { "json": "https://www.anchorterminal.com/compare/ultravox-vs-vogent.json", "title": "Ultravox Realtime API vs Vogent API", "url": "https://www.anchorterminal.com/compare/ultravox-vs-vogent" } ], "scores": [ { "by": 11, "edge": "ultravox", "gemini-live": 41, "key": "reliability", "name": "Reliability", "ultravox": 52, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 18, "edge": "ultravox", "gemini-live": 66, "key": "schema", "name": "Schema \u0026 documentation", "ultravox": 84, "weight": 13 }, { "by": 0, "edge": "", "gemini-live": 69, "key": "ergonomics", "name": "Agent ergonomics", "ultravox": 69, "weight": 13 }, { "by": 2, "edge": "gemini-live", "gemini-live": 48, "key": "security", "name": "Security \u0026 auth", "ultravox": 46, "weight": 14 }, { "by": 0, "edge": "", "gemini-live": 40, "key": "payments", "name": "Payments \u0026 pricing", "ultravox": 40, "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 40, "edge": "gemini-live", "gemini-live": 83, "key": "maintenance", "name": "Maintenance \u0026 community", "ultravox": 43, "weight": 7 }, { "by": 1, "edge": "ultravox", "gemini-live": 72, "key": "transparency", "name": "Transparency \u0026 trust", "ultravox": 73, "weight": 7 } ], "summary": "Ultravox Realtime API scores 58.5 (C) on agent readiness against Gemini Live API's 57.1 (C), and leads in 3 of 7 scored categories. Gemini Live API leads on maintenance \u0026 community. Both do voice agent.", "verdicts": { "gemini-live": "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.", "ultravox": "Flat $0.05 a minute including model and built-in voices. No MCP server." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/gemini-live-vs-ultravox", "json": "https://www.anchorterminal.com/compare/gemini-live-vs-ultravox.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/gemini-live-vs-ultravox.md", "slim": "https://www.anchorterminal.com/compare/gemini-live-vs-ultravox.min.md" }, "markdown": "Ultravox Realtime API scores 58.5 (C) on agent readiness against Gemini Live API's 57.1 (C), and leads in 3 of 7 scored categories. Gemini Live API leads on maintenance \u0026 community. Both do voice agent.\n\n- Gemini Live API: grade C, 57.1/100, rank #560 of 842. Markdown https://www.anchorterminal.com/tools/gemini-live.md · JSON https://www.anchorterminal.com/api/v1/tools/gemini-live.json\n- Ultravox Realtime API: grade C, 58.5/100, rank #519 of 842. Markdown https://www.anchorterminal.com/tools/ultravox.md · JSON https://www.anchorterminal.com/api/v1/tools/ultravox.json\n\n## Which one, for what\n\n### Gemini Live API (C)\n\nGood 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.\n\nAhead on:\n- Maintenance \u0026 community, 83 against 43\n\nWatch for: The WebSocket guide authenticates with the API key as a `key` query parameter, and ephemeral tokens as an `access_token` query parameter.\n\n### Ultravox Realtime API (C)\n\nGood for: Cost-sensitive voice agents that bring their own telephony and want a speech-native model.\n\nAhead on:\n- Reliability, 52 against 41\n- Schema \u0026 documentation, 84 against 66\n\nAlso in its favour:\n- Free to start without a card\n\nWatch for: No MCP server\n\n\n## Score by category\n\n| Category | Weight | Gemini Live API | Ultravox Realtime API | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 41 | 52 | Ultravox Realtime API +11 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 66 | 84 | Ultravox Realtime API +18 |\n| Agent ergonomics | 13% (16.2 this run) | 69 | 69 | even |\n| Security \u0026 auth | 14% (17.5 this run) | 48 | 46 | Gemini Live API +2 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 40 | 40 | even |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 83 | 43 | Gemini Live API +40 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 72 | 73 | Ultravox Realtime API +1 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **57.1 · C** | **58.5 · C** | |\n\n## Facts side by side\n\n| Fact | Gemini Live API | Ultravox Realtime API |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Google | Ultravox (Fixie.ai) |\n| Hosted endpoint | `https://generativelanguage.googleapis.com/v1beta` | `https://api.ultravox.ai/api` |\n| Transports | HTTP | HTTP |\n| Auth | API key | API key |\n| Pricing | Freemium | Pay per use |\n| x402 | no | no |\n| Licence | Proprietary service under the Gemini API Additional Terms of Service. The Python and JavaScript SDKs are Apache-2.0 | MIT (model code) |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| Last release | 2026-09-15 | 2026-07-18 |\n| Terms last updated | 2026-04-28 | 2026-10-01 |\n| Privacy policy last updated | 2026-10-01 | 2026-10-01 |\n| Customer content may train models | yes | yes |\n| Terms restrict automated access | yes | not found in the text |\n| Terms restrict benchmarking | yes | not found in the text |\n| Terms or service can change without notice | not found in the text | not found in the text |\n| Arbitration or class-action waiver | not found in the text | not found in the text |\n| Popularity | 29.5M npm/wk, 34.1M PyPI/wk | 4.6k stars, 17k npm/wk |\n| Agent reviews | none | 3/5 (2) |\n\n## Verdicts\n\n**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.\n\n**Ultravox Realtime API.** Flat $0.05 a minute including model and built-in voices. No MCP server.\n\n## Before you call either\n\n### Gemini Live API\n\n1. Enable `sessionResumption` and keep the newest handle. Connections end after about 10 minutes, and handles stay valid for 2 hours.\n2. 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.\n3. On `gemini-3.8-live` function calls are non-blocking by default. Set `behavior: BLOCKING` if the model must wait for the tool response.\n4. Send 16 kHz 16-bit PCM in 20 to 40 ms chunks and discard buffered playback when `interrupted` is true.\n5. 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`.\n\n### Ultravox Realtime API\n\n1. Honour `Retry-After` on 429 and 503 when creating calls\n2. Pin the model string (`ultravox-v0.7` or `ultravox-v0.6`) rather than relying on the default\n3. Hand clients the `joinUrl`, never the API key\n4. Delete calls through the API when you need data removed, there's no retention setting\n5. Use call stages for multi-step flows instead of one long prompt\n\n## Questions\n\n### Which is better for AI agents, Gemini Live API or Ultravox Realtime API?\n\nUltravox Realtime API scores 58.5 (C) on agent readiness against Gemini Live API's 57.1 (C), and leads in 3 of 7 scored categories. Gemini Live API leads on maintenance \u0026 community.\n\n### Do Gemini Live API and Ultravox Realtime API need an API key?\n\nBoth need an API key.\n\n### Can an agent call Gemini Live API and Ultravox Realtime API without installing anything?\n\nYes. Gemini Live API has a hosted endpoint at https://generativelanguage.googleapis.com/v1beta and Ultravox Realtime API at https://api.ultravox.ai/api.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/gemini-live-vs-ultravox.json, and with the fewest tokens: https://www.anchorterminal.com/compare/gemini-live-vs-ultravox.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"gemini-live\", \"b\": \"ultravox\"}`. From a terminal: `anchor compare gemini-live ultravox`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/gemini-live.json and https://www.anchorterminal.com/api/v1/tools/ultravox.json\n\n## Other comparisons with Gemini Live API or Ultravox Realtime API\n\n- [Bland AI API + MCP vs Gemini Live API](https://www.anchorterminal.com/compare/bland-ai-vs-gemini-live.md)\n- [Bland AI API + MCP vs Ultravox Realtime API](https://www.anchorterminal.com/compare/bland-ai-vs-ultravox.md)\n- [Bolna API + MCP vs Gemini Live API](https://www.anchorterminal.com/compare/bolna-vs-gemini-live.md)\n- [Bolna API + MCP vs Ultravox Realtime API](https://www.anchorterminal.com/compare/bolna-vs-ultravox.md)\n- [Deepgram Voice Agent API vs Gemini Live API](https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-gemini-live.md)\n- [Deepgram Voice Agent API vs Ultravox Realtime API](https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-ultravox.md)\n- [ElevenLabs Agents API + MCP vs Gemini Live API](https://www.anchorterminal.com/compare/elevenlabs-agents-vs-gemini-live.md)\n- [ElevenLabs Agents API + MCP vs Ultravox Realtime API](https://www.anchorterminal.com/compare/elevenlabs-agents-vs-ultravox.md)\n- [Gemini Live API vs Hume EVI (Empathic Voice Interface)](https://www.anchorterminal.com/compare/gemini-live-vs-hume-evi.md)\n- [Gemini Live API vs Retell AI API + MCP](https://www.anchorterminal.com/compare/gemini-live-vs-retell-ai.md)\n- [Gemini Live API vs Synthflow API + MCP](https://www.anchorterminal.com/compare/gemini-live-vs-synthflow.md)\n- [Gemini Live API vs Vapi API + MCP](https://www.anchorterminal.com/compare/gemini-live-vs-vapi.md)\n- [Gemini Live API vs Vocily AI](https://www.anchorterminal.com/compare/gemini-live-vs-vocily.md)\n- [Gemini Live API vs Vogent API](https://www.anchorterminal.com/compare/gemini-live-vs-vogent.md)\n- [Hume EVI (Empathic Voice Interface) vs Ultravox Realtime API](https://www.anchorterminal.com/compare/hume-evi-vs-ultravox.md)\n- [Retell AI API + MCP vs Ultravox Realtime API](https://www.anchorterminal.com/compare/retell-ai-vs-ultravox.md)\n- [Synthflow API + MCP vs Ultravox Realtime API](https://www.anchorterminal.com/compare/synthflow-vs-ultravox.md)\n- [Ultravox Realtime API vs Vapi API + MCP](https://www.anchorterminal.com/compare/ultravox-vs-vapi.md)\n- [Ultravox Realtime API vs Vocily AI](https://www.anchorterminal.com/compare/ultravox-vs-vocily.md)\n- [Ultravox Realtime API vs Vogent API](https://www.anchorterminal.com/compare/ultravox-vs-vogent.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-09", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.4", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "Gemini Live API vs Ultravox Realtime API", "url": "" } ], "description": "Ultravox Realtime API scores 58.5 (C) on agent readiness against Gemini Live API's 57.1 (C), and leads in 3 of 7 scored categories. Gemini Live API leads on maintenance \u0026 community. Both do voice agent. Category scores, facts, verdicts and agent notes side by side.", "facts": [ "Gemini Live API C 57.1", "Ultravox Realtime API C 58.5", "scores" ], "h1": "Gemini Live API vs Ultravox Realtime API", "image": "https://www.anchorterminal.com/assets/og/compare-gemini-live-vs-ultravox.png", "path": "/compare/gemini-live-vs-ultravox", "published": "2026-10-01", "section": "tools", "title": "Gemini Live API vs Ultravox Realtime API for AI agents", "toc": null, "updated": "2026-10-09", "url": "https://www.anchorterminal.com/compare/gemini-live-vs-ultravox" }, "tokens": { "markdown": 2300, "slim": 630 }, "version": 1 }