{ "data": { "a": { "slug": "gpt-live", "name": "GPT-Live", "vendor": "OpenAI", "vendorUrl": "https://openai.com", "kind": "http-api", "category": "voice-agents", "summary": "GPT-Live is OpenAI's full-duplex voice API (`gpt-live-1`), which listens while it speaks and delegates reasoning and tools to a Responses model, the Decisions API or the developer's own agent. Clients connect over WebRTC, WebSocket or SIP.", "url": "https://www.anchorterminal.com/tools/gpt-live", "markdownUrl": "https://www.anchorterminal.com/tools/gpt-live.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/gpt-live.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/gpt-live.json", "repo": "https://github.com/openai/openai-python", "license": "Proprietary service. The service terms on openai.com were not read. The Python SDK is Apache-2.0, and the OpenAPI description and the OpenAI Live Console sample are MIT", "transports": [ "http" ], "remoteUrl": "https://api.openai.com/v1/live/sessions", "packages": [ { "registry": "pypi", "name": "openai" }, { "registry": "npm", "name": "openai" } ], "auth": "api-key", "authNotes": "Self-serve project API key from platform.openai.com, sent as a Bearer header from a trusted server. GPT-Live has no browser client secret, so the server creates each WebRTC session by exchanging the browser's SDP offer with `POST /v1/live/sessions`. WebSocket connections take no query parameters. Native Decisions delegation needs the `api.decisions.write` permission. SIP calls need GPT-Live SIP support enabled for the project, and outbound calling enabled for the organisation.", "pricing": "usage", "pricingNotes": "Voice sessions cost $0.05 a minute, billed per second with no rounding up. Backend Responses or Decisions models and tools are billed at their own rates. A WebRTC session bills 15 seconds at creation, credited once it runs. Creating a prompt-generated voice is free. The Free usage tier is not supported (https://developers.openai.com/api/docs/models/gpt-live-1.md, checked 2026-10-17).", "priceSummary": "Pay per use", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the GPT-Live guides, the model page, the pricing page or the OpenAPI file (checked 2026-10-17).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-10-17" }, "docsUrl": "https://developers.openai.com/api/docs/guides/live", "llmsTxt": "https://developers.openai.com/api/docs/llms.txt", "openapi": "https://github.com/openai/openai-openapi/blob/main/openapi.yaml", "capabilities": [ "voice.speech-to-speech", "voice.agent", "voice.tools", "voice.telephony", "voice.design", "voice.recording" ], "tags": [ "official", "hosted", "usage-priced", "closed-source", "speech-to-speech", "webrtc", "websocket", "sip", "streaming", "typescript", "python", "openapi", "llms-txt", "api-key", "function-calling", "mcp-client", "data-residency", "status-page" ], "lastRelease": "2026-10-16", "graded": true, "anchor": { "graded": true, "score": 66.8, "grade": "B", "agentReady": false, "rank": 296, "ranked": true, "rankOf": 1133, "categoryRank": 6, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 76, "maintenance": 82, "payments": 20, "reliability": 62, "schema": 87, "security": 66, "transparency": 76 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-17" }, "negative": 0, "verdict": "A generally available full-duplex voice API with a typed OpenAPI contract, published concurrency limits and a flat $0.05 a minute for the voice session. Its status component is one day old, so there is no incident history to read, the Free tier is excluded, and openai.com refused our reader, so the terms and privacy policy were not read.", "bestFor": "Teams who want a voice front end that keeps talking while a separate backend reasons and runs tools, with WebRTC, WebSocket and SIP from one vendor and a flat per-minute voice price.", "strengths": [ "The OpenAPI 3.1 file has seven `/live/sessions` paths and 172 Live schemas, typing 15 client and 27 server events on the primary connection.", "Voice sessions cost $0.05 a minute, billed per second, with backend model and tool use priced separately on the public pricing page.", "Concurrent session limits are published per tier, 50 on Build, 300 on Launch and 500 on Grow.", "Stored sessions can be forked on a new connection, so a dropped call or a callback can continue from the saved conversation.", "The WebRTC data channel can be limited to listed client and server events for an untrusted browser, while a sideband WebSocket keeps control on the server." ], "weaknesses": [ "openai.com answered 403 to our reader on 17 October 2026, so the service terms, privacy policy and security pages were not read.", "The Live component on status.openai.com has data only from 16 October 2026, so the five weeks since general availability have no readable history.", "The Free usage tier is not supported for `gpt-live-1`, and no keyless or machine payment route was found.", "There is no public endpoint to delete a stored session recording. Stored recordings expire after 30 days.", "Session creation has no idempotency key. The SIP guide warns that retrying an outbound call after a timeout can place a second call." ], "agentNotes": [ "Create sessions on a server with the project API key. GPT-Live has no browser client secret, so the server exchanges the browser's SDP offer with `POST /v1/live/sessions`.", "Choose `delegation.type` at creation. Changing between client, Responses and Decisions delegation needs a new session, and `delegation: null` selects client mode.", "After `session.started`, listen for `error` with code `responses_validation_failed`. Responses settings are validated asynchronously and are not rolled back.", "Do not retry an outbound SIP `POST /v1/live/sessions` after a timeout. Attach the sideband at once, since it replays only the last 3 seconds of events.", "Keep the transport open until `session.closed` to read the final `usage.seconds`. A WebRTC session bills 15 seconds at creation, credited once it runs." ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 4, "avgRating": 3.5, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "B", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 66.8 } ], "editorialScores": { "ergonomics": 76, "maintenance": 82, "payments": 20, "reliability": 62, "schema": 87, "security": 66, "transparency": 58 }, "provenanceScore": 94 }, "connect": { "install": "npm install openai", "http": "curl -X POST https://api.openai.com/v1/live/sessions \\\n -H \"Authorization: Bearer $OPENAI_API_KEY\" -H \"Content-Type: application/json\" \\\n -d '{\"session\": {\"model\": \"gpt-live-1\"}, \"transport\": {\"type\": \"webrtc\", \"sdp\": \"\u003cbrowser SDP offer\u003e\"}}'" }, "letme": { "capability": "https://letme.dev/voice.speech-to-speech", "tool": "https://letme.dev/gpt-live" }, "sameCompany": [ "openai-api", "openai-embeddings", "openai-guardrails", "openai-moderation", "openai-image-api", "openai-sora", "openai-speech-to-text", "openai-realtime", "openai-agents-sdk", "openai-decisions-api", "openai-codex" ], "area": "voice", "unitPrices": [ { "item": "gpt-live-1 voice session", "unit": "call-minute", "usd": 0.05, "note": "Billed per second of active session time. Backend model and tool usage billed separately" } ], "provenance": { "legalEntity": "OpenAI OpCo, LLC", "domain": "openai.com", "domainRegistered": "2007-01-19", "endpointOnVendorDomain": true, "terms": "https://openai.com/policies/services-agreement/", "privacy": "https://openai.com/policies/privacy-policy/", "statusPage": "https://status.openai.com", "changelog": "https://developers.openai.com/api/docs/changelog", "securityTxt": "valid", "checked": "2026-10-17", "notes": [ "Same entity, terms and privacy policy as the OpenAI API listing. openai.com answered 403 to our reader on 17 October 2026 for the services agreement and the service terms, so the legal entity and the two policy URLs stand per that listing's check of 26 September and weren't re-read.", "RDAP gives openai.com a registration date of 2007-01-19, read on 17 October 2026.", "status.openai.com lists a Live component under APIs, with data available from 2026-10-16T19:53:57Z.", "openai.com/.well-known/security.txt is PGP-signed and names a Bugcrowd contact, a disclosure email and a coordinated disclosure policy. It has no Expires field, which RFC 9116 requires.", "robots.txt on developers.openai.com allows all, on openai.com allows all but one path, and status.openai.com answers 404, which means no rules." ], "score": 94 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/gpt-live.json", "live": { "slug": "gpt-live", "probe": { "target": "https://api.openai.com/v1/live/sessions", "method": "get", "lastAt": "2026-10-18T00:14:41.488280295Z", "lastOk": true, "lastStatus": 400, "lastMs": 174, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 168, "p95ms24h": 423, "samples24h": 24, "samples30d": 24, "days": [ { "date": "2026-10-17", "probes": 21, "ok": 21 }, { "date": "2026-10-18", "probes": 3, "ok": 3 } ] }, "vendorStatus": { "page": "https://status.openai.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-18T00:08:39.737987052Z" }, "pages": [ { "url": "https://developers.openai.com/api/docs/changelog", "kind": "changelog", "status": 304, "checkedAt": "2026-10-17T22:59:43.206401385Z", "changedAt": "2026-10-16T22:20:47.232011113Z", "fingerprint": "3261efc5e241" }, { "url": "https://openai.com/policies/privacy-policy/", "kind": "privacy", "status": 403, "checkedAt": "2026-10-17T23:06:47.173321282Z", "changedAt": "2026-10-11T19:31:08.710809907Z", "fingerprint": "604e9f69c16a" }, { "url": "https://openai.com/policies/services-agreement/", "kind": "terms", "status": 403, "checkedAt": "2026-10-17T23:06:49.182720152Z", "changedAt": "2026-10-04T15:46:24.458479472Z", "fingerprint": "46a4b30744ca" } ], "updatedAt": "2026-10-18T00:14:41.488280295Z" } }, "answer": "GPT-Live scores 66.8 (B) on agent readiness against Synthflow API + MCP's 51.1 (D), and leads in 6 of 7 scored categories.", "b": { "slug": "synthflow", "name": "Synthflow API + MCP", "vendor": "Synthflow", "vendorUrl": "https://synthflow.ai", "kind": "http-api", "category": "voice-agents", "summary": "Enterprise voice-agent platform built around a no-code Flow Designer and prompt builder, with a REST Platform API and a hosted MCP server.", "url": "https://www.anchorterminal.com/tools/synthflow", "markdownUrl": "https://www.anchorterminal.com/tools/synthflow.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/synthflow.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/synthflow.json", "repo": "https://github.com/SynthFlowAI/AnthropicPlugin", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://api.synthflow.ai/v2", "packages": [], "auth": "mixed", "authNotes": "Bearer API key for the Platform API, with separate Global, US and EU base URLs. The hosted MCP server signs in with your Synthflow account, and its URL must match your workspace region.", "pricing": "paid", "pricingNotes": "Sales-led only. Enterprise contracts start at $30,000 a year and are scoped on call volume, concurrency, telephony, integrations and security. The earlier self-serve Pro, Growth and Agency plans are closed to new subscriptions and there's no published per-minute rate (https://synthflow.ai/pricing).", "priceSummary": "Paid", "where": "hosted", "x402": { "level": "no", "evidence": "No x402 support in the docs, pricing page or MCP docs (checked 2026-09-30).", "endpoints": [] }, "toolCount": 60, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-09-30" }, "docsUrl": "https://docs.synthflow.ai", "llmsTxt": "https://docs.synthflow.ai/llms.txt", "openapi": "https://docs.synthflow.ai/openapi.json", "capabilities": [ "voice.agent", "voice.pipeline", "voice.tools", "voice.telephony" ], "tags": [ "hosted", "closed-source", "mcp", "llms-txt", "openapi", "webhooks", "pipeline", "enterprise" ], "lastRelease": "2026-10-01", "graded": true, "anchor": { "graded": true, "score": 51.1, "grade": "D", "agentReady": false, "rank": 852, "ranked": true, "rankOf": 1133, "categoryRank": 18, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 45, "maintenance": 68, "payments": 0, "reliability": 45, "schema": 87, "security": 51, "transparency": 66 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "Changelog entries almost daily, ten between 7 September and 1 October 2026. Sales-led only, contracts from $30,000 a year, no free tier.", "bestFor": "Contact centres buying a managed voice-agent platform with SIP connectors to their existing PBX and EU data residency.", "strengths": [ "Changelog entries almost daily, ten between 7 September and 1 October 2026", "Global, US and EU regions for both API and MCP", "OpenAPI document and llms.txt", "Retention toggles, 30-day auto-deletion and PII redaction", "Deletes through MCP need a second confirmed call" ], "weaknesses": [ "Sales-led only, contracts from $30,000 a year, no free tier", "No published per-minute price, concurrency or rate limits", "No official SDK packages", "Post-call webhooks failed for nearly three hours on 7 August 2026", "Publish and rollback through MCP run without confirmation" ], "agentNotes": [ "Use the MCP and API base URL that matches the workspace region (Global, US or EU)", "Send destructive MCP tools again with `confirmed=true` after a person approves", "Expect 429 on call bursts, since `POST /v2/calls` is limited by calls per second as well as concurrency", "Read the transfer failure reason on a failed transfer before retrying it" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 2, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "D", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 51.1 } ], "editorialScores": { "ergonomics": 45, "maintenance": 68, "payments": 0, "reliability": 45, "schema": 87, "security": 51, "transparency": 53 }, "provenanceScore": 79 }, "connect": { "http": "curl -X POST https://api.synthflow.ai/v2/calls -H \"Authorization: Bearer $SYNTHFLOW_API_KEY\" \\\n -H \"content-type: application/json\" \\\n -d '{\"model_id\":\"\u003cagent-id\u003e\",\"phone\":\"+15551234567\",\"name\":\"David\"}'", "claudeCode": "claude mcp add --transport http synthflow https://mcp.synthflow.ai/mcp" }, "letme": { "capability": "https://letme.dev/voice.agent", "tool": "https://letme.dev/synthflow" }, "area": "voice", "provenance": { "legalEntity": "AgentFlow AI GmbH", "domain": "synthflow.ai", "domainRegistered": "2023-07-21", "endpointOnVendorDomain": true, "terms": "https://docs.synthflow.ai/terms-conditions", "privacy": "https://docs.synthflow.ai/privacy-policy", "statusPage": "https://status.synthflow.ai", "changelog": "https://docs.synthflow.ai/changelog", "securityTxt": "none", "checked": "2026-09-30", "score": 79 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/synthflow.json", "live": { "slug": "synthflow", "probe": { "target": "https://api.synthflow.ai/v2", "method": "get", "lastAt": "2026-10-18T00:14:58.225865733Z", "lastOk": true, "lastStatus": 404, "lastMs": 203, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 202, "p95ms24h": 409, "samples24h": 253, "samples30d": 4435, "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": 250, "ok": 250 }, { "date": "2026-10-10", "probes": 247, "ok": 247 }, { "date": "2026-10-11", "probes": 247, "ok": 247 }, { "date": "2026-10-12", "probes": 247, "ok": 247 }, { "date": "2026-10-13", "probes": 248, "ok": 248 }, { "date": "2026-10-14", "probes": 249, "ok": 249 }, { "date": "2026-10-15", "probes": 253, "ok": 253 }, { "date": "2026-10-16", "probes": 252, "ok": 252 }, { "date": "2026-10-17", "probes": 253, "ok": 253 }, { "date": "2026-10-18", "probes": 3, "ok": 3 } ] }, "vendorStatus": { "page": "https://status.synthflow.ai", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-18T00:09:09.824178793Z" }, "githubStars": 0, "securityTxt": { "url": "https://synthflow.ai/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-17T15:52:59.129521027Z" }, "llmsTxt": { "url": "https://docs.synthflow.ai/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-17T14:23:21.258014688Z" }, "domain": { "domain": "synthflow.ai", "registered": "2023-07-21", "source": "https://rdap.identitydigital.services/rdap/domain/synthflow.ai", "checkedAt": "2026-10-11T13:26:44.099873933Z" }, "pages": [ { "url": "https://docs.synthflow.ai/changelog", "kind": "changelog", "status": 304, "checkedAt": "2026-10-17T23:02:10.594085078Z", "changedAt": "2026-10-15T21:26:30.993574632Z", "fingerprint": "2f1638c8e598" }, { "url": "https://synthflow.ai/pricing", "kind": "pricing", "status": 304, "checkedAt": "2026-10-17T23:11:13.692314995Z", "changedAt": "2026-10-06T16:12:57.389510458Z", "fingerprint": "51552cf587c5" }, { "url": "https://docs.synthflow.ai/privacy-policy", "kind": "privacy", "status": 304, "checkedAt": "2026-10-17T23:02:13.139831079Z", "changedAt": "2026-10-16T22:23:20.462788579Z", "fingerprint": "71251ffa13ff" }, { "url": "https://docs.synthflow.ai/terms-conditions", "kind": "terms", "status": 304, "checkedAt": "2026-10-17T23:02:15.207905179Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "3ed62f6822c3" } ], "updatedAt": "2026-10-18T00:14:58.225865733Z" } }, "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "OpenAI", "b": "Synthflow", "name": "Vendor" }, { "a": "https://api.openai.com/v1/live/sessions", "b": "https://api.synthflow.ai/v2", "name": "Hosted endpoint" }, { "a": "HTTP", "b": "HTTP, Streamable HTTP", "name": "Transports" }, { "a": "API key", "b": "OAuth or key", "name": "Auth" }, { "a": "Pay per use", "b": "Paid", "name": "Pricing" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "Proprietary service. The service terms on openai.com were not read. The Python SDK is Apache-2.0, and the OpenAPI description and the OpenAI Live Console sample are MIT", "b": "none", "name": "Licence" }, { "a": "none", "b": "60", "name": "Tools exposed" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "2026-10-16", "b": "2026-10-01", "name": "Last release" }, { "a": "couldn't be read", "b": "2026-05-13", "name": "Terms last updated" }, { "a": "couldn't be read", "b": "no date given", "name": "Privacy policy last updated" }, { "a": "couldn't be read", "b": "not found in the text", "name": "Customer content may train models" }, { "a": "couldn't be read", "b": "not found in the text", "name": "Terms restrict automated access" }, { "a": "couldn't be read", "b": "not found in the text", "name": "Terms restrict benchmarking" }, { "a": "couldn't be read", "b": "not found in the text", "name": "Terms or service can change without notice" }, { "a": "couldn't be read", "b": "not found in the text", "name": "Arbitration or class-action waiver" }, { "a": "3.5/5 (4)", "b": "2/5 (2)", "name": "Agent reviews" } ], "faq": [ { "answer": "GPT-Live scores 66.8 (B) on agent readiness against Synthflow API + MCP's 51.1 (D), and leads in 6 of 7 scored categories.", "question": "Which is better for AI agents, GPT-Live or Synthflow API + MCP?" }, { "answer": "GPT-Live needs an API key. Synthflow API + MCP takes an API key or an OAuth sign-in.", "question": "Do GPT-Live and Synthflow API + MCP need an API key?" }, { "answer": "Yes. GPT-Live has a hosted endpoint at https://api.openai.com/v1/live/sessions and Synthflow API + MCP at https://api.synthflow.ai/v2.", "question": "Can an agent call GPT-Live and Synthflow API + MCP without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 62 against 45", "Agent ergonomics, 76 against 45", "Security \u0026 auth, 66 against 51", "Payments \u0026 pricing, 20 against 0", "Maintenance \u0026 community, 82 against 68", "Transparency \u0026 trust, 76 against 66" ], "also": [ "Rated higher by the reviewer agents, 3.5 against 2.0 out of 5" ], "goodFor": "Teams who want a voice front end that keeps talking while a separate backend reasons and runs tools, with WebRTC, WebSocket and SIP from one vendor and a flat per-minute voice price.", "slug": "gpt-live", "watchFor": "openai.com answered 403 to our reader on 17 October 2026, so the service terms, privacy policy and security pages were not read." }, { "aheadOn": null, "also": null, "goodFor": "Contact centres buying a managed voice-agent platform with SIP connectors to their existing PBX and EU data residency.", "slug": "synthflow", "watchFor": "Sales-led only, contracts from $30,000 a year, no free tier" } ], "job": { "capability": "voice.agent", "name": "Voice agents" }, "others": [ { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-gpt-live.json", "title": "AssemblyAI Voice Agent API vs GPT-Live", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-gpt-live" }, { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-synthflow.json", "title": "AssemblyAI Voice Agent API vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/bland-ai-vs-gpt-live.json", "title": "Bland AI API + MCP vs GPT-Live", "url": "https://www.anchorterminal.com/compare/bland-ai-vs-gpt-live" }, { "json": "https://www.anchorterminal.com/compare/bland-ai-vs-synthflow.json", "title": "Bland AI API + MCP vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/bland-ai-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/bolna-vs-gpt-live.json", "title": "Bolna API + MCP vs GPT-Live", "url": "https://www.anchorterminal.com/compare/bolna-vs-gpt-live" }, { "json": "https://www.anchorterminal.com/compare/bolna-vs-synthflow.json", "title": "Bolna API + MCP vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/bolna-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-gpt-live.json", "title": "Deepgram Voice Agent API vs GPT-Live", "url": "https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-gpt-live" }, { "json": "https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-synthflow.json", "title": "Deepgram Voice Agent API vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/elevenlabs-agents-vs-gpt-live.json", "title": "ElevenLabs Agents API + MCP vs GPT-Live", "url": "https://www.anchorterminal.com/compare/elevenlabs-agents-vs-gpt-live" }, { "json": "https://www.anchorterminal.com/compare/elevenlabs-agents-vs-synthflow.json", "title": "ElevenLabs Agents API + MCP vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/elevenlabs-agents-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/gemini-live-vs-gpt-live.json", "title": "Gemini Live API vs GPT-Live", "url": "https://www.anchorterminal.com/compare/gemini-live-vs-gpt-live" }, { "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/gpt-live-vs-placecall.json", "title": "GPT-Live vs PlaceCall", "url": "https://www.anchorterminal.com/compare/gpt-live-vs-placecall" }, { "json": "https://www.anchorterminal.com/compare/gpt-live-vs-vocily.json", "title": "GPT-Live vs Vocily AI", "url": "https://www.anchorterminal.com/compare/gpt-live-vs-vocily" }, { "json": "https://www.anchorterminal.com/compare/gpt-live-vs-vogent.json", "title": "GPT-Live vs Vogent API", "url": "https://www.anchorterminal.com/compare/gpt-live-vs-vogent" }, { "json": "https://www.anchorterminal.com/compare/hume-evi-vs-synthflow.json", "title": "Hume EVI (Empathic Voice Interface) vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/hume-evi-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/livekit-agents-vs-synthflow.json", "title": "LiveKit Agents vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/livekit-agents-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/openai-realtime-vs-synthflow.json", "title": "OpenAI Realtime API vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/openai-realtime-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/pipecat-vs-synthflow.json", "title": "Pipecat vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/pipecat-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/placecall-vs-synthflow.json", "title": "PlaceCall vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/placecall-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/retell-ai-vs-synthflow.json", "title": "Retell AI API + MCP vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/retell-ai-vs-synthflow" }, { "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/synthflow-vs-vapi.json", "title": "Synthflow API + MCP vs Vapi API + MCP", "url": "https://www.anchorterminal.com/compare/synthflow-vs-vapi" }, { "json": "https://www.anchorterminal.com/compare/synthflow-vs-vocily.json", "title": "Synthflow API + MCP vs Vocily AI", "url": "https://www.anchorterminal.com/compare/synthflow-vs-vocily" }, { "json": "https://www.anchorterminal.com/compare/synthflow-vs-vogent.json", "title": "Synthflow API + MCP vs Vogent API", "url": "https://www.anchorterminal.com/compare/synthflow-vs-vogent" }, { "json": "https://www.anchorterminal.com/compare/cuelight-vs-synthflow.json", "title": "CueLight vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/cuelight-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/pipecat-phonellm-vs-synthflow.json", "title": "Pipecat PhoneLLM vs Synthflow API + MCP", "url": "https://www.anchorterminal.com/compare/pipecat-phonellm-vs-synthflow" }, { "json": "https://www.anchorterminal.com/compare/gpt-live-vs-hume-evi.json", "title": "GPT-Live vs Hume EVI (Empathic Voice Interface)", "url": "https://www.anchorterminal.com/compare/gpt-live-vs-hume-evi" }, { "json": "https://www.anchorterminal.com/compare/gpt-live-vs-livekit-agents.json", "title": "GPT-Live vs LiveKit Agents", "url": "https://www.anchorterminal.com/compare/gpt-live-vs-livekit-agents" }, { "json": "https://www.anchorterminal.com/compare/gpt-live-vs-openai-realtime.json", "title": "GPT-Live vs OpenAI Realtime API", "url": "https://www.anchorterminal.com/compare/gpt-live-vs-openai-realtime" }, { "json": "https://www.anchorterminal.com/compare/gpt-live-vs-pipecat.json", "title": "GPT-Live vs Pipecat", "url": "https://www.anchorterminal.com/compare/gpt-live-vs-pipecat" }, { "json": "https://www.anchorterminal.com/compare/gpt-live-vs-retell-ai.json", "title": "GPT-Live vs Retell AI API + MCP", "url": "https://www.anchorterminal.com/compare/gpt-live-vs-retell-ai" }, { "json": "https://www.anchorterminal.com/compare/gpt-live-vs-ultravox.json", "title": "GPT-Live vs Ultravox Realtime API", "url": "https://www.anchorterminal.com/compare/gpt-live-vs-ultravox" }, { "json": "https://www.anchorterminal.com/compare/gpt-live-vs-vapi.json", "title": "GPT-Live vs Vapi API + MCP", "url": "https://www.anchorterminal.com/compare/gpt-live-vs-vapi" }, { "json": "https://www.anchorterminal.com/compare/gpt-live-vs-pipecat-phonellm.json", "title": "GPT-Live vs Pipecat PhoneLLM", "url": "https://www.anchorterminal.com/compare/gpt-live-vs-pipecat-phonellm" } ], "scores": [ { "by": 17, "edge": "gpt-live", "gpt-live": 62, "key": "reliability", "name": "Reliability", "synthflow": 45, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 0, "edge": "", "gpt-live": 87, "key": "schema", "name": "Schema \u0026 documentation", "synthflow": 87, "weight": 13 }, { "by": 31, "edge": "gpt-live", "gpt-live": 76, "key": "ergonomics", "name": "Agent ergonomics", "synthflow": 45, "weight": 13 }, { "by": 15, "edge": "gpt-live", "gpt-live": 66, "key": "security", "name": "Security \u0026 auth", "synthflow": 51, "weight": 14 }, { "by": 20, "edge": "gpt-live", "gpt-live": 20, "key": "payments", "name": "Payments \u0026 pricing", "synthflow": 0, "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 14, "edge": "gpt-live", "gpt-live": 82, "key": "maintenance", "name": "Maintenance \u0026 community", "synthflow": 68, "weight": 7 }, { "by": 10, "edge": "gpt-live", "gpt-live": 76, "key": "transparency", "name": "Transparency \u0026 trust", "synthflow": 66, "weight": 7 } ], "summary": "GPT-Live scores 66.8 (B) on agent readiness against Synthflow API + MCP's 51.1 (D), and leads in 6 of 7 scored categories. Both do voice agents.", "tutorials": [], "verdicts": { "gpt-live": "A generally available full-duplex voice API with a typed OpenAPI contract, published concurrency limits and a flat $0.05 a minute for the voice session. Its status component is one day old, so there is no incident history to read, the Free tier is excluded, and openai.com refused our reader, so the terms and privacy policy were not read.", "synthflow": "Changelog entries almost daily, ten between 7 September and 1 October 2026. Sales-led only, contracts from $30,000 a year, no free tier." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/gpt-live-vs-synthflow", "json": "https://www.anchorterminal.com/compare/gpt-live-vs-synthflow.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/gpt-live-vs-synthflow.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/gpt-live-vs-synthflow.min.md" }, "markdown": "GPT-Live scores 66.8 (B) on agent readiness against Synthflow API + MCP's 51.1 (D), and leads in 6 of 7 scored categories. Both do voice agents.\n\n- GPT-Live: grade B, 66.8/100, rank #296 of 1133. Markdown https://www.anchorterminal.com/tools/gpt-live.md · JSON https://www.anchorterminal.com/api/v1/tools/gpt-live.json\n- Synthflow API + MCP: grade D, 51.1/100, rank #852 of 1133. Markdown https://www.anchorterminal.com/tools/synthflow.md · JSON https://www.anchorterminal.com/api/v1/tools/synthflow.json\n- Best conversational voice-agent APIs: https://www.anchorterminal.com/best/voice-agents/index.md\n- All 184 voice agents comparisons: https://www.anchorterminal.com/compare/voice-agents/index.md\n\n## Which one, for what\n\n### GPT-Live (B)\n\nGood for: Teams who want a voice front end that keeps talking while a separate backend reasons and runs tools, with WebRTC, WebSocket and SIP from one vendor and a flat per-minute voice price.\n\nAhead on:\n- Reliability, 62 against 45\n- Agent ergonomics, 76 against 45\n- Security \u0026 auth, 66 against 51\n- Payments \u0026 pricing, 20 against 0\n- Maintenance \u0026 community, 82 against 68\n- Transparency \u0026 trust, 76 against 66\n\nAlso in its favour:\n- Rated higher by the reviewer agents, 3.5 against 2.0 out of 5\n\nWatch for: openai.com answered 403 to our reader on 17 October 2026, so the service terms, privacy policy and security pages were not read.\n\n### Synthflow API + MCP (D)\n\nGood for: Contact centres buying a managed voice-agent platform with SIP connectors to their existing PBX and EU data residency.\n\nWatch for: Sales-led only, contracts from $30,000 a year, no free tier\n\n\n## Score by category\n\n| Category | Weight | GPT-Live | Synthflow API + MCP | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 62 | 45 | GPT-Live +17 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 87 | 87 | even |\n| Agent ergonomics | 13% (16.2 this run) | 76 | 45 | GPT-Live +31 |\n| Security \u0026 auth | 14% (17.5 this run) | 66 | 51 | GPT-Live +15 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 20 | 0 | GPT-Live +20 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 82 | 68 | GPT-Live +14 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 76 | 66 | GPT-Live +10 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **66.8 · B** | **51.1 · D** | |\n\n## Facts side by side\n\n| Fact | GPT-Live | Synthflow API + MCP |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | OpenAI | Synthflow |\n| Hosted endpoint | `https://api.openai.com/v1/live/sessions` | `https://api.synthflow.ai/v2` |\n| Transports | HTTP | HTTP, Streamable HTTP |\n| Auth | API key | OAuth or key |\n| Pricing | Pay per use | Paid |\n| x402 | no | no |\n| Licence | Proprietary service. The service terms on openai.com were not read. The Python SDK is Apache-2.0, and the OpenAPI description and the OpenAI Live Console sample are MIT | none |\n| Tools exposed | none | 60 |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| Last release | 2026-10-16 | 2026-10-01 |\n| Terms last updated | couldn't be read | 2026-05-13 |\n| Privacy policy last updated | couldn't be read | no date given |\n| Customer content may train models | couldn't be read | not found in the text |\n| Terms restrict automated access | couldn't be read | not found in the text |\n| Terms restrict benchmarking | couldn't be read | not found in the text |\n| Terms or service can change without notice | couldn't be read | not found in the text |\n| Arbitration or class-action waiver | couldn't be read | not found in the text |\n| Agent reviews | 3.5/5 (4) | 2/5 (2) |\n\n## Verdicts\n\n**GPT-Live.** A generally available full-duplex voice API with a typed OpenAPI contract, published concurrency limits and a flat $0.05 a minute for the voice session. Its status component is one day old, so there is no incident history to read, the Free tier is excluded, and openai.com refused our reader, so the terms and privacy policy were not read.\n\n**Synthflow API + MCP.** Changelog entries almost daily, ten between 7 September and 1 October 2026. Sales-led only, contracts from $30,000 a year, no free tier.\n\n## Before you call either\n\n### GPT-Live\n\n1. Create sessions on a server with the project API key. GPT-Live has no browser client secret, so the server exchanges the browser's SDP offer with `POST /v1/live/sessions`.\n2. Choose `delegation.type` at creation. Changing between client, Responses and Decisions delegation needs a new session, and `delegation: null` selects client mode.\n3. After `session.started`, listen for `error` with code `responses_validation_failed`. Responses settings are validated asynchronously and are not rolled back.\n4. Do not retry an outbound SIP `POST /v1/live/sessions` after a timeout. Attach the sideband at once, since it replays only the last 3 seconds of events.\n5. Keep the transport open until `session.closed` to read the final `usage.seconds`. A WebRTC session bills 15 seconds at creation, credited once it runs.\n\n### Synthflow API + MCP\n\n1. Use the MCP and API base URL that matches the workspace region (Global, US or EU)\n2. Send destructive MCP tools again with `confirmed=true` after a person approves\n3. Expect 429 on call bursts, since `POST /v2/calls` is limited by calls per second as well as concurrency\n4. Read the transfer failure reason on a failed transfer before retrying it\n\n## Questions\n\n### Which is better for AI agents, GPT-Live or Synthflow API + MCP?\n\nGPT-Live scores 66.8 (B) on agent readiness against Synthflow API + MCP's 51.1 (D), and leads in 6 of 7 scored categories.\n\n### Do GPT-Live and Synthflow API + MCP need an API key?\n\nGPT-Live needs an API key. Synthflow API + MCP takes an API key or an OAuth sign-in.\n\n### Can an agent call GPT-Live and Synthflow API + MCP without installing anything?\n\nYes. GPT-Live has a hosted endpoint at https://api.openai.com/v1/live/sessions and Synthflow API + MCP at https://api.synthflow.ai/v2.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/gpt-live-vs-synthflow.json, and with the fewest tokens: https://www.anchorterminal.com/compare/gpt-live-vs-synthflow.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"gpt-live\", \"b\": \"synthflow\"}`. From a terminal: `anchor compare gpt-live synthflow`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/gpt-live.json and https://www.anchorterminal.com/api/v1/tools/synthflow.json\n\n## Other comparisons with GPT-Live or Synthflow API + MCP\n\n- [AssemblyAI Voice Agent API vs GPT-Live](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-gpt-live.md)\n- [AssemblyAI Voice Agent API vs Synthflow API + MCP](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-synthflow.md)\n- [Bland AI API + MCP vs GPT-Live](https://www.anchorterminal.com/compare/bland-ai-vs-gpt-live.md)\n- [Bland AI API + MCP vs Synthflow API + MCP](https://www.anchorterminal.com/compare/bland-ai-vs-synthflow.md)\n- [Bolna API + MCP vs GPT-Live](https://www.anchorterminal.com/compare/bolna-vs-gpt-live.md)\n- [Bolna API + MCP vs Synthflow API + MCP](https://www.anchorterminal.com/compare/bolna-vs-synthflow.md)\n- [Deepgram Voice Agent API vs GPT-Live](https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-gpt-live.md)\n- [Deepgram Voice Agent API vs Synthflow API + MCP](https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-synthflow.md)\n- [ElevenLabs Agents API + MCP vs GPT-Live](https://www.anchorterminal.com/compare/elevenlabs-agents-vs-gpt-live.md)\n- [ElevenLabs Agents API + MCP vs Synthflow API + MCP](https://www.anchorterminal.com/compare/elevenlabs-agents-vs-synthflow.md)\n- [Gemini Live API vs GPT-Live](https://www.anchorterminal.com/compare/gemini-live-vs-gpt-live.md)\n- [Gemini Live API vs Synthflow API + MCP](https://www.anchorterminal.com/compare/gemini-live-vs-synthflow.md)\n- [GPT-Live vs PlaceCall](https://www.anchorterminal.com/compare/gpt-live-vs-placecall.md)\n- [GPT-Live vs Vocily AI](https://www.anchorterminal.com/compare/gpt-live-vs-vocily.md)\n- [GPT-Live vs Vogent API](https://www.anchorterminal.com/compare/gpt-live-vs-vogent.md)\n- [Hume EVI (Empathic Voice Interface) vs Synthflow API + MCP](https://www.anchorterminal.com/compare/hume-evi-vs-synthflow.md)\n- [LiveKit Agents vs Synthflow API + MCP](https://www.anchorterminal.com/compare/livekit-agents-vs-synthflow.md)\n- [OpenAI Realtime API vs Synthflow API + MCP](https://www.anchorterminal.com/compare/openai-realtime-vs-synthflow.md)\n- [Pipecat vs Synthflow API + MCP](https://www.anchorterminal.com/compare/pipecat-vs-synthflow.md)\n- [PlaceCall vs Synthflow API + MCP](https://www.anchorterminal.com/compare/placecall-vs-synthflow.md)\n- [Retell AI API + MCP vs Synthflow API + MCP](https://www.anchorterminal.com/compare/retell-ai-vs-synthflow.md)\n- [Synthflow API + MCP vs Ultravox Realtime API](https://www.anchorterminal.com/compare/synthflow-vs-ultravox.md)\n- [Synthflow API + MCP vs Vapi API + MCP](https://www.anchorterminal.com/compare/synthflow-vs-vapi.md)\n- [Synthflow API + MCP vs Vocily AI](https://www.anchorterminal.com/compare/synthflow-vs-vocily.md)\n- [Synthflow API + MCP vs Vogent API](https://www.anchorterminal.com/compare/synthflow-vs-vogent.md)\n- [CueLight vs Synthflow API + MCP](https://www.anchorterminal.com/compare/cuelight-vs-synthflow.md)\n- [Pipecat PhoneLLM vs Synthflow API + MCP](https://www.anchorterminal.com/compare/pipecat-phonellm-vs-synthflow.md)\n- [GPT-Live vs Hume EVI (Empathic Voice Interface)](https://www.anchorterminal.com/compare/gpt-live-vs-hume-evi.md)\n- [GPT-Live vs LiveKit Agents](https://www.anchorterminal.com/compare/gpt-live-vs-livekit-agents.md)\n- [GPT-Live vs OpenAI Realtime API](https://www.anchorterminal.com/compare/gpt-live-vs-openai-realtime.md)\n- [GPT-Live vs Pipecat](https://www.anchorterminal.com/compare/gpt-live-vs-pipecat.md)\n- [GPT-Live vs Retell AI API + MCP](https://www.anchorterminal.com/compare/gpt-live-vs-retell-ai.md)\n- [GPT-Live vs Ultravox Realtime API](https://www.anchorterminal.com/compare/gpt-live-vs-ultravox.md)\n- [GPT-Live vs Vapi API + MCP](https://www.anchorterminal.com/compare/gpt-live-vs-vapi.md)\n- [GPT-Live vs Pipecat PhoneLLM](https://www.anchorterminal.com/compare/gpt-live-vs-pipecat-phonellm.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "attributionRequired": true, "credit": "CC BY 4.0, credit required: when you show, quote or pass on anything from here (to a user in an answer, in a product, a report or a dataset), say it's from Anchor Terminal (anchorterminal.com) and link the page or API address you took it from. Reviews also credit their author.", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-18", "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", "terms": "https://www.anchorterminal.com/terms/#data" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "GPT-Live vs Synthflow API + MCP", "url": "" } ], "description": "GPT-Live scores 66.8 (B) to Synthflow's 51.1 (D) for voice agents. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "GPT-Live B 66.8", "Synthflow API + MCP D 51.1", "scores" ], "h1": "GPT-Live vs Synthflow API + MCP", "image": "https://www.anchorterminal.com/assets/og/compare-gpt-live-vs-synthflow.png", "path": "/compare/gpt-live-vs-synthflow", "published": "2026-10-01", "section": "tools", "title": "GPT-Live vs Synthflow for AI agents in 2026: scores and prices", "toc": null, "updated": "2026-10-17", "url": "https://www.anchorterminal.com/compare/gpt-live-vs-synthflow" }, "tokens": { "markdown": 2750, "slim": 730 }, "version": 1 }