{ "data": { "a": { "slug": "assemblyai-voice-agent", "name": "AssemblyAI Voice Agent API", "vendor": "AssemblyAI, Inc.", "vendorUrl": "https://www.assemblyai.com", "kind": "http-api", "category": "voice-agents", "summary": "AssemblyAI's Voice Agent API runs a spoken conversation over one WebSocket, combining its own speech-to-text, language model and text-to-speech. Agents are stored through a REST API and reached from a browser, a server or an inbound Twilio SIP number.", "url": "https://www.anchorterminal.com/tools/assemblyai-voice-agent", "markdownUrl": "https://www.anchorterminal.com/tools/assemblyai-voice-agent.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/assemblyai-voice-agent.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/assemblyai-voice-agent.json", "repo": "https://github.com/AssemblyAI/voice-agent-starter-python", "license": "Proprietary service under AssemblyAI's Terms of Service. The two starter repositories on GitHub carry no licence file", "transports": [ "http" ], "remoteUrl": "wss://agents.assemblyai.com/v1/ws", "packages": [], "auth": "api-key", "authNotes": "Self-serve API key from the dashboard, sent in the `Authorization` header on REST calls and on the WebSocket upgrade, with or without a `Bearer` prefix. Keys belong to a project and can be created and deleted in the dashboard (2 on the free plan, 4 on pay as you go, 25 on a contract). No scopes or expiry were found. Browser clients use a one-time token from `GET /v1/token`, redeemable within 1 to 600 seconds and passed as the `token` query parameter.", "pricing": "usage", "pricingNotes": "$4.50 an hour ($0.075 a minute), billed per second from socket open to session end, idle time included. The rate covers speech-to-text, the managed model, speech output, recordings and hosting. New accounts get $50 of credit with no card, which covers the Voice Agent API. LLM Gateway tokens and Twilio carrier minutes are billed separately. Volume pricing is by sales contact (https://www.assemblyai.com/pricing, https://www.assemblyai.com/docs/billing-and-pricing, checked 2026-10-09).", "priceSummary": "Pay per use", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the Voice Agent docs, the two API description files, the billing docs or the pricing page. Payment is by card into a prepaid balance (checked 2026-10-09).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-10-09" }, "docsUrl": "https://www.assemblyai.com/docs/voice-agents/voice-agent-api", "llmsTxt": "https://www.assemblyai.com/docs/llms.txt", "openapi": "https://www.assemblyai.com/docs/api-reference/specs/voice-agent-api.yaml", "capabilities": [ "voice.agent", "voice.pipeline", "voice.tools", "voice.telephony" ], "tags": [ "hosted", "no-card", "closed-source", "llms-txt", "webhooks", "streaming", "pipeline", "python", "javascript", "status-page", "soc2" ], "lastRelease": "2026-08-26", "graded": true, "anchor": { "graded": true, "score": 64.4, "grade": "B", "agentReady": false, "rank": 351, "ranked": true, "rankOf": 950, "categoryRank": 4, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 72, "maintenance": 64, "payments": 40, "reliability": 60, "schema": 83, "security": 62, "transparency": 66 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-09" }, "negative": 0, "verdict": "One $0.075 a minute rate covers speech-to-text, the managed model, speech output, recordings and hosting, and the socket has an AsyncAPI file, typed error codes and a 30-second resume window. No concurrent-session limit is published, the status page has no Voice Agent component, and phone calls are inbound only through a Twilio trunk the customer owns.", "bestFor": "A developer who wants one managed pipeline at a flat rate and is content with AssemblyAI's own speech models and voices, with an optional model of their own.", "strengths": [ "One published rate of $4.50 an hour ($0.075 a minute), billed per second, with $50 of credit and no card for new accounts", "AsyncAPI 3.0 file for the socket, an OpenAPI file for the token endpoint, llms.txt and a Markdown copy of every docs page", "Session errors carry a code, a message and sometimes the offending field, and the docs name the three codes that are safe to retry", "HTTP tool header values are write-only and encrypted at rest, and tool calls are limited to public `https` hosts with redirects refused", "Every session is stored with a stereo recording, a JSON timeline of turns and tool calls, and signed webhooks with a delivery history" ], "weaknesses": [ "No number is published for the concurrent-session limit that the `concurrency_exceeded` error enforces", "status.assemblyai.com lists the Asynchronous API, Streaming API and LLM Gateway, with no Voice Agent component", "Telephony is inbound only, over a SIP trunk on a Twilio account the customer owns", "API keys have no scopes or expiry, and opting out of model training needs a paid plan", "The Terms of Service bar benchmarking and competitive analysis (2.4(f)) and any automated or programmatic method of extracting data or Output (4.4), which matters before any probe is run" ], "agentNotes": [ "Send `session.end` before closing the socket. Without it the session stays resumable, and billed, for 30 seconds", "Retry only `at_capacity`, `concurrency_exceeded` and `internal_error`, with backoff. Every other session error code is fatal", "Send `tool.result` inside the `reply.done` handler, not straight after `tool.call`", "Mint a one-time token with `GET /v1/token` for browser clients and never ship the API key to a page", "Deduplicate webhooks on `event_id`, and verify `X-AAI-Signature` against the raw body bytes because a 401 is not retried" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "B", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 64.4 } ], "editorialScores": { "ergonomics": 72, "maintenance": 64, "payments": 40, "reliability": 60, "schema": 83, "security": 62, "transparency": 51 }, "provenanceScore": 81 }, "connect": { "install": "git clone https://github.com/AssemblyAI/voice-agent-starter-python", "http": "curl -X POST https://agents.assemblyai.com/v1/agents \\\n -H \"Authorization: $ASSEMBLYAI_API_KEY\" \\\n -H \"Content-Type: application/json\" \\\n -d '{\"name\": \"Support Assistant\", \"system_prompt\": \"You are a friendly support agent.\", \"greeting\": \"Hi, how can I help?\", \"voice\": {\"voice_id\": \"alba\"}}'", "claudeCode": "claude mcp add --transport http --scope user assemblyai-docs https://mcp.assemblyai.com/docs" }, "letme": { "capability": "https://letme.dev/voice.agent", "tool": "https://letme.dev/assemblyai-voice-agent" }, "sameCompany": [ "assemblyai-stt" ], "area": "voice", "unitPrices": [ { "item": "Voice Agent session", "unit": "call-minute", "usd": 0.075, "note": "$4.50 an hour billed per second of open socket. Speech-to-text, managed model, speech output and recordings included. LLM Gateway tokens and carrier minutes extra" } ], "provenance": { "legalEntity": "AssemblyAI, Inc.", "domain": "assemblyai.com", "domainRegistered": "2016-12-24", "endpointOnVendorDomain": true, "terms": "https://www.assemblyai.com/legal/terms-of-service", "privacy": "https://www.assemblyai.com/legal/privacy-policy", "statusPage": "https://status.assemblyai.com", "changelog": "https://www.assemblyai.com/changelog", "securityTxt": "unknown", "checked": "2026-10-09", "score": 81 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/assemblyai-voice-agent.json", "live": { "slug": "assemblyai-voice-agent", "probe": { "target": "wss://agents.assemblyai.com/v1/ws", "method": "get", "lastAt": "2026-10-10T02:54:46.844166109Z", "lastOk": false, "lastStatus": 0, "lastMs": 0, "lastNote": "unsupported protocol scheme \"wss\"", "authRequired": false, "uptime24h": 0, "uptime30d": 0, "p50ms24h": 0, "p95ms24h": 0, "samples24h": 115, "samples30d": 115, "days": [ { "date": "2026-10-09", "probes": 85, "ok": 0 }, { "date": "2026-10-10", "probes": 30, "ok": 0 } ], "outages": [ { "start": "2026-10-09T15:42:56.660671906Z", "end": "0001-01-01T00:00:00Z", "note": "unsupported protocol scheme \"wss\"" } ] }, "vendorStatus": { "page": "https://status.assemblyai.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-10T02:49:55.908212561Z" }, "githubStars": 3, "pages": [ { "url": "https://www.assemblyai.com/docs/billing-and-pricing", "kind": "pricing", "status": 200, "checkedAt": "2026-10-09T18:48:16.435584974Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "3b80ad9644cf" } ], "updatedAt": "2026-10-10T02:54:46.844166109Z" } }, "answer": "AssemblyAI Voice Agent API scores 64.4 (B) on agent readiness against Vogent API's 47.1 (D), and leads in 6 of 7 scored categories.", "b": { "slug": "vogent", "name": "Vogent API", "vendor": "Vogent", "vendorUrl": "https://www.vogent.ai", "kind": "http-api", "category": "voice-agents", "summary": "Phone voice-agent platform with its own conversational LLM, voices and IVR-navigation models alongside GPT.", "url": "https://www.anchorterminal.com/tools/vogent", "markdownUrl": "https://www.anchorterminal.com/tools/vogent.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/vogent.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/vogent.json", "transports": [ "http" ], "remoteUrl": "https://api.vogent.ai/api", "packages": [ { "registry": "npm", "name": "@vogent/vogent-web-client" } ], "auth": "api-key", "authNotes": "Bearer API key created per user in the dashboard. Keys stop working when that user leaves the workspace. Webhooks are signed with HMAC-SHA256 in the `X-Elto-Signature` header.", "pricing": "usage", "pricingNotes": "Pay as you go, metered by the second. $0.09 a minute ($0.0015 a second) with standard voices and $0.14 a minute ($0.0023 a second) with premium voices. The docs don't say whether telephony is included or whether there's free credit. Enterprise plans add volume discounts from about 5,000 to 10,000 calls a month (https://docs.vogent.ai/platform-overview/billing).", "priceSummary": "Pay per use", "where": "hosted", "x402": { "level": "no", "evidence": "No x402 support in the docs or OpenAPI spec (checked 2026-09-30).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": 899, "pypiWeekly": null, "asOf": "2026-09-30" }, "docsUrl": "https://docs.vogent.ai", "llmsTxt": "https://docs.vogent.ai/llms.txt", "openapi": "https://docs.vogent.ai/api-reference/openapi.yaml", "capabilities": [ "voice.agent", "voice.pipeline", "voice.tools", "voice.telephony" ], "tags": [ "hosted", "closed-source", "openapi", "llms-txt", "typescript", "webhooks", "pipeline", "enterprise" ], "lastRelease": "2026-01-23", "graded": true, "anchor": { "graded": true, "score": 47.1, "grade": "D", "agentReady": false, "rank": 838, "ranked": true, "rankOf": 950, "categoryRank": 14, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 57, "maintenance": 11, "payments": 15, "reliability": 62, "schema": 73, "security": 40, "transparency": 43 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "IVR detection and navigation models for outbound calls. No public changelog and no release found since January 2026.", "bestFor": "Outbound calling that has to navigate IVRs in English or Spanish, in the US, Canada and the UK.", "strengths": [ "IVR detection and navigation models for outbound calls", "Idempotent dial creation with `idempotencyKey` and a 409 on reuse", "OpenAPI 3.0.3 and AsyncAPI files", "HMAC-SHA256 signed webhooks", "Per-second billing, $0.09 a minute on standard voices" ], "weaknesses": [ "No public changelog and no release found since January 2026", "No published rate limits or 429 handling", "No free tier or trial stated", "Terms date from March 2024, with no retention, subprocessor or certification statements", "No MCP server" ], "agentNotes": [ "Send an `idempotencyKey` on `POST /dials`, a reused key returns 409", "Create a call with `callAgentId`, plus `toNumber` and `fromNumberId` for phone calls", "Tell the model when to emit `\u003c|transfer|\u003e`, since transfers fire on that tag", "Verify webhooks with the HMAC in `X-Elto-Signature`", "Expect new dials to fail at the workspace's concurrent dial limit until calls end" ], "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": 47.1 } ], "editorialScores": { "ergonomics": 57, "maintenance": 11, "payments": 15, "reliability": 62, "schema": 73, "security": 40, "transparency": 20 }, "provenanceScore": 66 }, "connect": { "http": "curl -X POST https://api.vogent.ai/api/dials -H \"Authorization: Bearer $VOGENT_API_KEY\" \\\n -H \"Content-Type: application/json\" \\\n -d '{\"callAgentId\":\"\u003cagent-id\u003e\",\"toNumber\":\"+11234567890\",\"fromNumberId\":\"\u003cnumber-id\u003e\"}'" }, "letme": { "capability": "https://letme.dev/voice.agent", "tool": "https://letme.dev/vogent" }, "area": "voice", "unitPrices": [ { "item": "Standard voices", "unit": "call-minute", "usd": 0.09, "note": "billed per second, docs don't say if telephony is included" }, { "item": "Premium voices", "unit": "call-minute", "usd": 0.14, "note": "billed per second" } ], "provenance": { "legalEntity": "Monoid, Inc.", "domain": "vogent.ai", "domainRegistered": "2024-08-28", "domainNote": "Vogent traded as Elto before, and recording URLs still sit on api.getelto.com.", "endpointOnVendorDomain": true, "terms": "https://www.vogent.ai/terms", "privacy": "https://www.vogent.ai/privacy", "statusPage": "https://status.vogent.ai", "changelog": "", "securityTxt": "none", "checked": "2026-09-30", "notes": [ "The terms and privacy notice name Monoid, Inc., doing business as Vogent, and were last updated 2024-03-03. Both pages render only with JavaScript." ], "score": 66 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/vogent.json", "live": { "slug": "vogent", "probe": { "target": "https://api.vogent.ai/api", "method": "get", "lastAt": "2026-10-10T02:55:15.415215033Z", "lastOk": true, "lastStatus": 404, "lastMs": 349, "authRequired": false, "uptime24h": 100, "uptime30d": 99.96, "p50ms24h": 340, "p95ms24h": 420, "samples24h": 249, "samples30d": 2466, "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": 271 }, { "date": "2026-10-08", "probes": 268, "ok": 268 }, { "date": "2026-10-09", "probes": 250, "ok": 250 }, { "date": "2026-10-10", "probes": 30, "ok": 30 } ] }, "vendorStatus": { "page": "https://status.vogent.ai", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-10-10T00:51:24.122715626Z" }, "versions": [ { "registry": "npm", "name": "@vogent/vogent-web-client", "version": "0.1.7", "seenAt": "2026-10-09T17:27:34.269375345Z" } ], "npmWeekly": 830, "securityTxt": { "url": "https://vogent.ai/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-09T15:40:20.330672003Z" }, "llmsTxt": { "url": "https://docs.vogent.ai/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-09T14:02:59.216793572Z" }, "domain": { "domain": "vogent.ai", "registered": "2024-08-28", "source": "https://rdap.identitydigital.services/rdap/domain/vogent.ai", "checkedAt": "2026-10-04T13:04:21.882731766Z" }, "pages": [ { "url": "https://www.vogent.ai/privacy", "kind": "privacy", "status": 304, "checkedAt": "2026-10-09T18:55:28.410583935Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "5257817e1996" }, { "url": "https://www.vogent.ai/terms", "kind": "terms", "status": 304, "checkedAt": "2026-10-09T18:55:30.577500296Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "5257817e1996" } ], "updatedAt": "2026-10-10T02:55:15.415215033Z" } }, "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "AssemblyAI, Inc.", "b": "Vogent", "name": "Vendor" }, { "a": "wss://agents.assemblyai.com/v1/ws", "b": "https://api.vogent.ai/api", "name": "Hosted endpoint" }, { "a": "HTTP", "b": "HTTP", "name": "Transports" }, { "a": "API key", "b": "API key", "name": "Auth" }, { "a": "Pay per use", "b": "Pay per use", "name": "Pricing" }, { "a": "$0.075 per minute of call", "b": "not published", "name": "Price for voice agents" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "Proprietary service under AssemblyAI's Terms of Service. The two starter repositories on GitHub carry no licence file", "b": "none", "name": "Licence" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "2026-08-26", "b": "2026-01-23", "name": "Last release" }, { "a": "2026-07-01", "b": "couldn't be read", "name": "Terms last updated" }, { "a": "2026-05-26", "b": "couldn't be read", "name": "Privacy policy last updated" }, { "a": "yes, with an opt-out", "b": "couldn't be read", "name": "Customer content may train models" }, { "a": "yes", "b": "couldn't be read", "name": "Terms restrict automated access" }, { "a": "yes", "b": "couldn't be read", "name": "Terms restrict benchmarking" }, { "a": "not found in the text", "b": "couldn't be read", "name": "Terms or service can change without notice" }, { "a": "not found in the text", "b": "couldn't be read", "name": "Arbitration or class-action waiver" }, { "a": "none", "b": "899 npm/wk", "name": "Popularity" }, { "a": "none", "b": "2/5 (2)", "name": "Agent reviews" } ], "faq": [ { "answer": "AssemblyAI Voice Agent API scores 64.4 (B) on agent readiness against Vogent API's 47.1 (D), and leads in 6 of 7 scored categories.", "question": "Which is better for AI agents, AssemblyAI Voice Agent API or Vogent API?" }, { "answer": "Both need an API key.", "question": "Do AssemblyAI Voice Agent API and Vogent API need an API key?" }, { "answer": "Yes. AssemblyAI Voice Agent API has a hosted endpoint at wss://agents.assemblyai.com/v1/ws and Vogent API at https://api.vogent.ai/api.", "question": "Can an agent call AssemblyAI Voice Agent API and Vogent API without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Schema \u0026 documentation, 83 against 73", "Agent ergonomics, 72 against 57", "Security \u0026 auth, 62 against 40", "Payments \u0026 pricing, 40 against 15", "Maintenance \u0026 community, 64 against 11", "Transparency \u0026 trust, 66 against 43" ], "also": [ "Free to start without a card" ], "goodFor": "A developer who wants one managed pipeline at a flat rate and is content with AssemblyAI's own speech models and voices, with an optional model of their own.", "slug": "assemblyai-voice-agent", "watchFor": "No number is published for the concurrent-session limit that the `concurrency_exceeded` error enforces" }, { "aheadOn": null, "also": null, "goodFor": "Outbound calling that has to navigate IVRs in English or Spanish, in the US, Canada and the UK.", "slug": "vogent", "watchFor": "No public changelog and no release found since January 2026" } ], "job": { "capability": "voice.agent", "name": "Voice agents" }, "others": [ { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-bland-ai.json", "title": "AssemblyAI Voice Agent API vs Bland AI API + MCP", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-bland-ai" }, { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-bolna.json", "title": "AssemblyAI Voice Agent API vs Bolna API + MCP", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-bolna" }, { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-deepgram-voice-agent.json", "title": "AssemblyAI Voice Agent API vs Deepgram Voice Agent API", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-deepgram-voice-agent" }, { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-elevenlabs-agents.json", "title": "AssemblyAI Voice Agent API vs ElevenLabs Agents API + MCP", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-elevenlabs-agents" }, { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-gemini-live.json", "title": "AssemblyAI Voice Agent API vs Gemini Live API", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-gemini-live" }, { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-hume-evi.json", "title": "AssemblyAI Voice Agent API vs Hume EVI (Empathic Voice Interface)", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-hume-evi" }, { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-openai-realtime.json", "title": "AssemblyAI Voice Agent API vs OpenAI Realtime API", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-openai-realtime" }, { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-retell-ai.json", "title": "AssemblyAI Voice Agent API vs Retell AI API + MCP", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-retell-ai" }, { "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/assemblyai-voice-agent-vs-ultravox.json", "title": "AssemblyAI Voice Agent API vs Ultravox Realtime API", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-ultravox" }, { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vapi.json", "title": "AssemblyAI Voice Agent API vs Vapi API + MCP", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vapi" }, { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vocily.json", "title": "AssemblyAI Voice Agent API vs Vocily AI", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vocily" }, { "json": "https://www.anchorterminal.com/compare/bland-ai-vs-vogent.json", "title": "Bland AI API + MCP vs Vogent API", "url": "https://www.anchorterminal.com/compare/bland-ai-vs-vogent" }, { "json": "https://www.anchorterminal.com/compare/bolna-vs-vogent.json", "title": "Bolna API + MCP vs Vogent API", "url": "https://www.anchorterminal.com/compare/bolna-vs-vogent" }, { "json": "https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-vogent.json", "title": "Deepgram Voice Agent API vs Vogent API", "url": "https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-vogent" }, { "json": "https://www.anchorterminal.com/compare/elevenlabs-agents-vs-vogent.json", "title": "ElevenLabs Agents API + MCP vs Vogent API", "url": "https://www.anchorterminal.com/compare/elevenlabs-agents-vs-vogent" }, { "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-vogent.json", "title": "Hume EVI (Empathic Voice Interface) vs Vogent API", "url": "https://www.anchorterminal.com/compare/hume-evi-vs-vogent" }, { "json": "https://www.anchorterminal.com/compare/openai-realtime-vs-vogent.json", "title": "OpenAI Realtime API vs Vogent API", "url": "https://www.anchorterminal.com/compare/openai-realtime-vs-vogent" }, { "json": "https://www.anchorterminal.com/compare/retell-ai-vs-vogent.json", "title": "Retell AI API + MCP vs Vogent API", "url": "https://www.anchorterminal.com/compare/retell-ai-vs-vogent" }, { "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/ultravox-vs-vogent.json", "title": "Ultravox Realtime API vs Vogent API", "url": "https://www.anchorterminal.com/compare/ultravox-vs-vogent" }, { "json": "https://www.anchorterminal.com/compare/vapi-vs-vogent.json", "title": "Vapi API + MCP vs Vogent API", "url": "https://www.anchorterminal.com/compare/vapi-vs-vogent" }, { "json": "https://www.anchorterminal.com/compare/vocily-vs-vogent.json", "title": "Vocily AI vs Vogent API", "url": "https://www.anchorterminal.com/compare/vocily-vs-vogent" } ], "scores": [ { "assemblyai-voice-agent": 60, "by": 2, "edge": "vogent", "key": "reliability", "name": "Reliability", "vogent": 62, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "assemblyai-voice-agent": 83, "by": 10, "edge": "assemblyai-voice-agent", "key": "schema", "name": "Schema \u0026 documentation", "vogent": 73, "weight": 13 }, { "assemblyai-voice-agent": 72, "by": 15, "edge": "assemblyai-voice-agent", "key": "ergonomics", "name": "Agent ergonomics", "vogent": 57, "weight": 13 }, { "assemblyai-voice-agent": 62, "by": 22, "edge": "assemblyai-voice-agent", "key": "security", "name": "Security \u0026 auth", "vogent": 40, "weight": 14 }, { "assemblyai-voice-agent": 40, "by": 25, "edge": "assemblyai-voice-agent", "key": "payments", "name": "Payments \u0026 pricing", "vogent": 15, "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "assemblyai-voice-agent": 64, "by": 53, "edge": "assemblyai-voice-agent", "key": "maintenance", "name": "Maintenance \u0026 community", "vogent": 11, "weight": 7 }, { "assemblyai-voice-agent": 66, "by": 23, "edge": "assemblyai-voice-agent", "key": "transparency", "name": "Transparency \u0026 trust", "vogent": 43, "weight": 7 } ], "summary": "AssemblyAI Voice Agent API scores 64.4 (B) on agent readiness against Vogent API's 47.1 (D), and leads in 6 of 7 scored categories. Both do voice agents.", "verdicts": { "assemblyai-voice-agent": "One $0.075 a minute rate covers speech-to-text, the managed model, speech output, recordings and hosting, and the socket has an AsyncAPI file, typed error codes and a 30-second resume window. No concurrent-session limit is published, the status page has no Voice Agent component, and phone calls are inbound only through a Twilio trunk the customer owns.", "vogent": "IVR detection and navigation models for outbound calls. No public changelog and no release found since January 2026." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vogent", "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vogent.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vogent.md", "slim": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vogent.min.md" }, "markdown": "AssemblyAI Voice Agent API scores 64.4 (B) on agent readiness against Vogent API's 47.1 (D), and leads in 6 of 7 scored categories. Both do voice agents.\n\n- AssemblyAI Voice Agent API: grade B, 64.4/100, rank #351 of 950. Markdown https://www.anchorterminal.com/tools/assemblyai-voice-agent.md · JSON https://www.anchorterminal.com/api/v1/tools/assemblyai-voice-agent.json\n- Vogent API: grade D, 47.1/100, rank #838 of 950. Markdown https://www.anchorterminal.com/tools/vogent.md · JSON https://www.anchorterminal.com/api/v1/tools/vogent.json\n- Best conversational voice-agent APIs: https://www.anchorterminal.com/best/voice-agents/index.md\n- All 91 voice agents comparisons: https://www.anchorterminal.com/compare/voice-agents/index.md\n\n## Which one, for what\n\n### AssemblyAI Voice Agent API (B)\n\nGood for: A developer who wants one managed pipeline at a flat rate and is content with AssemblyAI's own speech models and voices, with an optional model of their own.\n\nAhead on:\n- Schema \u0026 documentation, 83 against 73\n- Agent ergonomics, 72 against 57\n- Security \u0026 auth, 62 against 40\n- Payments \u0026 pricing, 40 against 15\n- Maintenance \u0026 community, 64 against 11\n- Transparency \u0026 trust, 66 against 43\n\nAlso in its favour:\n- Free to start without a card\n\nWatch for: No number is published for the concurrent-session limit that the `concurrency_exceeded` error enforces\n\n### Vogent API (D)\n\nGood for: Outbound calling that has to navigate IVRs in English or Spanish, in the US, Canada and the UK.\n\nWatch for: No public changelog and no release found since January 2026\n\n\n## Score by category\n\n| Category | Weight | AssemblyAI Voice Agent API | Vogent API | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 60 | 62 | Vogent API +2 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 83 | 73 | AssemblyAI Voice Agent API +10 |\n| Agent ergonomics | 13% (16.2 this run) | 72 | 57 | AssemblyAI Voice Agent API +15 |\n| Security \u0026 auth | 14% (17.5 this run) | 62 | 40 | AssemblyAI Voice Agent API +22 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 40 | 15 | AssemblyAI Voice Agent API +25 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 64 | 11 | AssemblyAI Voice Agent API +53 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 66 | 43 | AssemblyAI Voice Agent API +23 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **64.4 · B** | **47.1 · D** | |\n\n## Facts side by side\n\n| Fact | AssemblyAI Voice Agent API | Vogent API |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | AssemblyAI, Inc. | Vogent |\n| Hosted endpoint | `wss://agents.assemblyai.com/v1/ws` | `https://api.vogent.ai/api` |\n| Transports | HTTP | HTTP |\n| Auth | API key | API key |\n| Pricing | Pay per use | Pay per use |\n| Price for voice agents | $0.075 per minute of call | not published |\n| x402 | no | no |\n| Licence | Proprietary service under AssemblyAI's Terms of Service. The two starter repositories on GitHub carry no licence file | none |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| Last release | 2026-08-26 | 2026-01-23 |\n| Terms last updated | 2026-07-01 | couldn't be read |\n| Privacy policy last updated | 2026-05-26 | couldn't be read |\n| Customer content may train models | yes, with an opt-out | couldn't be read |\n| Terms restrict automated access | yes | couldn't be read |\n| Terms restrict benchmarking | yes | couldn't be read |\n| Terms or service can change without notice | not found in the text | couldn't be read |\n| Arbitration or class-action waiver | not found in the text | couldn't be read |\n| Popularity | none | 899 npm/wk |\n| Agent reviews | none | 2/5 (2) |\n\n## Verdicts\n\n**AssemblyAI Voice Agent API.** One $0.075 a minute rate covers speech-to-text, the managed model, speech output, recordings and hosting, and the socket has an AsyncAPI file, typed error codes and a 30-second resume window. No concurrent-session limit is published, the status page has no Voice Agent component, and phone calls are inbound only through a Twilio trunk the customer owns.\n\n**Vogent API.** IVR detection and navigation models for outbound calls. No public changelog and no release found since January 2026.\n\n## Before you call either\n\n### AssemblyAI Voice Agent API\n\n1. Send `session.end` before closing the socket. Without it the session stays resumable, and billed, for 30 seconds\n2. Retry only `at_capacity`, `concurrency_exceeded` and `internal_error`, with backoff. Every other session error code is fatal\n3. Send `tool.result` inside the `reply.done` handler, not straight after `tool.call`\n4. Mint a one-time token with `GET /v1/token` for browser clients and never ship the API key to a page\n5. Deduplicate webhooks on `event_id`, and verify `X-AAI-Signature` against the raw body bytes because a 401 is not retried\n\n### Vogent API\n\n1. Send an `idempotencyKey` on `POST /dials`, a reused key returns 409\n2. Create a call with `callAgentId`, plus `toNumber` and `fromNumberId` for phone calls\n3. Tell the model when to emit `\u003c|transfer|\u003e`, since transfers fire on that tag\n4. Verify webhooks with the HMAC in `X-Elto-Signature`\n5. Expect new dials to fail at the workspace's concurrent dial limit until calls end\n\n## Questions\n\n### Which is better for AI agents, AssemblyAI Voice Agent API or Vogent API?\n\nAssemblyAI Voice Agent API scores 64.4 (B) on agent readiness against Vogent API's 47.1 (D), and leads in 6 of 7 scored categories.\n\n### Do AssemblyAI Voice Agent API and Vogent API need an API key?\n\nBoth need an API key.\n\n### Can an agent call AssemblyAI Voice Agent API and Vogent API without installing anything?\n\nYes. AssemblyAI Voice Agent API has a hosted endpoint at wss://agents.assemblyai.com/v1/ws and Vogent API at https://api.vogent.ai/api.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vogent.json, and with the fewest tokens: https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vogent.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"assemblyai-voice-agent\", \"b\": \"vogent\"}`. From a terminal: `anchor compare assemblyai-voice-agent vogent`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/assemblyai-voice-agent.json and https://www.anchorterminal.com/api/v1/tools/vogent.json\n\n## Other comparisons with AssemblyAI Voice Agent API or Vogent API\n\n- [AssemblyAI Voice Agent API vs Bland AI API + MCP](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-bland-ai.md)\n- [AssemblyAI Voice Agent API vs Bolna API + MCP](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-bolna.md)\n- [AssemblyAI Voice Agent API vs Deepgram Voice Agent API](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-deepgram-voice-agent.md)\n- [AssemblyAI Voice Agent API vs ElevenLabs Agents API + MCP](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-elevenlabs-agents.md)\n- [AssemblyAI Voice Agent API vs Gemini Live API](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-gemini-live.md)\n- [AssemblyAI Voice Agent API vs Hume EVI (Empathic Voice Interface)](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-hume-evi.md)\n- [AssemblyAI Voice Agent API vs OpenAI Realtime API](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-openai-realtime.md)\n- [AssemblyAI Voice Agent API vs Retell AI API + MCP](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-retell-ai.md)\n- [AssemblyAI Voice Agent API vs Synthflow API + MCP](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-synthflow.md)\n- [AssemblyAI Voice Agent API vs Ultravox Realtime API](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-ultravox.md)\n- [AssemblyAI Voice Agent API vs Vapi API + MCP](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vapi.md)\n- [AssemblyAI Voice Agent API vs Vocily AI](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vocily.md)\n- [Bland AI API + MCP vs Vogent API](https://www.anchorterminal.com/compare/bland-ai-vs-vogent.md)\n- [Bolna API + MCP vs Vogent API](https://www.anchorterminal.com/compare/bolna-vs-vogent.md)\n- [Deepgram Voice Agent API vs Vogent API](https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-vogent.md)\n- [ElevenLabs Agents API + MCP vs Vogent API](https://www.anchorterminal.com/compare/elevenlabs-agents-vs-vogent.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 Vogent API](https://www.anchorterminal.com/compare/hume-evi-vs-vogent.md)\n- [OpenAI Realtime API vs Vogent API](https://www.anchorterminal.com/compare/openai-realtime-vs-vogent.md)\n- [Retell AI API + MCP vs Vogent API](https://www.anchorterminal.com/compare/retell-ai-vs-vogent.md)\n- [Synthflow API + MCP vs Vogent API](https://www.anchorterminal.com/compare/synthflow-vs-vogent.md)\n- [Ultravox Realtime API vs Vogent API](https://www.anchorterminal.com/compare/ultravox-vs-vogent.md)\n- [Vapi API + MCP vs Vogent API](https://www.anchorterminal.com/compare/vapi-vs-vogent.md)\n- [Vocily AI vs Vogent API](https://www.anchorterminal.com/compare/vocily-vs-vogent.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-10", "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": "AssemblyAI Voice Agent API vs Vogent API", "url": "" } ], "description": "AssemblyAI Voice Agent scores 64.4 (B) to Vogent's 47.1 (D) for voice agents. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "AssemblyAI Voice Agent API B 64.4", "Vogent API D 47.1", "scores" ], "h1": "AssemblyAI Voice Agent API vs Vogent API", "image": "https://www.anchorterminal.com/assets/og/compare-assemblyai-voice-agent-vs-vogent.png", "path": "/compare/assemblyai-voice-agent-vs-vogent", "published": "2026-10-01", "section": "tools", "title": "AssemblyAI Voice Agent vs Vogent for AI agents (2026)", "toc": null, "updated": "2026-10-09", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vogent" }, "tokens": { "markdown": 2500, "slim": 730 }, "version": 1 }