{ "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": 378, "ranked": true, "rankOf": 1094, "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": "2026-10-15T11:29:45.449537906Z", "lastOk": false, "lastStatus": 0, "lastMs": 0, "lastNote": "unsupported protocol scheme \"wss\"", "authRequired": false, "uptime24h": 0, "uptime30d": 0, "p50ms24h": 0, "p95ms24h": 0, "samples24h": 254, "samples30d": 1446, "days": [ { "date": "2026-10-09", "probes": 85, "ok": 0 }, { "date": "2026-10-10", "probes": 247, "ok": 0 }, { "date": "2026-10-11", "probes": 247, "ok": 0 }, { "date": "2026-10-12", "probes": 247, "ok": 0 }, { "date": "2026-10-13", "probes": 248, "ok": 0 }, { "date": "2026-10-14", "probes": 249, "ok": 0 }, { "date": "2026-10-15", "probes": 123, "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": "2026-10-15T11:31:42.213971018Z" }, "githubStars": 3, "securityTxt": { "url": "https://assemblyai.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-14T15:46:43.866591556Z" }, "llmsTxt": { "url": "https://www.assemblyai.com/docs/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-14T14:13:27.047796716Z" }, "domain": { "domain": "assemblyai.com", "registered": "2016-12-24", "source": "https://rdap.verisign.com/com/v1/domain/assemblyai.com", "checkedAt": "2026-10-11T13:26:56.130405761Z" }, "pages": [ { "url": "https://www.assemblyai.com/docs/billing-and-pricing", "kind": "pricing", "status": 200, "checkedAt": "2026-10-14T21:10:25.325018782Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "3b80ad9644cf" } ], "updatedAt": "2026-10-15T11:31:42.213971018Z" } }, "answer": "AssemblyAI Voice Agent API scores 64.4 (B) on agent readiness against CueLight's 48.8 (D), and leads in 6 of 7 scored categories. CueLight leads on payments \u0026 pricing.", "b": { "slug": "cuelight", "name": "CueLight", "vendor": "sshah03 (individual developer, name not stated)", "vendorUrl": "https://sshah03.github.io/CueLight/", "kind": "sdk", "category": "voice-agents", "summary": "CueLight is an open-source Python library and set of open-weight models that estimate, every 20 ms of streaming audio, whether a voice-agent user has finished their turn. It runs locally from audio alone, in English.", "url": "https://www.anchorterminal.com/tools/cuelight", "markdownUrl": "https://www.anchorterminal.com/tools/cuelight.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/cuelight.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/cuelight.json", "repo": "https://github.com/sshah03/CueLight", "license": "Apache-2.0", "transports": [], "packages": [], "auth": "none", "authNotes": "None. The library runs in the caller's process and opens no port. Weights download anonymously from Hugging Face (sshah03/cuelight-nano, -nano-ssm, -base) on first use, or load from a local folder.", "pricing": "free", "pricingNotes": "Free under Apache-2.0 for code and weights, with no hosted or paid option. The owner pays only for the CPU it runs on. Conditions carried over from the training data ask that it not be used to identify speakers or clone voices.", "priceSummary": "Free · OSS", "where": "local", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the source, README or demo page (checked 2026-10-15). There is nothing to buy.", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 10, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-10-15" }, "docsUrl": "https://github.com/sshah03/CueLight#quick-start", "capabilities": [ "voice.pipeline", "inference.open-weights" ], "tags": [ "sdk", "open-source", "open-weights", "local", "self-hosted", "python", "free", "no-card", "apache-2.0", "pre-1.0" ], "lastRelease": "2026-10-14", "graded": true, "anchor": { "graded": true, "score": 48.8, "grade": "D", "agentReady": false, "rank": 873, "ranked": true, "rankOf": 1094, "categoryRank": 14, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 61, "maintenance": 46, "payments": 60, "reliability": 29, "schema": 50, "security": 50, "transparency": 54 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-15" }, "negative": 0, "verdict": "CueLight gives a voice pipeline a local end-of-turn probability every 20 ms from audio alone, with a 1.9 MB model and Apache-2.0 weights. It is one day old, English only, installs from Git rather than PyPI, has no CI or changelog, and its accuracy figures are the author's own.", "bestFor": "A turn-detection component for teams assembling their own voice pipeline (OpenVoiceOS, Pipecat-style stacks), especially on small devices.", "strengths": [ "Apache-2.0 code and weights, with every training dataset and teacher model named in NOTICE", "Nano is 0.5M parameters and 1.9 MB, with ONNX step files for non-Python runtimes", "Works from audio alone and updates during speech, not only at pauses", "Two tuned presets and a custom policy, behind a four-name Python interface", "Weights load from safetensors, and no telemetry was found in the source" ], "weaknesses": [ "English only, and the author does not plan other languages soon", "Not on PyPI, no tags, releases, changelog or CI, and one commit at the check", "Benchmarks are self-reported, and the presets were tuned on half of the benchmark they are scored on", "Weights download from Hugging Face main branches with no pinned revision", "An unknown preset name falls back silently to default thresholds" ], "agentNotes": [ "Feed 320 float32 samples at 16 kHz mono per `push`. Resample first, or the call raises an AssertionError", "Spell the preset as `snappy` or `careful`. Any other name silently uses default thresholds", "Call `clear()` before a new call or session. Pass `reset_on_turn_start=False` if your pipeline already resets per turn", "Pin weights by downloading them to a local folder and passing that path to `from_pretrained`", "Don't use it to identify speakers or clone voices. The training data's conditions forbid it" ], "metrics": { "kind": "local", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "D", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 48.8 } ], "editorialScores": { "ergonomics": 61, "maintenance": 46, "payments": 60, "reliability": 29, "schema": 50, "security": 50, "transparency": 67 }, "provenanceScore": 40 }, "connect": { "install": "pip install git+https://github.com/sshah03/CueLight" }, "letme": { "capability": "https://letme.dev/voice.pipeline", "tool": "https://letme.dev/cuelight" }, "area": "voice", "provenance": { "legalEntity": "sshah03 (individual GitHub account, no name or organisation stated)", "domain": "sshah03.github.io", "domainRegistered": "", "domainNote": "A library and model weights, not a service. Code on github.com/sshah03, weights on huggingface.co/sshah03, demo on GitHub Pages. No domain of its own.", "endpointOnVendorDomain": null, "terms": "", "privacy": "", "statusPage": "", "changelog": "", "securityTxt": "none", "checked": "2026-10-15", "notes": [ "The LICENSE is Apache-2.0 and NOTICE reads Copyright 2026 sshah03, with third-party model and dataset licences in NOTICE and LICENSES/.", "The GitHub account sshah03 was created on 10 July 2012 and gives no name, company or website.", "No terms or privacy document governs the library or the demo page. Nothing is hosted beyond static GitHub Pages files, so both fields are left out.", "No changelog, tags or GitHub releases. The repository has no SECURITY.md, and github.io serves no security.txt for the project.", "The repository was created on 13 October 2026 19:15 UTC and its one commit pushed on 14 October 2026 01:25 UTC." ], "score": 40 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/cuelight.json" }, "facts": [ { "a": "HTTP API", "b": "SDK + MCP", "name": "Kind" }, { "a": "AssemblyAI, Inc.", "b": "sshah03 (individual developer, name not stated)", "name": "Vendor" }, { "a": "wss://agents.assemblyai.com/v1/ws", "b": "no (local only)", "name": "Hosted endpoint" }, { "a": "HTTP", "b": "", "name": "Transports" }, { "a": "API key", "b": "None", "name": "Auth" }, { "a": "Pay per use", "b": "Free", "name": "Pricing" }, { "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": "Apache-2.0", "name": "Licence" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "no", "name": "llms.txt" }, { "a": "2026-08-26", "b": "2026-10-14", "name": "Last release" }, { "a": "2026-07-01", "b": "no document linked", "name": "Terms last updated" }, { "a": "2026-05-26", "b": "no document linked", "name": "Privacy policy last updated" }, { "a": "yes, with an opt-out", "b": "", "name": "Customer content may train models" }, { "a": "yes", "b": "", "name": "Terms restrict automated access" }, { "a": "yes", "b": "", "name": "Terms restrict benchmarking" }, { "a": "not found in the text", "b": "", "name": "Terms or service can change without notice" }, { "a": "not found in the text", "b": "", "name": "Arbitration or class-action waiver" }, { "a": "none", "b": "10 stars", "name": "Popularity" } ], "faq": [ { "answer": "AssemblyAI Voice Agent API scores 64.4 (B) on agent readiness against CueLight's 48.8 (D), and leads in 6 of 7 scored categories. CueLight leads on payments \u0026 pricing.", "question": "Which is better for AI agents, AssemblyAI Voice Agent API or CueLight?" }, { "answer": "AssemblyAI Voice Agent API has a hosted endpoint at wss://agents.assemblyai.com/v1/ws. No hosted endpoint is listed for CueLight.", "question": "Can an agent call AssemblyAI Voice Agent API and CueLight without installing anything?" }, { "answer": "No open-source release is listed for AssemblyAI Voice Agent API. CueLight is open source (Apache-2.0).", "question": "Are AssemblyAI Voice Agent API and CueLight open source?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 60 against 29", "Schema \u0026 documentation, 83 against 50", "Agent ergonomics, 72 against 61", "Security \u0026 auth, 62 against 50", "Maintenance \u0026 community, 64 against 46", "Transparency \u0026 trust, 66 against 54" ], "also": [ "A hosted endpoint, with nothing to install" ], "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": [ "Payments \u0026 pricing, 60 against 40" ], "also": [ "No key needed to call it", "Open source" ], "goodFor": "A turn-detection component for teams assembling their own voice pipeline (OpenVoiceOS, Pipecat-style stacks), especially on small devices.", "slug": "cuelight", "watchFor": "English only, and the author does not plan other languages soon" } ], "job": { "capability": "voice.pipeline", "name": "Voice pipeline" }, "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/assemblyai-voice-agent-vs-vogent.json", "title": "AssemblyAI Voice Agent API vs Vogent API", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vogent" }, { "json": "https://www.anchorterminal.com/compare/bland-ai-vs-cuelight.json", "title": "Bland AI API + MCP vs CueLight", "url": "https://www.anchorterminal.com/compare/bland-ai-vs-cuelight" }, { "json": "https://www.anchorterminal.com/compare/bolna-vs-cuelight.json", "title": "Bolna API + MCP vs CueLight", "url": "https://www.anchorterminal.com/compare/bolna-vs-cuelight" }, { "json": "https://www.anchorterminal.com/compare/cuelight-vs-deepgram-voice-agent.json", "title": "CueLight vs Deepgram Voice Agent API", "url": "https://www.anchorterminal.com/compare/cuelight-vs-deepgram-voice-agent" }, { "json": "https://www.anchorterminal.com/compare/cuelight-vs-elevenlabs-agents.json", "title": "CueLight vs ElevenLabs Agents API + MCP", "url": "https://www.anchorterminal.com/compare/cuelight-vs-elevenlabs-agents" }, { "json": "https://www.anchorterminal.com/compare/cuelight-vs-hume-evi.json", "title": "CueLight vs Hume EVI (Empathic Voice Interface)", "url": "https://www.anchorterminal.com/compare/cuelight-vs-hume-evi" }, { "json": "https://www.anchorterminal.com/compare/cuelight-vs-retell-ai.json", "title": "CueLight vs Retell AI API + MCP", "url": "https://www.anchorterminal.com/compare/cuelight-vs-retell-ai" }, { "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/cuelight-vs-vapi.json", "title": "CueLight vs Vapi API + MCP", "url": "https://www.anchorterminal.com/compare/cuelight-vs-vapi" }, { "json": "https://www.anchorterminal.com/compare/cuelight-vs-vocily.json", "title": "CueLight vs Vocily AI", "url": "https://www.anchorterminal.com/compare/cuelight-vs-vocily" }, { "json": "https://www.anchorterminal.com/compare/cuelight-vs-vogent.json", "title": "CueLight vs Vogent API", "url": "https://www.anchorterminal.com/compare/cuelight-vs-vogent" } ], "scores": [ { "assemblyai-voice-agent": 60, "by": 31, "cuelight": 29, "edge": "assemblyai-voice-agent", "key": "reliability", "name": "Reliability", "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "assemblyai-voice-agent": 83, "by": 33, "cuelight": 50, "edge": "assemblyai-voice-agent", "key": "schema", "name": "Schema \u0026 documentation", "weight": 13 }, { "assemblyai-voice-agent": 72, "by": 11, "cuelight": 61, "edge": "assemblyai-voice-agent", "key": "ergonomics", "name": "Agent ergonomics", "weight": 13 }, { "assemblyai-voice-agent": 62, "by": 12, "cuelight": 50, "edge": "assemblyai-voice-agent", "key": "security", "name": "Security \u0026 auth", "weight": 14 }, { "assemblyai-voice-agent": 40, "by": 20, "cuelight": 60, "edge": "cuelight", "key": "payments", "name": "Payments \u0026 pricing", "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "assemblyai-voice-agent": 64, "by": 18, "cuelight": 46, "edge": "assemblyai-voice-agent", "key": "maintenance", "name": "Maintenance \u0026 community", "weight": 7 }, { "assemblyai-voice-agent": 66, "by": 12, "cuelight": 54, "edge": "assemblyai-voice-agent", "key": "transparency", "name": "Transparency \u0026 trust", "weight": 7 } ], "summary": "AssemblyAI Voice Agent API scores 64.4 (B) on agent readiness against CueLight's 48.8 (D), and leads in 6 of 7 scored categories. CueLight leads on payments \u0026 pricing. Both do voice pipeline.", "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.", "cuelight": "CueLight gives a voice pipeline a local end-of-turn probability every 20 ms from audio alone, with a 1.9 MB model and Apache-2.0 weights. It is one day old, English only, installs from Git rather than PyPI, has no CI or changelog, and its accuracy figures are the author's own." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-cuelight", "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-cuelight.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-cuelight.md", "slim": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-cuelight.min.md" }, "markdown": "AssemblyAI Voice Agent API scores 64.4 (B) on agent readiness against CueLight's 48.8 (D), and leads in 6 of 7 scored categories. CueLight leads on payments \u0026 pricing. Both do voice pipeline.\n\n- AssemblyAI Voice Agent API: grade B, 64.4/100, rank #378 of 1094. Markdown https://www.anchorterminal.com/tools/assemblyai-voice-agent.md · JSON https://www.anchorterminal.com/api/v1/tools/assemblyai-voice-agent.json\n- CueLight: grade D, 48.8/100, rank #873 of 1094. Markdown https://www.anchorterminal.com/tools/cuelight.md · JSON https://www.anchorterminal.com/api/v1/tools/cuelight.json\n- Best conversational voice-agent APIs: https://www.anchorterminal.com/best/voice-agents/index.md\n- All 102 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- Reliability, 60 against 29\n- Schema \u0026 documentation, 83 against 50\n- Agent ergonomics, 72 against 61\n- Security \u0026 auth, 62 against 50\n- Maintenance \u0026 community, 64 against 46\n- Transparency \u0026 trust, 66 against 54\n\nAlso in its favour:\n- A hosted endpoint, with nothing to install\n\nWatch for: No number is published for the concurrent-session limit that the `concurrency_exceeded` error enforces\n\n### CueLight (D)\n\nGood for: A turn-detection component for teams assembling their own voice pipeline (OpenVoiceOS, Pipecat-style stacks), especially on small devices.\n\nAhead on:\n- Payments \u0026 pricing, 60 against 40\n\nAlso in its favour:\n- No key needed to call it\n- Open source\n\nWatch for: English only, and the author does not plan other languages soon\n\n\n## Score by category\n\n| Category | Weight | AssemblyAI Voice Agent API | CueLight | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 60 | 29 | AssemblyAI Voice Agent API +31 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 83 | 50 | AssemblyAI Voice Agent API +33 |\n| Agent ergonomics | 13% (16.2 this run) | 72 | 61 | AssemblyAI Voice Agent API +11 |\n| Security \u0026 auth | 14% (17.5 this run) | 62 | 50 | AssemblyAI Voice Agent API +12 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 40 | 60 | CueLight +20 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 64 | 46 | AssemblyAI Voice Agent API +18 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 66 | 54 | AssemblyAI Voice Agent API +12 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **64.4 · B** | **48.8 · D** | |\n\n## Facts side by side\n\n| Fact | AssemblyAI Voice Agent API | CueLight |\n| --- | --- | --- |\n| Kind | HTTP API | SDK + MCP |\n| Vendor | AssemblyAI, Inc. | sshah03 (individual developer, name not stated) |\n| Hosted endpoint | `wss://agents.assemblyai.com/v1/ws` | no (local only) |\n| Transports | HTTP | |\n| Auth | API key | None |\n| Pricing | Pay per use | Free |\n| x402 | no | no |\n| Licence | Proprietary service under AssemblyAI's Terms of Service. The two starter repositories on GitHub carry no licence file | Apache-2.0 |\n| Read-only variant documented | no | no |\n| llms.txt | yes | no |\n| Last release | 2026-08-26 | 2026-10-14 |\n| Terms last updated | 2026-07-01 | no document linked |\n| Privacy policy last updated | 2026-05-26 | no document linked |\n| Customer content may train models | yes, with an opt-out | |\n| Terms restrict automated access | yes | |\n| Terms restrict benchmarking | yes | |\n| Terms or service can change without notice | not found in the text | |\n| Arbitration or class-action waiver | not found in the text | |\n| Popularity | none | 10 stars |\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**CueLight.** CueLight gives a voice pipeline a local end-of-turn probability every 20 ms from audio alone, with a 1.9 MB model and Apache-2.0 weights. It is one day old, English only, installs from Git rather than PyPI, has no CI or changelog, and its accuracy figures are the author's own.\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### CueLight\n\n1. Feed 320 float32 samples at 16 kHz mono per `push`. Resample first, or the call raises an AssertionError\n2. Spell the preset as `snappy` or `careful`. Any other name silently uses default thresholds\n3. Call `clear()` before a new call or session. Pass `reset_on_turn_start=False` if your pipeline already resets per turn\n4. Pin weights by downloading them to a local folder and passing that path to `from_pretrained`\n5. Don't use it to identify speakers or clone voices. The training data's conditions forbid it\n\n## Questions\n\n### Which is better for AI agents, AssemblyAI Voice Agent API or CueLight?\n\nAssemblyAI Voice Agent API scores 64.4 (B) on agent readiness against CueLight's 48.8 (D), and leads in 6 of 7 scored categories. CueLight leads on payments \u0026 pricing.\n\n### Can an agent call AssemblyAI Voice Agent API and CueLight without installing anything?\n\nAssemblyAI Voice Agent API has a hosted endpoint at wss://agents.assemblyai.com/v1/ws. No hosted endpoint is listed for CueLight.\n\n### Are AssemblyAI Voice Agent API and CueLight open source?\n\nNo open-source release is listed for AssemblyAI Voice Agent API. CueLight is open source (Apache-2.0).\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-cuelight.json, and with the fewest tokens: https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-cuelight.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"assemblyai-voice-agent\", \"b\": \"cuelight\"}`. From a terminal: `anchor compare assemblyai-voice-agent cuelight`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/assemblyai-voice-agent.json and https://www.anchorterminal.com/api/v1/tools/cuelight.json\n\n## Other comparisons with AssemblyAI Voice Agent API or CueLight\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- [AssemblyAI Voice Agent API vs Vogent API](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vogent.md)\n- [Bland AI API + MCP vs CueLight](https://www.anchorterminal.com/compare/bland-ai-vs-cuelight.md)\n- [Bolna API + MCP vs CueLight](https://www.anchorterminal.com/compare/bolna-vs-cuelight.md)\n- [CueLight vs Deepgram Voice Agent API](https://www.anchorterminal.com/compare/cuelight-vs-deepgram-voice-agent.md)\n- [CueLight vs ElevenLabs Agents API + MCP](https://www.anchorterminal.com/compare/cuelight-vs-elevenlabs-agents.md)\n- [CueLight vs Hume EVI (Empathic Voice Interface)](https://www.anchorterminal.com/compare/cuelight-vs-hume-evi.md)\n- [CueLight vs Retell AI API + MCP](https://www.anchorterminal.com/compare/cuelight-vs-retell-ai.md)\n- [CueLight vs Synthflow API + MCP](https://www.anchorterminal.com/compare/cuelight-vs-synthflow.md)\n- [CueLight vs Vapi API + MCP](https://www.anchorterminal.com/compare/cuelight-vs-vapi.md)\n- [CueLight vs Vocily AI](https://www.anchorterminal.com/compare/cuelight-vs-vocily.md)\n- [CueLight vs Vogent API](https://www.anchorterminal.com/compare/cuelight-vs-vogent.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": "2026-10-15", "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": "AssemblyAI Voice Agent API vs CueLight", "url": "" } ], "description": "AssemblyAI Voice Agent scores 64.4 (B) to CueLight's 48.8 (D) for voice pipeline. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "AssemblyAI Voice Agent API B 64.4", "CueLight D 48.8", "scores" ], "h1": "AssemblyAI Voice Agent API vs CueLight", "image": "https://www.anchorterminal.com/assets/og/compare-assemblyai-voice-agent-vs-cuelight.png", "path": "/compare/assemblyai-voice-agent-vs-cuelight", "published": "2026-10-01", "section": "tools", "title": "AssemblyAI Voice Agent vs CueLight for AI agents (2026)", "toc": null, "updated": "2026-10-15", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-cuelight" }, "tokens": { "markdown": 2600, "slim": 730 }, "version": 1 }