{ "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", "dns": "assemblyai-voice-agent.grade.anchorterminal.com", "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": "No Voice Agent API price was found on AssemblyAI's pricing page or in its billing docs on 2 November 2026. On 9 October both gave $4.50 an hour ($0.075 a minute), billed per second from socket open to session end, covering speech-to-text, the managed model, speech output and recordings. The $50 new-account credit is now listed for speech-to-text, Speech Understanding and Guardrails only. LLM Gateway tokens and Twilio carrier minutes are billed separately (https://www.assemblyai.com/pricing, https://www.assemblyai.com/docs/billing-and-pricing, checked 2026-11-02).", "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", "closed-source", "llms-txt", "webhooks", "streaming", "pipeline", "python", "javascript", "status-page", "soc2" ], "lastRelease": "2026-09-16", "graded": true, "anchor": { "graded": true, "score": 56.4, "grade": "C", "agentReady": false, "rank": 822, "ranked": true, "rankOf": 1486, "categoryRank": 15, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 72, "maintenance": 64, "payments": 0, "reliability": 65, "schema": 83, "security": 55, "transparency": 68 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "low", "date": "2026-11-02" }, "negative": -3, "negativeNotes": [ "2026-09-01: AssemblyAI's changelog entry \"Fix: Reader Role Permissions Enforced for API Tokens\" says dashboard users with the Reader role could create, edit and delete API tokens, the keys that also open Voice Agent sessions. A released fix of a described flaw with no advisory takes -3, read as assemblyai-stt on the same entry (https://www.assemblyai.com/changelog)" ], "verdict": "The socket has an AsyncAPI file, typed error codes with retry advice and a 30-second resume window, and the status feed shows only partial realtime incidents since August. On 2 November AssemblyAI's pricing page and billing docs no longer listed the API or its rate, no concurrent-session limit is published, and telephony is inbound only.", "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": [ "AsyncAPI 3.0 file for the socket, an OpenAPI file for the token endpoint, and a Markdown copy of every Voice Agent 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", "Pre-connect requests (16 September 2026) can look up an inbound caller before the call is answered" ], "weaknesses": [ "No Voice Agent API price on the pricing page or in the billing docs on 2 November 2026, and the free credit no longer names it", "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" ], "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": 4, "avgRating": 3.5, "history": [ { "basis": "public evidence", "confidence": "low", "grade": "C", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 56.4 } ], "editorialScores": { "ergonomics": 72, "maintenance": 64, "payments": 0, "reliability": 65, "schema": 83, "security": 55, "transparency": 51 }, "provenanceScore": 84, "checked": { "categories": { "ergonomics": "2026-11-02", "maintenance": "2026-11-02", "payments": "2026-11-02", "reliability": "2026-11-02", "schema": "2026-11-02", "security": "2026-11-02", "transparency": "2026-11-02" }, "last": "2026-11-02", "lastMoved": "2026-11-02", "oldest": "2026-11-02", "stale": false, "staleAfterDays": 90 } }, "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", "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": "2026-11-02", "notes": [ "www.assemblyai.com's robots.txt disallows /.well-known, so security.txt wasn't read and securityTxt stays unknown.", "The subprocessor list at /legal/subprocessors redirects to app.vanta.com, whose robots.txt disallows every path.", "status.assemblyai.com disallows /api/ and /embed/; history.atom was read." ], "score": 84 }, "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": "2026-11-07T18:20:11.287781618Z", "lastOk": false, "lastStatus": 0, "lastMs": 0, "lastNote": "unsupported protocol scheme \"wss\"", "authRequired": false, "uptime24h": 0, "uptime30d": 0, "p50ms24h": 0, "p95ms24h": 0, "samples24h": 239, "samples30d": 7205, "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": 253, "ok": 0 }, { "date": "2026-10-16", "probes": 252, "ok": 0 }, { "date": "2026-10-17", "probes": 253, "ok": 0 }, { "date": "2026-10-18", "probes": 256, "ok": 0 }, { "date": "2026-10-19", "probes": 255, "ok": 0 }, { "date": "2026-10-20", "probes": 252, "ok": 0 }, { "date": "2026-10-21", "probes": 253, "ok": 0 }, { "date": "2026-10-22", "probes": 253, "ok": 0 }, { "date": "2026-10-23", "probes": 248, "ok": 0 }, { "date": "2026-10-24", "probes": 251, "ok": 0 }, { "date": "2026-10-25", "probes": 250, "ok": 0 }, { "date": "2026-10-26", "probes": 252, "ok": 0 }, { "date": "2026-10-27", "probes": 249, "ok": 0 }, { "date": "2026-10-28", "probes": 251, "ok": 0 }, { "date": "2026-10-29", "probes": 249, "ok": 0 }, { "date": "2026-10-30", "probes": 248, "ok": 0 }, { "date": "2026-10-31", "probes": 251, "ok": 0 }, { "date": "2026-11-01", "probes": 249, "ok": 0 }, { "date": "2026-11-02", "probes": 250, "ok": 0 }, { "date": "2026-11-03", "probes": 248, "ok": 0 }, { "date": "2026-11-04", "probes": 246, "ok": 0 }, { "date": "2026-11-05", "probes": 185, "ok": 0 }, { "date": "2026-11-06", "probes": 241, "ok": 0 }, { "date": "2026-11-07", "probes": 187, "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": "2026-11-07T18:20:33.101817943Z" }, "githubStars": 3, "securityTxt": { "url": "https://assemblyai.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-11-07T16:01:59.173300071Z" }, "llmsTxt": { "url": "https://www.assemblyai.com/docs/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:31:38.515960891Z" }, "domain": { "domain": "assemblyai.com", "registered": "2016-12-24", "source": "https://rdap.verisign.com/com/v1/domain/assemblyai.com", "checkedAt": "2026-11-01T14:13:09.893972788Z" }, "pages": [ { "url": "https://www.assemblyai.com/docs/billing-and-pricing", "kind": "pricing", "status": 200, "checkedAt": "2026-11-07T14:25:01.876438774Z", "changedAt": "2026-11-06T13:46:09.365947359Z", "fingerprint": "ec67f4032d24" } ], "github": { "repo": "assemblyai/voice-agent-starter-python", "checkedAt": "2026-11-02T08:31:58.26657978Z", "stars": 3, "archived": false, "issuesEnabled": true, "pushedAt": "2026-08-16T07:35:00Z", "openIssues": 0, "openPRs": 0, "issuesOpened90d": 0, "issuesClosed90d": 0, "prsMerged90d": 0 }, "updatedAt": "2026-11-07T18:20:11.287781618Z" } }, "answer": "Inworld Realtime API scores 60.1 (C) on agent readiness against AssemblyAI Voice Agent API's 56.4 (C), and leads in 3 of 7 scored categories. AssemblyAI Voice Agent API leads on schema \u0026 documentation and transparency \u0026 trust.", "b": { "slug": "inworld-realtime", "name": "Inworld Realtime API", "vendor": "Inworld AI", "vendorUrl": "https://inworld.ai", "kind": "http-api", "category": "voice-agents", "summary": "Inworld's Realtime API runs spoken conversations over WebSocket or WebRTC, chaining Inworld STT, an LLM chosen by the developer and Inworld TTS, with turn detection, interruptions and tool calling. It follows OpenAI's Realtime protocol.", "url": "https://www.anchorterminal.com/tools/inworld-realtime", "markdownUrl": "https://www.anchorterminal.com/tools/inworld-realtime.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/inworld-realtime.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/inworld-realtime.json", "dns": "inworld-realtime.grade.anchorterminal.com", "transports": [ "websocket", "http" ], "packages": [ { "registry": "npm", "name": "@inworld/cli" } ], "auth": "api-key", "authNotes": "Servers send `Authorization: Basic` with the Base64 `key_id:secret` credential. Browsers send `Authorization: Bearer` with a session token minted server side. The `key` query parameter in the WebSocket URL is a session ID, not a secret.", "pricing": "usage", "pricingNotes": "No per-minute or per-session price. A session is billed as its STT ($0.10 to $0.15 an hour), its LLM tokens at the model's rate and its TTS characters (TTS-2 from $25 per million on the free plan). Segments already sent to TTS are billed after an interruption.", "priceSummary": "Pay per use", "where": "local", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the docs, llms.txt or pricing page (checked 2026-11-06). Plans and credits are bought in the Portal.", "endpoints": [] }, "toolCount": 0, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-11-06" }, "docsUrl": "https://docs.inworld.ai/realtime/overview", "llmsTxt": "https://docs.inworld.ai/llms.txt", "capabilities": [ "voice.agent", "voice.pipeline", "voice.tools", "voice.telephony" ], "tags": [ "hosted", "usage", "free-tier", "closed-source", "llms-txt", "streaming", "websocket", "webrtc", "openai-compatible", "enterprise" ], "lastRelease": "2026-10-16", "graded": true, "anchor": { "graded": true, "score": 60.1, "grade": "C", "agentReady": false, "rank": 668, "ranked": true, "rankOf": 1486, "categoryRank": 12, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 68, "maintenance": 71, "payments": 40, "reliability": 62, "schema": 60, "security": 58, "transparency": 63 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-06" }, "negative": 0, "verdict": "Inworld's Realtime API speaks OpenAI's Realtime protocol over WebSocket or WebRTC, with a choice of LLM, client-side tools and dated release notes. Cost is the sum of STT, LLM and TTS usage with no per-minute price, there is no machine-readable event schema, and status history couldn't be read.", "bestFor": "Teams moving off OpenAI's Realtime API who want a choice of LLM and Inworld voices.", "strengths": [ "Follows OpenAI's Realtime events, with a migration guide that changes only the URL, key and a few defaults", "Dated release notes name affected clients and required actions for each compatibility change", "A choice of LLM through Inworld's router, with prompt caching on Anthropic models", "Concurrent sessions from 10 on the free plan to 1,000 on Growth", "Zero data retention covers session content from the Developer plan up" ], "weaknesses": [ "No per-minute price. A session's cost depends on STT, LLM tokens and TTS characters, and interrupted segments are still billed", "No AsyncAPI or other machine-readable schema for the socket events", "Status history couldn't be read, and an SLA exists only for Enterprise", "The 21 July 2026 release changed response and item shapes for existing clients", "Zero data retention doesn't cover requests routed to third-party LLM providers" ], "agentNotes": [ "Set the auto follow-up off if your client sends its own `response.create` after a tool result, or replies double", "Read `response.done` usage as an estimate and mute input audio when nobody speaks, since STT bills every second sent", "Use `response.speak` for fixed greetings, which skips the LLM", "Treat `unsupported_field` errors as warnings and keep the session open", "Mint browser session tokens on your server and never ship the Basic credential to a client" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 60.1 } ], "editorialScores": { "ergonomics": 68, "maintenance": 71, "payments": 40, "reliability": 62, "schema": 60, "security": 58, "transparency": 51 }, "provenanceScore": 75, "checked": { "categories": { "ergonomics": "2026-11-06", "maintenance": "2026-11-06", "payments": "2026-11-06", "reliability": "2026-11-06", "schema": "2026-11-06", "security": "2026-11-06", "transparency": "2026-11-06" }, "last": "2026-11-06", "oldest": "2026-11-06", "stale": false, "staleAfterDays": 90 } }, "connect": { "install": "npm install -g @inworld/cli" }, "letme": { "capability": "https://letme.dev/voice.agent", "tool": "https://letme.dev/inworld-realtime" }, "sameCompany": [ "inworld-stt", "inworld-tts", "inworld-voice-cloning" ], "area": "voice", "unitPrices": [ { "item": "Speech recognition in a session", "unit": "audio-minute", "usd": 0.0025, "note": "STT-1 at $0.15 an hour On-Demand, $0.10 on paid plans" }, { "item": "Agent speech, TTS-2", "unit": "1m-chars", "usd": 25, "note": "free On-Demand plan; lower on paid plans" } ], "provenance": { "legalEntity": "Theai, Inc. dba Inworld AI", "domain": "inworld.ai", "domainRegistered": "", "endpointOnVendorDomain": true, "terms": "https://inworld.ai/terms", "privacy": "https://inworld.ai/privacy", "statusPage": "https://status.inworld.ai", "changelog": "https://docs.inworld.ai/release-notes/realtime", "securityTxt": "none", "checked": "2026-11-06", "notes": [ "The Terms of Service (effective 11 June 2025) are an agreement with Theai, Inc. dba Inworld AI under California law, with courts in Santa Clara. The Privacy Notice (last updated 18 January 2026) names Theai, Inc.", "inworld.ai/.well-known/security.txt returns 404. The security page links a vulnerability report form.", "status.inworld.ai runs the open-source issue-status app, which draws incidents from GitHub issues in inworld-ai/inworld-issue-status. Its history wasn't read, because GitHub's robots.txt couldn't be read from our environment.", "inworld.ai's robots.txt allows Claude agents on the paths read and sets `Content-Signal: ai-train=no, search=yes, ai-input=no`. docs.inworld.ai has no such signal.", "The domain's registration date wasn't established, because the RDAP lookup failed.", "firstReleased is left empty. The public Realtime release notes start on 21 July 2026 and no launch date was found." ], "score": 75 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/inworld-realtime.json", "live": { "slug": "inworld-realtime", "vendorStatus": { "page": "https://status.inworld.ai", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-11-07T04:47:57.03709454Z" }, "versions": [ { "registry": "npm", "name": "@inworld/cli", "version": "1.5.0", "seenAt": "2026-11-06T23:35:04.551623033Z" } ], "npmWeekly": 290, "securityTxt": { "url": "https://inworld.ai/.well-known/security.txt", "state": "none", "checkedAt": "2026-11-07T16:01:11.794771951Z" }, "llmsTxt": { "url": "https://docs.inworld.ai/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:32:46.028273902Z" }, "pages": [ { "url": "https://docs.inworld.ai/release-notes/realtime", "kind": "changelog", "status": 200, "checkedAt": "2026-11-07T14:06:42.218731652Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "9ae0f1f05b69" }, { "url": "https://inworld.ai/privacy", "kind": "privacy", "status": 304, "checkedAt": "2026-11-07T14:11:39.031139211Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "99dc39a9de92" }, { "url": "https://inworld.ai/terms", "kind": "terms", "status": 304, "checkedAt": "2026-11-07T14:11:41.181276356Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "777d881cbf9b" } ], "updatedAt": "2026-11-07T16:01:11.794771951Z" } }, "edges": [ { "by": 40, "category": "payments", "leads": "inworld-realtime", "name": "Payments \u0026 pricing", "reasons": { "a": "No x402, MPP or L402 (0 of 40). On 2 November the pricing page lists speech-to-text, dictation, text-to-speech and LLM Gateway prices but no Voice Agent API price, and the billing docs have no Voice Agent section. The $4.50 an hour rate the 9 October check read on both is no longer published, and no other price page was found (0, was 20). The billing docs now say new accounts' $50 of credit applies to pre-recorded and real-time speech-to-text, Speech Understanding and Guardrails, without naming the Voice Agent API, where on 9 October they said it was covered (0, was 20). A person has to sign up in a browser to get the first key, and no key-creation API was found (0). 0+0+0+0 = 0.", "b": "No x402, MPP or L402 (0). No per-session price, but each billed part (STT per hour, TTS per character, LLM per token) is priced publicly (20). On-Demand includes free STT and TTS allowances and lists no payment method, though some premium LLMs need a card on file (20). A person signs up in a browser before a key exists (0). Total 40." }, "scores": { "a": 0, "b": 40 } }, { "by": 23, "category": "schema", "leads": "assemblyai-voice-agent", "name": "Schema \u0026 documentation", "reasons": { "a": "An AsyncAPI 3.0 file describes the socket and an OpenAPI 3.0.3 file the token endpoint. No description file was found for the agents, sessions and webhook REST endpoints, and the AsyncAPI file lacks `language_codes`, `voice_focus`, `transcript.agent.delta` and `is_error`, which the docs added on 23 July 2026 (19 of 25). llms.txt, a Markdown copy of each page and a docs MCP server (10). Operations and fields say what they are for and when to use them, such as when to choose `hold` over `interactive` execution (17 of 20). Enums, ranges and defaults on audio encoding, turn detection and timeouts. Tool `parameters` are a JSON Schema the server does not validate at `session.update` (12 of 15). Examples in cURL, Python and JavaScript, and tables of session error codes with close codes (13 of 15). A dated public changelog tagged by product and a `/v1` path, with no written versioning policy found (12 of 15).", "b": "No AsyncAPI or other machine-readable file for the socket, and the spec paths redirect (0). llms.txt, Markdown twins and a docs MCP server (10). The overview, OpenAI migration guide, `providerData` reference and the billing page's account of how a session is counted say what to use when (16 of 20). The reference lists every client and server event with field types and required marks, as text rather than a schema (12 of 15). JavaScript and Python example projects and an error event with `type`, `code` and `param`, without a list of codes (9 of 15). Dated release notes with affected clients and required actions, but no API version beyond `/v1` (13 of 15). Total 60." }, "scores": { "a": 83, "b": 60 } }, { "by": 7, "category": "maintenance", "leads": "inworld-realtime", "name": "Maintenance \u0026 community", "reasons": { "a": "The last changelog entry tagged Voice Agent API is Pre-Connect Requests on 16 September 2026 (47 days before 2 November), which the 9 October check didn't count (20). Five tagged entries since 4 August (18 August, three on 26 August, 16 September) (20). A public changelog that records fixes, a support address and a Discord link we did not test (11 of 15 for a closed service). The Python and Node SDKs still have no Voice Agent client (Node 4.42.0 of 26 October added text-to-speech clients), and the two starter repositories were last changed on 16 August 2026 (8 of 15). The starters need no dependencies and have no licence file, tests or CI (5 of 10). 20+20+11+8+5 = 64.", "b": "Release note of 16 October 2026 (`cache_transcript`), 21 days ago (30). Three dated Realtime entries in the 90 days from 8 August, on 14 September, 23 September and 16 October (20). Discord and support@inworld.ai, with no evidence of answers read (8 of 15). Works with OpenAI's Realtime clients and the CLI is current at 1.5.0, but there is no Inworld Realtime SDK (8 of 15). CLI on npm under MIT, CI not read (5 of 10). Total 71." }, "scores": { "a": 64, "b": 71 } }, { "by": 5, "category": "transparency", "leads": "assemblyai-voice-agent", "name": "Transparency \u0026 trust", "reasons": { "a": "A closed service with a clear service agreement. The starter repositories have no licence file (15 of 30). The Terms of Service grant a licence to train on Customer Data by default, the opt-out needs a paid plan, and the retention page gives periods for streaming, sync, dictation, asynchronous and LLM Gateway data but none for Voice Agent sessions, which are recorded and stored. A DPA is published and the privacy policy states Data Privacy Framework certification (14 of 30). The changelog dates deprecations ahead of time, such as the 11 July 2026 notice of a change on 7 August, and the terms promise reasonable prior notice of major changes. No written deprecation policy was found (12 of 20). The subprocessor list at /legal/subprocessors redirects to a Vanta trust centre whose robots.txt disallows every path, so it is unread. US and EU endpoints are mentioned, with no EU host named for the Voice Agent API in the pages read (10 of 20). 15+14+12+10 = 51.", "b": "Closed service with clear terms naming Theai, Inc. dba Inworld AI (15). The ZDR page says what a session keeps and that third-party LLM requests aren't covered, but the terms and privacy notice disagree on training (12 of 30). Release notes flag potentially breaking changes with the clients affected and what to do, without stating a notice period (14 of 20). US headquarters with EU and India residency on Enterprise, and no sub-processor list in the docs, while sessions may route to third-party LLM providers (10 of 20). Total 51." }, "scores": { "a": 68, "b": 63 } } ], "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "AssemblyAI, Inc.", "b": "Inworld AI", "name": "Vendor" }, { "a": "wss://agents.assemblyai.com/v1/ws", "b": "no (local only)", "name": "Hosted endpoint" }, { "a": "HTTP", "b": "websocket, HTTP", "name": "Transports" }, { "a": "API key", "b": "API key", "name": "Auth" }, { "a": "Pay per use", "b": "Pay per use", "name": "Pricing" }, { "a": "not published", "b": "$25 per 1M characters", "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": "none", "b": "0", "name": "Tools exposed" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "2026-09-16", "b": "2026-10-16", "name": "Last release" }, { "a": "2026-07-01", "b": "2025-06-11", "name": "Terms last updated" }, { "a": "2026-05-26", "b": "2026-01-18", "name": "Privacy policy last updated" }, { "a": "yes, with an opt-out", "b": "not found in the text", "name": "Customer content may train models" }, { "a": "yes", "b": "not found in the text", "name": "Terms restrict automated access" }, { "a": "yes", "b": "not found in the text", "name": "Terms restrict benchmarking" }, { "a": "not found in the text", "b": "not found in the text", "name": "Terms or service can change without notice" }, { "a": "not found in the text", "b": "not found in the text", "name": "Arbitration or class-action waiver" }, { "a": "3.5/5 (4)", "b": "none", "name": "Agent reviews" } ], "faq": [ { "answer": "Inworld Realtime API scores 60.1 (C) on agent readiness against AssemblyAI Voice Agent API's 56.4 (C), and leads in 3 of 7 scored categories. AssemblyAI Voice Agent API leads on schema \u0026 documentation and transparency \u0026 trust.", "question": "Which is better for AI agents, AssemblyAI Voice Agent API or Inworld Realtime API?" }, { "answer": "Both need an API key.", "question": "Do AssemblyAI Voice Agent API and Inworld Realtime API need an API key?" }, { "answer": "AssemblyAI Voice Agent API has a hosted endpoint at wss://agents.assemblyai.com/v1/ws. No hosted endpoint is listed for Inworld Realtime API.", "question": "Can an agent call AssemblyAI Voice Agent API and Inworld Realtime API without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Schema \u0026 documentation, 83 against 60", "Transparency \u0026 trust, 68 against 63" ], "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 Voice Agent API price on the pricing page or in the billing docs on 2 November 2026, and the free credit no longer names it" }, { "aheadOn": [ "Payments \u0026 pricing, 40 against 0", "Maintenance \u0026 community, 71 against 64" ], "also": [ "No incidents deducted, where AssemblyAI Voice Agent API loses 3 points for them" ], "goodFor": "Teams moving off OpenAI's Realtime API who want a choice of LLM and Inworld voices.", "slug": "inworld-realtime", "watchFor": "No per-minute price. A session's cost depends on STT, LLM tokens and TTS characters, and interrupted segments are still billed" } ], "history": { "assemblyai-voice-agent": [ { "causes": [ "pricing", "correction" ], "date": "2026-11-02", "delta": -8.2, "from": 64.6, "fromGrade": "B", "to": 56.4, "toGrade": "C" }, { "causes": [ "method" ], "date": "2026-10-27", "delta": 0.2, "from": 64.4, "fromGrade": "B", "to": 64.6, "toGrade": "B" } ], "inworld-realtime": null }, "job": { "capability": "voice.agent", "name": "Voice agents" }, "others": [ { "json": "https://www.anchorterminal.com/compare/amazon-nova-sonic-vs-assemblyai-voice-agent.json", "title": "Amazon Nova 2 Sonic vs AssemblyAI Voice Agent API", "url": "https://www.anchorterminal.com/compare/amazon-nova-sonic-vs-assemblyai-voice-agent" }, { "json": "https://www.anchorterminal.com/compare/amazon-nova-sonic-vs-inworld-realtime.json", "title": "Amazon Nova 2 Sonic vs Inworld Realtime API", "url": 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Realtime API", "url": "https://www.anchorterminal.com/compare/harmony-ai-vs-inworld-realtime" }, { "json": "https://www.anchorterminal.com/compare/hume-evi-vs-inworld-realtime.json", "title": "Hume EVI (Empathic Voice Interface) vs Inworld Realtime API", "url": "https://www.anchorterminal.com/compare/hume-evi-vs-inworld-realtime" }, { "json": "https://www.anchorterminal.com/compare/inworld-realtime-vs-livekit-agents.json", "title": "Inworld Realtime API vs LiveKit Agents", "url": "https://www.anchorterminal.com/compare/inworld-realtime-vs-livekit-agents" }, { "json": "https://www.anchorterminal.com/compare/inworld-realtime-vs-openai-realtime.json", "title": "Inworld Realtime API vs OpenAI Realtime API", "url": "https://www.anchorterminal.com/compare/inworld-realtime-vs-openai-realtime" }, { "json": "https://www.anchorterminal.com/compare/inworld-realtime-vs-pipecat.json", "title": "Inworld Realtime API vs Pipecat", "url": 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"https://www.anchorterminal.com/compare/inworld-realtime-vs-ultravox.json", "title": "Inworld Realtime API vs Ultravox Realtime API", "url": "https://www.anchorterminal.com/compare/inworld-realtime-vs-ultravox" }, { "json": "https://www.anchorterminal.com/compare/inworld-realtime-vs-vaani-voice.json", "title": "Inworld Realtime API vs Vaani Developer Platform", "url": "https://www.anchorterminal.com/compare/inworld-realtime-vs-vaani-voice" }, { "json": "https://www.anchorterminal.com/compare/inworld-realtime-vs-vapi.json", "title": "Inworld Realtime API vs Vapi API + MCP", "url": "https://www.anchorterminal.com/compare/inworld-realtime-vs-vapi" }, { "json": "https://www.anchorterminal.com/compare/inworld-realtime-vs-vocily.json", "title": "Inworld Realtime API vs Vocily AI", "url": "https://www.anchorterminal.com/compare/inworld-realtime-vs-vocily" }, { "json": "https://www.anchorterminal.com/compare/inworld-realtime-vs-vogent.json", "title": "Inworld Realtime API vs Vogent API", "url": "https://www.anchorterminal.com/compare/inworld-realtime-vs-vogent" }, { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-cuelight.json", "title": "AssemblyAI Voice Agent API vs CueLight", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-cuelight" }, { "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-pipecat-phonellm.json", "title": "AssemblyAI Voice Agent API vs Pipecat PhoneLLM", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-pipecat-phonellm" }, { "json": "https://www.anchorterminal.com/compare/cuelight-vs-inworld-realtime.json", "title": "CueLight vs Inworld Realtime API", "url": "https://www.anchorterminal.com/compare/cuelight-vs-inworld-realtime" }, { "json": "https://www.anchorterminal.com/compare/inworld-realtime-vs-pipecat-phonellm.json", "title": "Inworld Realtime API vs Pipecat PhoneLLM", "url": "https://www.anchorterminal.com/compare/inworld-realtime-vs-pipecat-phonellm" } ], "panel": null, "scores": [ { "assemblyai-voice-agent": 65, "by": 3, "edge": "assemblyai-voice-agent", "inworld-realtime": 62, "key": "reliability", "name": "Reliability", "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "assemblyai-voice-agent": 83, "by": 23, "edge": "assemblyai-voice-agent", "inworld-realtime": 60, "key": "schema", "name": "Schema \u0026 documentation", "weight": 13 }, { "assemblyai-voice-agent": 72, "by": 4, "edge": "assemblyai-voice-agent", "inworld-realtime": 68, "key": "ergonomics", "name": "Agent ergonomics", "weight": 13 }, { "assemblyai-voice-agent": 55, "by": 3, "edge": "inworld-realtime", "inworld-realtime": 58, "key": "security", "name": "Security \u0026 auth", "weight": 14 }, { "assemblyai-voice-agent": 0, "by": 40, "edge": "inworld-realtime", "inworld-realtime": 40, "key": "payments", "name": "Payments \u0026 pricing", "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "assemblyai-voice-agent": 64, "by": 7, "edge": "inworld-realtime", "inworld-realtime": 71, "key": "maintenance", "name": "Maintenance \u0026 community", "weight": 7 }, { "assemblyai-voice-agent": 68, "by": 5, "edge": "assemblyai-voice-agent", "inworld-realtime": 63, "key": "transparency", "name": "Transparency \u0026 trust", "weight": 7 } ], "summary": "Inworld Realtime API scores 60.1 (C) on agent readiness against AssemblyAI Voice Agent API's 56.4 (C), and leads in 3 of 7 scored categories. AssemblyAI Voice Agent API leads on schema \u0026 documentation and transparency \u0026 trust. Both do voice agents.", "tasks": null, "tutorials": [], "verdicts": { "assemblyai-voice-agent": "The socket has an AsyncAPI file, typed error codes with retry advice and a 30-second resume window, and the status feed shows only partial realtime incidents since August. On 2 November AssemblyAI's pricing page and billing docs no longer listed the API or its rate, no concurrent-session limit is published, and telephony is inbound only.", "inworld-realtime": "Inworld's Realtime API speaks OpenAI's Realtime protocol over WebSocket or WebRTC, with a choice of LLM, client-side tools and dated release notes. Cost is the sum of STT, LLM and TTS usage with no per-minute price, there is no machine-readable event schema, and status history couldn't be read." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-inworld-realtime", "json": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-inworld-realtime.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-inworld-realtime.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-inworld-realtime.min.md" }, "markdown": "Inworld Realtime API scores 60.1 (C) on agent readiness against AssemblyAI Voice Agent API's 56.4 (C), and leads in 3 of 7 scored categories. AssemblyAI Voice Agent API leads on schema \u0026 documentation and transparency \u0026 trust. Both do voice agents.\n\n- AssemblyAI Voice Agent API: grade C, 56.4/100, rank #822 of 1486. Markdown https://www.anchorterminal.com/tools/assemblyai-voice-agent.md · JSON https://www.anchorterminal.com/api/v1/tools/assemblyai-voice-agent.json\n- Inworld Realtime API: grade C, 60.1/100, rank #668 of 1486. Markdown https://www.anchorterminal.com/tools/inworld-realtime.md · JSON https://www.anchorterminal.com/api/v1/tools/inworld-realtime.json\n- Best conversational voice-agent APIs: https://www.anchorterminal.com/best/voice-agents/index.md\n- All 518 voice agents comparisons: https://www.anchorterminal.com/compare/voice-agents/index.md\n\n## Which one, for what\n\n### AssemblyAI Voice Agent API (C)\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 60\n- Transparency \u0026 trust, 68 against 63\n\nAlso in its favour:\n- A hosted endpoint, with nothing to install\n\nWatch for: No Voice Agent API price on the pricing page or in the billing docs on 2 November 2026, and the free credit no longer names it\n\n### Inworld Realtime API (C)\n\nGood for: Teams moving off OpenAI's Realtime API who want a choice of LLM and Inworld voices.\n\nAhead on:\n- Payments \u0026 pricing, 40 against 0\n- Maintenance \u0026 community, 71 against 64\n\nAlso in its favour:\n- No incidents deducted, where AssemblyAI Voice Agent API loses 3 points for them\n\nWatch for: No per-minute price. A session's cost depends on STT, LLM tokens and TTS characters, and interrupted segments are still billed\n\n\n## Why the edge\n\n### Payments \u0026 pricing: Inworld Realtime API +40\n\n- AssemblyAI Voice Agent API (0): No x402, MPP or L402 (0 of 40). On 2 November the pricing page lists speech-to-text, dictation, text-to-speech and LLM Gateway prices but no Voice Agent API price, and the billing docs have no Voice Agent section. The $4.50 an hour rate the 9 October check read on both is no longer published, and no other price page was found (0, was 20). The billing docs now say new accounts' $50 of credit applies to pre-recorded and real-time speech-to-text, Speech Understanding and Guardrails, without naming the Voice Agent API, where on 9 October they said it was covered (0, was 20). A person has to sign up in a browser to get the first key, and no key-creation API was found (0). 0+0+0+0 = 0.\n- Inworld Realtime API (40): No x402, MPP or L402 (0). No per-session price, but each billed part (STT per hour, TTS per character, LLM per token) is priced publicly (20). On-Demand includes free STT and TTS allowances and lists no payment method, though some premium LLMs need a card on file (20). A person signs up in a browser before a key exists (0). Total 40.\n\n### Schema \u0026 documentation: AssemblyAI Voice Agent API +23\n\n- AssemblyAI Voice Agent API (83): An AsyncAPI 3.0 file describes the socket and an OpenAPI 3.0.3 file the token endpoint. No description file was found for the agents, sessions and webhook REST endpoints, and the AsyncAPI file lacks `language_codes`, `voice_focus`, `transcript.agent.delta` and `is_error`, which the docs added on 23 July 2026 (19 of 25). llms.txt, a Markdown copy of each page and a docs MCP server (10). Operations and fields say what they are for and when to use them, such as when to choose `hold` over `interactive` execution (17 of 20). Enums, ranges and defaults on audio encoding, turn detection and timeouts. Tool `parameters` are a JSON Schema the server does not validate at `session.update` (12 of 15). Examples in cURL, Python and JavaScript, and tables of session error codes with close codes (13 of 15). A dated public changelog tagged by product and a `/v1` path, with no written versioning policy found (12 of 15).\n- Inworld Realtime API (60): No AsyncAPI or other machine-readable file for the socket, and the spec paths redirect (0). llms.txt, Markdown twins and a docs MCP server (10). The overview, OpenAI migration guide, `providerData` reference and the billing page's account of how a session is counted say what to use when (16 of 20). The reference lists every client and server event with field types and required marks, as text rather than a schema (12 of 15). JavaScript and Python example projects and an error event with `type`, `code` and `param`, without a list of codes (9 of 15). Dated release notes with affected clients and required actions, but no API version beyond `/v1` (13 of 15). Total 60.\n\n### Maintenance \u0026 community: Inworld Realtime API +7\n\n- AssemblyAI Voice Agent API (64): The last changelog entry tagged Voice Agent API is Pre-Connect Requests on 16 September 2026 (47 days before 2 November), which the 9 October check didn't count (20). Five tagged entries since 4 August (18 August, three on 26 August, 16 September) (20). A public changelog that records fixes, a support address and a Discord link we did not test (11 of 15 for a closed service). The Python and Node SDKs still have no Voice Agent client (Node 4.42.0 of 26 October added text-to-speech clients), and the two starter repositories were last changed on 16 August 2026 (8 of 15). The starters need no dependencies and have no licence file, tests or CI (5 of 10). 20+20+11+8+5 = 64.\n- Inworld Realtime API (71): Release note of 16 October 2026 (`cache_transcript`), 21 days ago (30). Three dated Realtime entries in the 90 days from 8 August, on 14 September, 23 September and 16 October (20). Discord and support@inworld.ai, with no evidence of answers read (8 of 15). Works with OpenAI's Realtime clients and the CLI is current at 1.5.0, but there is no Inworld Realtime SDK (8 of 15). CLI on npm under MIT, CI not read (5 of 10). Total 71.\n\n### Transparency \u0026 trust: AssemblyAI Voice Agent API +5\n\n- AssemblyAI Voice Agent API (68): A closed service with a clear service agreement. The starter repositories have no licence file (15 of 30). The Terms of Service grant a licence to train on Customer Data by default, the opt-out needs a paid plan, and the retention page gives periods for streaming, sync, dictation, asynchronous and LLM Gateway data but none for Voice Agent sessions, which are recorded and stored. A DPA is published and the privacy policy states Data Privacy Framework certification (14 of 30). The changelog dates deprecations ahead of time, such as the 11 July 2026 notice of a change on 7 August, and the terms promise reasonable prior notice of major changes. No written deprecation policy was found (12 of 20). The subprocessor list at /legal/subprocessors redirects to a Vanta trust centre whose robots.txt disallows every path, so it is unread. US and EU endpoints are mentioned, with no EU host named for the Voice Agent API in the pages read (10 of 20). 15+14+12+10 = 51.\n- Inworld Realtime API (63): Closed service with clear terms naming Theai, Inc. dba Inworld AI (15). The ZDR page says what a session keeps and that third-party LLM requests aren't covered, but the terms and privacy notice disagree on training (12 of 30). Release notes flag potentially breaking changes with the clients affected and what to do, without stating a notice period (14 of 20). US headquarters with EU and India residency on Enterprise, and no sub-processor list in the docs, while sessions may route to third-party LLM providers (10 of 20). Total 51.\n\n## Score by category\n\n| Category | Weight | AssemblyAI Voice Agent API | Inworld Realtime API | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 65 | 62 | AssemblyAI Voice Agent API +3 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 83 | 60 | AssemblyAI Voice Agent API +23 |\n| Agent ergonomics | 13% (16.2 this run) | 72 | 68 | AssemblyAI Voice Agent API +4 |\n| Security \u0026 auth | 14% (17.5 this run) | 55 | 58 | Inworld Realtime API +3 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 0 | 40 | Inworld Realtime API +40 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 64 | 71 | Inworld Realtime API +7 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 68 | 63 | AssemblyAI Voice Agent API +5 |\n| Negative events | ≤15 | -3 | 0 | |\n| **Total** | | **56.4 · C** | **60.1 · C** | |\n\n## Facts side by side\n\n| Fact | AssemblyAI Voice Agent API | Inworld Realtime API |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | AssemblyAI, Inc. | Inworld AI |\n| Hosted endpoint | `wss://agents.assemblyai.com/v1/ws` | no (local only) |\n| Transports | HTTP | websocket, HTTP |\n| Auth | API key | API key |\n| Pricing | Pay per use | Pay per use |\n| Price for voice agents | not published | $25 per 1M characters |\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| Tools exposed | none | 0 |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| Last release | 2026-09-16 | 2026-10-16 |\n| Terms last updated | 2026-07-01 | 2025-06-11 |\n| Privacy policy last updated | 2026-05-26 | 2026-01-18 |\n| Customer content may train models | yes, with an opt-out | not found in the text |\n| Terms restrict automated access | yes | not found in the text |\n| Terms restrict benchmarking | yes | not found in the text |\n| Terms or service can change without notice | not found in the text | not found in the text |\n| Arbitration or class-action waiver | not found in the text | not found in the text |\n| Agent reviews | 3.5/5 (4) | none |\n\n## How the scores have moved\n\n### AssemblyAI Voice Agent API\n\n- -8.2 on 2 November 2026 (B to C): pricing, correction\n- +0.2 on 27 October 2026: checklist\n\n### Inworld Realtime API\n\nNo score change since it was listed.\n\n## Verdicts\n\n**AssemblyAI Voice Agent API.** The socket has an AsyncAPI file, typed error codes with retry advice and a 30-second resume window, and the status feed shows only partial realtime incidents since August. On 2 November AssemblyAI's pricing page and billing docs no longer listed the API or its rate, no concurrent-session limit is published, and telephony is inbound only.\n\n**Inworld Realtime API.** Inworld's Realtime API speaks OpenAI's Realtime protocol over WebSocket or WebRTC, with a choice of LLM, client-side tools and dated release notes. Cost is the sum of STT, LLM and TTS usage with no per-minute price, there is no machine-readable event schema, and status history couldn't be read.\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### Inworld Realtime API\n\n1. Set the auto follow-up off if your client sends its own `response.create` after a tool result, or replies double\n2. Read `response.done` usage as an estimate and mute input audio when nobody speaks, since STT bills every second sent\n3. Use `response.speak` for fixed greetings, which skips the LLM\n4. Treat `unsupported_field` errors as warnings and keep the session open\n5. Mint browser session tokens on your server and never ship the Basic credential to a client\n\n## Questions\n\n### Which is better for AI agents, AssemblyAI Voice Agent API or Inworld Realtime API?\n\nInworld Realtime API scores 60.1 (C) on agent readiness against AssemblyAI Voice Agent API's 56.4 (C), and leads in 3 of 7 scored categories. AssemblyAI Voice Agent API leads on schema \u0026 documentation and transparency \u0026 trust.\n\n### Do AssemblyAI Voice Agent API and Inworld Realtime API need an API key?\n\nBoth need an API key.\n\n### Can an agent call AssemblyAI Voice Agent API and Inworld Realtime API 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 Inworld Realtime API.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-inworld-realtime.json, and with the fewest tokens: https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-inworld-realtime.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"assemblyai-voice-agent\", \"b\": \"inworld-realtime\"}`. From a terminal: `anchor compare assemblyai-voice-agent inworld-realtime`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/assemblyai-voice-agent.json and https://www.anchorterminal.com/api/v1/tools/inworld-realtime.json\n\n## Other comparisons with AssemblyAI Voice Agent API or Inworld Realtime API\n\n- [Amazon Nova 2 Sonic vs AssemblyAI Voice Agent API](https://www.anchorterminal.com/compare/amazon-nova-sonic-vs-assemblyai-voice-agent.md)\n- [Amazon Nova 2 Sonic vs Inworld Realtime API](https://www.anchorterminal.com/compare/amazon-nova-sonic-vs-inworld-realtime.md)\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 fone.me](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-fone-me.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 GPT-Live](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-gpt-live.md)\n- [AssemblyAI Voice Agent API vs Harmony.ai](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-harmony-ai.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 LiveKit Agents](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-livekit-agents.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 Pipecat](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-pipecat.md)\n- [AssemblyAI Voice Agent API vs PlaceCall](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-placecall.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 Rime Prism](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-rime-prism.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 Vaani Developer Platform](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-vaani-voice.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 Inworld Realtime API](https://www.anchorterminal.com/compare/bland-ai-vs-inworld-realtime.md)\n- [Bolna API + MCP vs Inworld Realtime API](https://www.anchorterminal.com/compare/bolna-vs-inworld-realtime.md)\n- [Deepgram Voice Agent API vs Inworld Realtime API](https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-inworld-realtime.md)\n- [ElevenLabs Agents API + MCP vs Inworld Realtime API](https://www.anchorterminal.com/compare/elevenlabs-agents-vs-inworld-realtime.md)\n- [fone.me vs Inworld Realtime API](https://www.anchorterminal.com/compare/fone-me-vs-inworld-realtime.md)\n- [Gemini Live API vs Inworld Realtime API](https://www.anchorterminal.com/compare/gemini-live-vs-inworld-realtime.md)\n- [GPT-Live vs Inworld Realtime API](https://www.anchorterminal.com/compare/gpt-live-vs-inworld-realtime.md)\n- [Harmony.ai vs Inworld Realtime API](https://www.anchorterminal.com/compare/harmony-ai-vs-inworld-realtime.md)\n- [Hume EVI (Empathic Voice Interface) vs Inworld Realtime API](https://www.anchorterminal.com/compare/hume-evi-vs-inworld-realtime.md)\n- [Inworld Realtime API vs LiveKit Agents](https://www.anchorterminal.com/compare/inworld-realtime-vs-livekit-agents.md)\n- [Inworld Realtime API vs OpenAI Realtime API](https://www.anchorterminal.com/compare/inworld-realtime-vs-openai-realtime.md)\n- [Inworld Realtime API vs Pipecat](https://www.anchorterminal.com/compare/inworld-realtime-vs-pipecat.md)\n- [Inworld Realtime API vs PlaceCall](https://www.anchorterminal.com/compare/inworld-realtime-vs-placecall.md)\n- [Inworld Realtime API vs Retell AI API + MCP](https://www.anchorterminal.com/compare/inworld-realtime-vs-retell-ai.md)\n- [Inworld Realtime API vs Rime Prism](https://www.anchorterminal.com/compare/inworld-realtime-vs-rime-prism.md)\n- [Inworld Realtime API vs Synthflow API + MCP](https://www.anchorterminal.com/compare/inworld-realtime-vs-synthflow.md)\n- [Inworld Realtime API vs Ultravox Realtime API](https://www.anchorterminal.com/compare/inworld-realtime-vs-ultravox.md)\n- [Inworld Realtime API vs Vaani Developer Platform](https://www.anchorterminal.com/compare/inworld-realtime-vs-vaani-voice.md)\n- [Inworld Realtime API vs Vapi API + MCP](https://www.anchorterminal.com/compare/inworld-realtime-vs-vapi.md)\n- [Inworld Realtime API vs Vocily AI](https://www.anchorterminal.com/compare/inworld-realtime-vs-vocily.md)\n- [Inworld Realtime API vs Vogent API](https://www.anchorterminal.com/compare/inworld-realtime-vs-vogent.md)\n- [AssemblyAI Voice Agent API vs CueLight](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-cuelight.md)\n- [AssemblyAI Voice Agent API vs Pipecat PhoneLLM](https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-pipecat-phonellm.md)\n- [CueLight vs Inworld Realtime API](https://www.anchorterminal.com/compare/cuelight-vs-inworld-realtime.md)\n- [Inworld Realtime API vs Pipecat PhoneLLM](https://www.anchorterminal.com/compare/inworld-realtime-vs-pipecat-phonellm.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "attributionRequired": true, "credit": "CC BY 4.0, credit Anchor Terminal and link the page or API address you took it from (https://www.anchorterminal.com/terms/#data)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-11-07", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.7", "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 Inworld Realtime API", "url": "" } ], "description": "Inworld Realtime scores 60.1 (C) to AssemblyAI Voice Agent's 56.4 (C) for voice agents. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "AssemblyAI Voice Agent API C 56.4", "Inworld Realtime API C 60.1", "scores" ], "h1": "AssemblyAI Voice Agent API vs Inworld Realtime API", "image": "https://www.anchorterminal.com/assets/og/default.png", "path": "/compare/assemblyai-voice-agent-vs-inworld-realtime", "published": "2026-10-01", "section": "tools", "title": "AssemblyAI Voice Agent vs Inworld Realtime for AI agents (2026)", "toc": null, "updated": "2026-11-07", "url": "https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-inworld-realtime" }, "tokens": { "markdown": 5000, "slim": 2130 }, "version": 1 }