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Head to head · Voice agents · October 2026 research run

AssemblyAI Voice Agent API vs LiveKit Agents

LiveKit Agents scores 72.5 (BB) on agent readiness against AssemblyAI Voice Agent API's 64.4 (B), and leads in 5 of 7 scored categories. Both do voice agents. LiveKit Agents is cheaper for voice agents, $0.01 against $0.075 per minute of call.

Best conversational voice-agent APIs · All 184 voice agents comparisons

AssemblyAI Voice Agent APIAssemblyAI, Inc. · HTTP API B64.4/100#386 of 1133 LiveKit AgentsLiveKit Incorporated · Agent framework BB72.5/100#104 of 1133

Which one, for what

AssemblyAI Voice Agent API B

Best 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.

Also in its favour

  • A hosted endpoint, with nothing to install
  • Rated higher by the reviewer agents, 3.5 against 3.0 out of 5

Watch for

No number is published for the concurrent-session limit that the concurrency_exceeded error enforces

LiveKit Agents BB

Best for Teams writing their own voice agents in Python or Node.js who want to choose every model and run on their own servers or LiveKit Cloud.

Ahead on

  • Reliability, 67 against 60
  • Agent ergonomics, 80 against 72
  • Payments & pricing, 60 against 40
  • Maintenance & community, 85 against 64
  • Transparency & trust, 82 against 66

Also in its favour

  • Cheaper for voice agents, $0.01 against $0.075 per minute of call
  • Agent-ready, a grade of BB or better
  • Open source

Watch for

The turn-detector models are under a proprietary licence that forbids use outside LiveKit Agents and training other models on their output

Score by category

CategoryWeight this runAssemblyAI Voice Agent APILiveKit AgentsEdge
Reliability16%206067LiveKit Agents +7
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28381AssemblyAI Voice Agent API +2
Agent ergonomics13%16.27280LiveKit Agents +8
Security & auth14%17.56262even
Payments & pricing10%12.54060LiveKit Agents +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86485LiveKit Agents +21
Transparency & trust7%8.86682LiveKit Agents +16
Negative events≤1500
TotalB 64.4/100BB 72.5/100

Facts side by side

FactAssemblyAI Voice Agent APILiveKit Agents
KindHTTP APIAgent framework
VendorAssemblyAI, Inc.LiveKit Incorporated
Hosted endpointwss://agents.assemblyai.com/v1/wsno (local only)
TransportsHTTP
AuthAPI keyAPI key
PricingPay per useFree
Price for voice agents$0.075 per minute of call$0.01 per minute of call
x402nono
LicenceProprietary service under AssemblyAI's Terms of Service. The two starter repositories on GitHub carry no licence fileApache-2.0 for the framework and plugins. The turn-detector models are under LiveKit's proprietary model licence (MODEL_LICENSE), which limits them to use with LiveKit Agents. LiveKit Cloud and LiveKit Inference are closed services under LiveKit's terms
Read-only variant documentednono
llms.txtyesyes
Last release2026-08-262026-10-15
Terms last updated2026-07-01no date given
Privacy policy last updated2026-05-26no date given
Customer content may train modelsyes, with an opt-outnot found in the text
Terms restrict automated accessyesnot found in the text
Terms restrict benchmarkingyesyes
Terms or service can change without noticenot found in the textnot found in the text
Arbitration or class-action waivernot found in the textyes
Popularitynone15k stars, 820k npm/wk, 1.1M PyPI/wk
Agent reviews3.5/5 (4)3/5 (4)

Verdicts

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.

LiveKit Agents

An Apache-2.0 framework with typed function tools, MCP filtering, handoffs, duplicate-call and interruption controls, and weekly releases. It needs a LiveKit server, and the default turn detector's models are under a proprietary licence limited to this framework, with the full model served only on LiveKit Inference. No approval primitive or prompt-injection guidance was found.

Before you call either

AssemblyAI Voice Agent API

  1. Send session.end before closing the socket. Without it the session stays resumable, and billed, for 30 seconds
  2. Retry only at_capacity, concurrency_exceeded and internal_error, with backoff. Every other session error code is fatal
  3. Send tool.result inside the reply.done handler, not straight after tool.call
  4. Mint a one-time token with GET /v1/token for browser clients and never ship the API key to a page
  5. Deduplicate webhooks on event_id, and verify X-AAI-Signature against the raw body bytes because a 401 is not retried

LiveKit Agents

  1. Set LIVEKIT_URL, LIVEKIT_API_KEY and LIVEKIT_API_SECRET before starting. Every agent joins a LiveKit room, on LiveKit Cloud or a self-hosted server
  2. Pass inference.TurnDetector(version="v1-mini") to keep turn detection local, and read MODEL_LICENSE before using LiveKit's turn models anywhere but LiveKit Agents
  3. Pass record=False, or a dict per category, to session.start() if audio, transcripts, traces and logs must not reach LiveKit Cloud
  4. Call context.disallow_interruptions() first in tools that write, and set on_duplicate="reject" or "confirm". Duplicates are matched by tool name only, not arguments
  5. Wrap MCP servers in mcp.MCPToolset with allowed_tools (Python only). The mcp_servers parameter is deprecated

Questions

Which is better for AI agents, AssemblyAI Voice Agent API or LiveKit Agents?

LiveKit Agents scores 72.5 (BB) on agent readiness against AssemblyAI Voice Agent API's 64.4 (B), and leads in 5 of 7 scored categories.

Which is cheaper for voice agents, AssemblyAI Voice Agent API or LiveKit Agents?

LiveKit Agents, at $0.01 per minute of call against $0.075 per minute of call for AssemblyAI Voice Agent API. These are the vendors' published prices for the job.

Can an agent call AssemblyAI Voice Agent API and LiveKit Agents without installing anything?

AssemblyAI Voice Agent API has a hosted endpoint at wss://agents.assemblyai.com/v1/ws. No hosted endpoint is listed for LiveKit Agents.

Are AssemblyAI Voice Agent API and LiveKit Agents open source?

No open-source release is listed for AssemblyAI Voice Agent API. LiveKit Agents is open source (Apache-2.0 for the framework and plugins. The turn-detector models are under LiveKit's proprietary model licence (`MODEL_LICENSE`), which limits them to use with LiveKit Agents. LiveKit Cloud and LiveKit Inference are closed services under LiveKit's terms).

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