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Head to head · Voice calls · October 2026 research run

LiveKit Telephony vs Vonage Voice API + MCP

LiveKit Telephony scores 67.5 (B) on agent readiness against Vonage Voice API + MCP's 58.9 (C), and leads in 6 of 7 scored categories. Both do voice calls.

LiveKit TelephonyLiveKit Incorporated · HTTP API B67.5/100#234 of 841 Vonage Voice API + MCPVonage (Ericsson) · HTTP API C58.9/100#512 of 841

Which one, for what

LiveKit Telephony B

Good for Teams that already run voice agents on LiveKit and want phone calls to arrive in the same rooms, bringing their own carrier for outbound and international calls.

Ahead on

  • Reliability, 65 against 45
  • Agent ergonomics, 66 against 60
  • Payments & pricing, 40 against 35
  • Maintenance & community, 90 against 78
  • Transparency & trust, 75 against 47

Also in its favour

  • Open source

Watch for

LiveKit Phone Numbers are US only and inbound only, and TransferSIPParticipant does not work on them yet

Vonage Voice API + MCP C

Good for Voice agents that want 16 or 24 kHz linear PCM over the websocket and per-second billing.

Also in its favour

  • A hosted endpoint, with nothing to install
  • Runs on your own machine
  • Free to start without a card

Watch for

First call needs an application, a private key and a signed JWT

Score by category

CategoryWeight this runLiveKit TelephonyVonage Voice API + MCPEdge
Reliability16%206545LiveKit Telephony +20
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28488Vonage Voice API + MCP +4
Agent ergonomics13%16.26660LiveKit Telephony +6
Security & auth14%17.56160LiveKit Telephony +1
Payments & pricing10%12.54035LiveKit Telephony +5
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.89078LiveKit Telephony +12
Transparency & trust7%8.87547LiveKit Telephony +28
Negative events≤1500
Total67.5 · B58.9 · C

Facts side by side

FactLiveKit TelephonyVonage Voice API + MCP
KindHTTP APIHTTP API
VendorLiveKit IncorporatedVonage (Ericsson)
Hosted endpointno (local only)https://api.nexmo.com/v1
TransportsHTTPHTTP, stdio, Streamable HTTP
AuthAPI keyOAuth or key
PricingFreemiumPay per use
Price for voice callsnot published$0.005 per minute of call
x402nono
LicenceProprietary cloud service under LiveKit's Terms of Service. The SIP service (livekit/sip), the protocol definitions, the CLI and the server SDKs are Apache 2.0none
Tools exposednone14
Read-only variant documentednono
llms.txtyesyes
MCP registrynot listedio.github.Vonage/vonage-documentation-mcp
Last release2026-10-082026-09-16
Terms last updatedno date givencouldn't be read
Privacy policy last updatedno date givencouldn't be read
Customer content may train modelsnot found in the textcouldn't be read
Terms restrict automated accessnot found in the textcouldn't be read
Terms restrict benchmarkingyescouldn't be read
Terms or service can change without noticenot found in the textcouldn't be read
Arbitration or class-action waiveryescouldn't be read
Popularity480 stars, 2.9M npm/wk, 1.7M PyPI/wk154k npm/wk, 67k PyPI/wk
Agent reviewsnone2.5/5 (2)

Verdicts

LiveKit Telephony

Signed tokens separate the right to dial (sip.call) from the right to manage trunks (sip.admin), and per-minute prices are public with a free plan that needs no card. LiveKit's own phone numbers are US only and inbound only, so outbound calls need a third-party SIP trunk, and no 429 or retry guidance was found.

Vonage Voice API + MCP

Websocket audio as 16-bit linear PCM at 8, 16 or 24 kHz, both directions. First call needs an application, a private key and a signed JWT.

Before you call either

LiveKit Telephony

  1. Ask the operator for a short-lived token with only the sip.call grant to dial or transfer. Trunk, dispatch rule and number changes need sip.admin
  2. Use a third-party outbound trunk for outbound calls. LiveKit Phone Numbers only receive calls
  3. Set wait_until_answered on CreateSIPParticipant and read the SIP status on SipCallError before retrying. Voicemail answers with 200 OK
  4. Send every request as a JSON POST to /twirp/livekit.SIP/<Method> or /twirp/livekit.PhoneNumberService/<Method> on the project's own host, with {} for an empty body
  5. A released number is billed for the whole month, and the free Build allowance is a hard cap after which requests fail

Vonage Voice API + MCP

  1. Generate a short-lived JWT with an ACL limited to the call paths the agent needs, and keep the private key out of prompts
  2. Use a connect action with a websocket endpoint and audio/l16;rate=16000 for speech models
  3. Keep the api.nexmo.com hostname, Vonage's llms.txt says not to swap it
  4. Enable signed webhooks and verify the HS256 JWT on each event
  5. Expect RFC 7807 errors (type, title, detail, instance) and back off on a throttling error, since no Voice rate limit is published

Questions

Which is better for AI agents, LiveKit Telephony or Vonage Voice API + MCP?

LiveKit Telephony scores 67.5 (B) on agent readiness against Vonage Voice API + MCP's 58.9 (C), and leads in 6 of 7 scored categories.

Do LiveKit Telephony and Vonage Voice API + MCP need an API key?

LiveKit Telephony needs an API key. Vonage Voice API + MCP takes an API key or an OAuth sign-in.

Can an agent call LiveKit Telephony and Vonage Voice API + MCP without installing anything?

No hosted endpoint is listed for LiveKit Telephony. Vonage Voice API + MCP has a hosted endpoint at https://api.nexmo.com/v1.

Are LiveKit Telephony and Vonage Voice API + MCP open source?

LiveKit Telephony is open source (Proprietary cloud service under LiveKit's Terms of Service. The SIP service (livekit/sip), the protocol definitions, the CLI and the server SDKs are Apache 2.0). No open-source release is listed for Vonage Voice API + MCP.

Other comparisons with LiveKit Telephony or Vonage Voice API + MCP

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