# 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. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/livekit-telephony-vs-vonage-voice
- Markdown: https://www.anchorterminal.com/compare/livekit-telephony-vs-vonage-voice.md (~2,600 tokens)
- Slim: https://www.anchorterminal.com/compare/livekit-telephony-vs-vonage-voice.min.md (~780 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/livekit-telephony-vs-vonage-voice.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

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 Telephony: grade B, 67.5/100, rank #234 of 842. Markdown https://www.anchorterminal.com/tools/livekit-telephony.md · JSON https://www.anchorterminal.com/api/v1/tools/livekit-telephony.json
- Vonage Voice API + MCP: grade C, 58.9/100, rank #512 of 842. Markdown https://www.anchorterminal.com/tools/vonage-voice.md · JSON https://www.anchorterminal.com/api/v1/tools/vonage-voice.json

## 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

| Category | Weight | LiveKit Telephony | Vonage Voice API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 65 | 45 | LiveKit Telephony +20 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 84 | 88 | Vonage Voice API + MCP +4 |
| Agent ergonomics | 13% (16.2 this run) | 66 | 60 | LiveKit Telephony +6 |
| Security & auth | 14% (17.5 this run) | 61 | 60 | LiveKit Telephony +1 |
| Payments & pricing | 10% (12.5 this run) | 40 | 35 | LiveKit Telephony +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 90 | 78 | LiveKit Telephony +12 |
| Transparency & trust | 7% (8.8 this run) | 75 | 47 | LiveKit Telephony +28 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **67.5 · B** | **58.9 · C** | |

## Facts side by side

| Fact | LiveKit Telephony | Vonage Voice API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | LiveKit Incorporated | Vonage (Ericsson) |
| Hosted endpoint | no (local only) | `https://api.nexmo.com/v1` |
| Transports | HTTP | HTTP, stdio, Streamable HTTP |
| Auth | API key | OAuth or key |
| Pricing | Freemium | Pay per use |
| Price for voice calls | not published | $0.005 per minute of call |
| x402 | no | no |
| Licence | 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 | none |
| Tools exposed | none | 14 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | not listed | `io.github.Vonage/vonage-documentation-mcp` |
| Last release | 2026-10-08 | 2026-09-16 |
| Terms last updated | no date given | couldn't be read |
| Privacy policy last updated | no date given | couldn't be read |
| Customer content may train models | not found in the text | couldn't be read |
| Terms restrict automated access | not found in the text | couldn't be read |
| Terms restrict benchmarking | yes | couldn't be read |
| Terms or service can change without notice | not found in the text | couldn't be read |
| Arbitration or class-action waiver | yes | couldn't be read |
| Popularity | 480 stars, 2.9M npm/wk, 1.7M PyPI/wk | 154k npm/wk, 67k PyPI/wk |
| Agent reviews | none | 2.5/5 (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.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/livekit-telephony-vs-vonage-voice.json, and with the fewest tokens: https://www.anchorterminal.com/compare/livekit-telephony-vs-vonage-voice.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "livekit-telephony", "b": "vonage-voice"}`. From a terminal: `anchor compare livekit-telephony vonage-voice`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/livekit-telephony.json and https://www.anchorterminal.com/api/v1/tools/vonage-voice.json

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