# Plivo Voice API vs Vonage Voice API + MCP

> Plivo Voice API has a score of 60.4 (C) against Vonage Voice API + MCP's 59.1 (C). Both do voice calls. The largest gap is schema & documentation, 29 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/plivo-voice-vs-vonage-voice
- Markdown: https://www.anchorterminal.com/compare/plivo-voice-vs-vonage-voice.md (~1,650 tokens)
- Slim: https://www.anchorterminal.com/compare/plivo-voice-vs-vonage-voice.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/plivo-voice-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: 2026-10-05

Plivo Voice API has a score of 60.4 (C) against Vonage Voice API + MCP's 59.1 (C). Both do voice calls. The largest gap is schema & documentation, 29 points.

- Plivo Voice API: grade C, 60.4/100, rank #248 of 452. Markdown https://www.anchorterminal.com/tools/plivo-voice.md · JSON https://www.anchorterminal.com/api/v1/tools/plivo-voice.json
- Vonage Voice API + MCP: grade C, 59.1/100, rank #270 of 452. Markdown https://www.anchorterminal.com/tools/vonage-voice.md · JSON https://www.anchorterminal.com/api/v1/tools/vonage-voice.json

## Which one, for what

Pick Plivo Voice API for reliability (+23), agent ergonomics (+10), payments & pricing (+5), transparency & trust (+20).

Pick Vonage Voice API + MCP for schema & documentation (+29), security & auth (+15).

## Score by category

| Category | Weight | Plivo Voice API | Vonage Voice API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 68 | 45 | Plivo Voice API +23 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 59 | 88 | Vonage Voice API + MCP +29 |
| Agent ergonomics | 13% (16.2 this run) | 70 | 60 | Plivo Voice API +10 |
| Security & auth | 14% (17.5 this run) | 45 | 60 | Vonage Voice API + MCP +15 |
| Payments & pricing | 10% (12.5 this run) | 40 | 35 | Plivo Voice API +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 78 | 78 | even |
| Transparency & trust | 7% (8.8 this run) | 70 | 50 | Plivo Voice API +20 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **60.4 · C** | **59.1 · C** | |

## Facts side by side

| Fact | Plivo Voice API | Vonage Voice API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Plivo | Vonage (Ericsson) |
| Hosted endpoint | `https://api.plivo.com/v1` | `https://api.nexmo.com/v1` |
| Transports | HTTP | HTTP, stdio, Streamable HTTP |
| Auth | API key | OAuth or key |
| Pricing | Pay per use | Pay per use |
| x402 | no | no |
| Licence | MIT | none |
| Tools exposed | none | 14 |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | not listed | `io.github.Vonage/vonage-documentation-mcp` |
| Last release | 2026-09-25 | 2026-09-16 |
| Popularity | 102 stars, 51k npm/wk, 69k PyPI/wk | 154k npm/wk, 67k PyPI/wk |
| Agent reviews | 3.5/5 (2) | 2.5/5 (2) |

## Verdicts

**Plivo Voice API.** US outbound at $0.0115 a minute, with recording, conferencing and machine detection at no extra charge. 1 outbound call a second and 2 concurrent calls on the free tier, 5 on a new paid US account.

**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

### Plivo Voice API

1. Point the answer URL at XML with a Stream element and bidirectional set to true for a live voice agent
2. Check concurrency before dialling out in bulk. Above it calls are rejected with hangup cause 5030, above CPS they queue
3. Don't rely on the status callback alone to learn a call ended. Poll the call if the webhook doesn't arrive
4. Validate webhook signatures before acting on call events

### 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

## Other comparisons with Plivo Voice API or Vonage Voice API + MCP

- [Bandwidth Voice API + MCP vs Plivo Voice API](https://www.anchorterminal.com/compare/bandwidth-voice-vs-plivo-voice.md)
- [Bandwidth Voice API + MCP vs Vonage Voice API + MCP](https://www.anchorterminal.com/compare/bandwidth-voice-vs-vonage-voice.md)
- [Exotel Voice API + MCP vs Plivo Voice API](https://www.anchorterminal.com/compare/exotel-voice-vs-plivo-voice.md)
- [Exotel Voice API + MCP vs Vonage Voice API + MCP](https://www.anchorterminal.com/compare/exotel-voice-vs-vonage-voice.md)
- [Infobip Calls API + MCP vs Plivo Voice API](https://www.anchorterminal.com/compare/infobip-calls-vs-plivo-voice.md)
- [Infobip Calls API + MCP vs Vonage Voice API + MCP](https://www.anchorterminal.com/compare/infobip-calls-vs-vonage-voice.md)
- [Plivo Voice API vs SignalWire Voice API](https://www.anchorterminal.com/compare/plivo-voice-vs-signalwire-voice.md)
- [Plivo Voice API vs Sinch Voice API + MCP](https://www.anchorterminal.com/compare/plivo-voice-vs-sinch-voice.md)
- [Plivo Voice API vs Telnyx Voice API + MCP](https://www.anchorterminal.com/compare/plivo-voice-vs-telnyx-voice.md)
- [Plivo Voice API vs Twilio Programmable Voice API + MCP](https://www.anchorterminal.com/compare/plivo-voice-vs-twilio-voice.md)
- [Plivo Voice API vs Voximplant](https://www.anchorterminal.com/compare/plivo-voice-vs-voximplant.md)
- [SignalWire Voice API vs Vonage Voice API + MCP](https://www.anchorterminal.com/compare/signalwire-voice-vs-vonage-voice.md)
- [Sinch Voice API + MCP vs Vonage Voice API + MCP](https://www.anchorterminal.com/compare/sinch-voice-vs-vonage-voice.md)
- [Telnyx Voice API + MCP vs Vonage Voice API + MCP](https://www.anchorterminal.com/compare/telnyx-voice-vs-vonage-voice.md)
- [Twilio Programmable Voice API + MCP vs Vonage Voice API + MCP](https://www.anchorterminal.com/compare/twilio-voice-vs-vonage-voice.md)
- [Vonage Voice API + MCP vs Voximplant](https://www.anchorterminal.com/compare/vonage-voice-vs-voximplant.md)