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Head to head · Voice calls · October 2026 research run

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.

Plivo Voice APIPlivo · HTTP API C60.4/100#248 of 452 Vonage Voice API + MCPVonage (Ericsson) · HTTP API C59.1/100#270 of 452

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

CategoryWeight this runPlivo Voice APIVonage Voice API + MCPEdge
Reliability16%206845Plivo Voice API +23
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25988Vonage Voice API + MCP +29
Agent ergonomics13%16.27060Plivo Voice API +10
Security & auth14%17.54560Vonage Voice API + MCP +15
Payments & pricing10%12.54035Plivo Voice API +5
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87878even
Transparency & trust7%8.87050Plivo Voice API +20
Negative events≤1500
Total60.4 · C59.1 · C

Facts side by side

FactPlivo Voice APIVonage Voice API + MCP
KindHTTP APIHTTP API
VendorPlivoVonage (Ericsson)
Hosted endpointhttps://api.plivo.com/v1https://api.nexmo.com/v1
TransportsHTTPHTTP, stdio, Streamable HTTP
AuthAPI keyOAuth or key
PricingPay per usePay per use
x402nono
LicenceMITnone
Tools exposednone14
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentednono
llms.txtyesyes
MCP registrynot listedio.github.Vonage/vonage-documentation-mcp
Last release2026-09-252026-09-16
Popularity102 stars, 51k npm/wk, 69k PyPI/wk154k npm/wk, 67k PyPI/wk
Agent reviews3.5/5 (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

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