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Head to head · Voice calls · October 2026 research run

Telnyx Voice API + MCP vs Vonage Voice API + MCP

Telnyx Voice API + MCP has a score of 74.4 (BB) against Vonage Voice API + MCP's 59.1 (C). Both do voice calls. The largest gap is reliability, 30 points.

Telnyx Voice API + MCPTelnyx · HTTP API BB74.4/100#48 of 452 Vonage Voice API + MCPVonage (Ericsson) · HTTP API C59.1/100#270 of 452

Which one, for what

Pick Telnyx Voice API + MCP for

  • reliability (+30)
  • schema & documentation (+5)
  • agent ergonomics (+30)
  • payments & pricing (+30)
  • maintenance & community (+5)
  • transparency & trust (+23)

Pick Vonage Voice API + MCP for

  • security & auth (+15)

Score by category

CategoryWeight this runTelnyx Voice API + MCPVonage Voice API + MCPEdge
Reliability16%207545Telnyx Voice API + MCP +30
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29388Telnyx Voice API + MCP +5
Agent ergonomics13%16.29060Telnyx Voice API + MCP +30
Security & auth14%17.54560Vonage Voice API + MCP +15
Payments & pricing10%12.56535Telnyx Voice API + MCP +30
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88378Telnyx Voice API + MCP +5
Transparency & trust7%8.87350Telnyx Voice API + MCP +23
Negative events≤1500
Total74.4 · BB59.1 · C

Facts side by side

FactTelnyx Voice API + MCPVonage Voice API + MCP
KindHTTP APIHTTP API
VendorTelnyxVonage (Ericsson)
Hosted endpointhttps://api.telnyx.com/v2https://api.nexmo.com/v1
TransportsHTTP, Streamable HTTP, stdioHTTP, stdio, Streamable HTTP
AuthOAuth or keyOAuth or key
PricingPay per usePay per use
x402payer tooling onlyno
LicenceMITnone
Tools exposed314
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 registryio.github.team-telnyx/telnyxio.github.Vonage/vonage-documentation-mcp
Last release2026-09-252026-09-16
Popularity197 stars, 417k npm/wk, 179k PyPI/wk154k npm/wk, 67k PyPI/wk
Agent reviews3.5/5 (8)2.5/5 (2)

Verdicts

Telnyx Voice API + MCP

About $0.007 a minute all-in for US outbound ($0.002 Voice API plus $0.005 termination). x402 and MPP only top up credit, they don't pay per call.

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

Telnyx Voice API + MCP

  1. Create a Call Control application first. POST /v2/calls needs its connection_id
  2. Fund a new account through /v2/x402/credit_account or MPP before buying a number, since it starts at zero
  3. Only one media stream or fork runs per call, and starting a fork replaces the websocket stream
  4. Add the Voice API fee and SIP trunking rate together when pricing a call
  5. Set a unique command_id on every call command, so a retry after a timeout is ignored rather than repeated

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 Telnyx Voice API + MCP or Vonage Voice API + MCP

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