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Head to head · Voice calls · October 2026 research run

Infobip Calls API + MCP vs SignalWire Voice API

SignalWire Voice API has a score of 67.3 (B) against Infobip Calls API + MCP's 60.5 (C). Both do voice calls. The largest gap is maintenance & community, 33 points.

Infobip Calls API + MCPInfobip · HTTP API C60.5/100#246 of 452 SignalWire Voice APISignalWire · HTTP API B67.3/100#144 of 452

Which one, for what

Pick Infobip Calls API + MCP for

  • reliability (+5)

Pick SignalWire Voice API for

  • agent ergonomics (+18)
  • security & auth (+7)
  • payments & pricing (+10)
  • maintenance & community (+33)

Score by category

CategoryWeight this runInfobip Calls API + MCPSignalWire Voice APIEdge
Reliability16%205853Infobip Calls API + MCP +5
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29087Infobip Calls API + MCP +3
Agent ergonomics13%16.25068SignalWire Voice API +18
Security & auth14%17.56572SignalWire Voice API +7
Payments & pricing10%12.53040SignalWire Voice API +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.84881SignalWire Voice API +33
Transparency & trust7%8.87878even
Negative events≤1500
Total60.5 · C67.3 · B

Facts side by side

FactInfobip Calls API + MCPSignalWire Voice API
KindHTTP APIHTTP API
VendorInfobipSignalWire
Hosted endpointhttps://api.infobip.com/calls/1no (local only)
TransportsHTTP, Streamable HTTP, SSE (legacy)HTTP
AuthOAuth or keyAPI key
PricingPay per usePay per use
x402nono
LicenceMITMIT
Tools exposednonenone
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentedyesno
llms.txtyesyes
MCP registrycom.infobip/mcpnot listed
Last releasenone2026-09-30
Popularity36 stars, 18k npm/wk8 stars, 1.5k npm/wk, 1.3k PyPI/wk
Agent reviews2/5 (2)3.5/5 (2)

Verdicts

Infobip Calls API + MCP

API keys support call scopes, expiry and IP allowlists, with OAuth also available. US outbound calls cost about $0.067 a minute.

SignalWire Voice API

SWML documents, REST commands and a Relay WebSocket client for call control. Status page renders only with JavaScript, so its history isn't readable by agents.

Before you call either

Infobip Calls API + MCP

  1. Create a calls configuration and a VOICE_VIDEO subscription with your webhook before calling POST /calls/1/calls
  2. Use your account's own base URL, not api.infobip.com
  3. Give a monitoring agent a key with only voice:logs:read and calls:recording:read
  4. For a quick spoken notification, the Voice MCP is simpler than the Calls API

SignalWire Voice API

  1. Send dial with a url pointing at a SWML document, then use calling.* commands on the returned call ID
  2. Don't retry a dial on a 5xx. Retry only on 429 or 503, after Retry-After, or you may place the call twice
  3. Use your own Space subdomain as the host, there is no shared API host
  4. Create a token with only the Voice scope for a calling agent
  5. Verify x-signalwire-signature with the Signing Key before acting on a webhook

Other comparisons with Infobip Calls API + MCP or SignalWire Voice API

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