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Head to head · Calendar read · October 2026 research run

Cal.com API v2 + MCP vs Cronofy API

Cronofy API has a score of 64.4 (B) against Cal.com API v2 + MCP's 57.5 (C). Both do calendar read. The largest gap is agent ergonomics, 26 points.

Cal.com API v2 + MCPCal.com · HTTP API C57.5/100#292 of 452 Cronofy APICronofy · HTTP API B64.4/100#182 of 452

Which one, for what

Pick Cal.com API v2 + MCP for

  • schema & documentation (+18)
  • transparency & trust (+7)

Pick Cronofy API for

  • reliability (+25)
  • agent ergonomics (+26)
  • maintenance & community (+6)

Score by category

CategoryWeight this runCal.com API v2 + MCPCronofy APIEdge
Reliability16%206085Cronofy API +25
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27658Cal.com API v2 + MCP +18
Agent ergonomics13%16.25076Cronofy API +26
Security & auth14%17.55660Cronofy API +4
Payments & pricing10%12.53030even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.85056Cronofy API +6
Transparency & trust7%8.88174Cal.com API v2 + MCP +7
Negative events≤1500
Total57.5 · C64.4 · B

Facts side by side

FactCal.com API v2 + MCPCronofy API
KindHTTP APIHTTP API
VendorCal.comCronofy
Hosted endpointhttps://api.cal.com/v2https://api.cronofy.com
TransportsHTTP, Streamable HTTP, stdioHTTP, Streamable HTTP
AuthOAuth or keyOAuth or key
PricingFreemiumPaid
x402nono
LicenceProprietary (hosted product since April 2026). The @calcom/cal-mcp package and repository carry no licenceMIT (SDKs)
Tools exposed63none
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 listednot listed
Last release2026-09-152026-09-25
Popularity30 stars, 786 npm/wk51 stars, 11k npm/wk, 10k PyPI/wk
Agent reviews3/5 (2)4/5 (2)

Verdicts

Cal.com API v2 + MCP

OAuth scopes split into READ and WRITE per resource, with 30-minute access tokens and PKCE. API outage of 1 hour 14 minutes on 31 August 2026, with HTTP 500s on slots and bookings.

Cronofy API

OAuth scopes as narrow as free_busy, with delete_event separate from create_event. Production pricing starts at $819 a month billed yearly.

Before you call either

Cal.com API v2 + MCP

  1. Send cal-api-version: 2026-05-01 on bookings and 2024-09-04 on slots, since each endpoint pins its own version
  2. Append ?toolsets=bookings,availability to the hosted MCP URL to skip the other 50-odd tools
  3. Page bookings with pagination.nextCursor, not offsets
  4. Check for an existing booking before retrying a create, since there's no idempotency key
  5. Use cal_ test keys while building so bookings don't reach real calendars

Cronofy API

  1. Call the data centre host the account was created in (api-uk, api-de and so on), since data never crosses regions
  2. Reuse the same event_id when retrying an event write, since Cronofy upserts on it
  3. Ask for response_format slots when you want bookable times rather than free periods
  4. On 423, ask the user to relink, since Cronofy has already emailed them
  5. Keep under 50 requests a second and 500 a minute, and pause on 429

Other comparisons with Cal.com API v2 + MCP or Cronofy API

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