Calendly API + MCP vs YouCanBookMe API

Calendly API + MCP 86

OpenAPI 3.1 for the scheduling API and a separate one for OAuth, in JSON and YAML (25). llms.txt with about 130 links and Markdown copies of every docs page (10). Reference pages and MCP tool docs mark plan requirements such as paid plan for booking and Teams for routing forms (14). Typed parameters in the spec (12). 400, 401, 403, 404, 409, 424 and 500 responses in the spec. 429 appears on 9 of 65 operations, the contacts endpoints, on 1 November 2026 (12). Dated release notes, latest 30 October 2026. The API version only changes by migration, the last one being v1 to v2 (13).

YouCanBookMe API 10

The reference lives on Stoplight at ycbm.stoplight.io, which usually renders an OpenAPI file, but our reader got only the workspace shell, and no spec file was found at the usual paths; the help centre article on support.youcanbook.me sat behind a Cloudflare challenge. Scored absent (0 of 25). No llms.txt on youcanbook.me, the help centre or the Stoplight host (0). Descriptions, typed inputs and required fields unread (0 of 20, 0 of 15). The one response we saw is a JSON envelope with code, errors, httpCode, message and status, and the help centre gives a worked webhook payload (4 of 15). A /v1 path and x-api-version: 1.18 and x-api-revision headers, with a product updates page dated by month and no API changelog (6 of 15). 0 + 0 + 0 + 0 + 4 + 6 = 10.

Calendly API + MCP 85

incident.io status page with separate Calendly API and Webhooks components, plus each calendar provider (20). The page shows 100% uptime for the API and Webhooks components from August to November 2026, and its RSS feed, read on 1 November 2026, lists one completed maintenance window (6 September) and no incidents, so a clean record (30). 500 requests a minute per user on paid plans, 50 on Free, and booking capped at 10 a minute, 50 an hour and 100 a day below Enterprise (15). 429 with X-RateLimit-Limit, -Remaining and -Reset headers and exponential backoff advice, but no idempotency key or safe-retry guidance for booking writes (10). No SLA found on any plan (0). API v2 is GA (10).

YouCanBookMe API 15

Read with the hosted lines. The help page links a status page at www.youcanbookmestatus.com, but the host did not resolve from our reader with or without www on 3 November 2026, so it is scored as not established rather than as a finding about the vendor (0). No readable history (5). No rate limit with a number in the help centre articles, the pricing page or the API's own error response; the API reference could not be read (0). No 429 or retry guidance and no idempotency key found (0). No SLA, and the terms say the service is not guaranteed to be available 100 per cent of the time (0). The API reports version 1.18 in its headers and is sold on the Team plan, so generally available (10). 0 + 5 + 0 + 0 + 0 + 10 = 15.

Calendly API + MCP 61

39 MCP tools on the supported tools page on 1 November 2026 (5), with 5 back for two skill tools that load task guidance on demand and 2 for count on REST lists (12). next_page pagination and time and status filters on scheduled events (17). Error codes in the spec, and Free users get a clear 403 on booking (15). MCP tools carry readOnlyHint, destructiveHint and idempotentHint, but the REST booking call has no idempotency key (12). No official SDK, and the user URI from /users/me is needed before most calls (5).

YouCanBookMe API 13

Response sizing, field selection and pagination are in the unread reference (3 of 25, 0 of 20). The error envelope names a machine code and a message an agent can branch on (8 of 20). No idempotency key or safe-retry guidance found (0 of 20). No official SDK, and the required parameters are unread (2 of 15). 3 + 0 + 8 + 0 + 2 = 13.

Calendly API + MCP 70

OAuth 2.1 with PKCE and dynamic client registration on the MCP, and per-resource scopes such as scheduled_events:read and availability:write for new OAuth apps and new personal access tokens since March 2026. Tokens issued before scopes keep full access (28). Read scopes, mcp:scheduling:read and mcp:scheduling:write for the MCP, and destructiveHint on cancel, delete and revoke tools, but no confirmation step of its own (15). Invitee names and booking answers written by outsiders reach the model, with no injection guidance found (0). activity_log:read and audit logs on Enterprise (10). SOC 2 Type 2, ISO 27001, CSA STAR, an annual penetration test and a valid security.txt. No public bug bounty found (17).

YouCanBookMe API 24

One account-wide API key sent as the HTTP Basic password with the account ID or email, generated and deleted by the Account Owner only; no scopes, expiry or per-user keys are documented (10 of 30). No read-only mode or confirmation step found (0 of 20). The API and webhooks carry names, answers and notes written by people who book, with no injection guidance (2 of 15). No audit log or per-call visibility found (0 of 15). SOC 2 Type II and ISO/IEC 27001:2022 (certificate 20/3433, 20 February 2024) and third-party penetration tests on the security page, but no security.txt (404), bug bounty or disclosure policy (12 of 20). 10 + 0 + 2 + 0 + 12 = 24.

Calendly API + MCP 60

Latest release note on 30 October 2026 (Teams API), two days before this check (30). Four dated entries since 3 August (25 August, 22, 23 and 30 October) (20). Public release notes and a developer support route, no public issue tracker (10). No official SDKs (0). No package to assess (0).

YouCanBookMe API 28

Read as a closed service. The newest product update is dated September 2026 (registered SMS numbers), within 90 days but not 30, taking the month's first day (20 of 30). The previous entry is November 2025, so fewer than three in 90 days (0 of 20). A help centre, a community forum at forum.youcanbook.me and one-to-one support for paid users, with a product updates page that carries no API items (8 of 15). No official SDKs found (0). No package to assess (0). 20 + 0 + 8 + 0 + 0 = 28.

Calendly API + MCP 80

Closed service with customer terms and a separate developer policy (15). Privacy notice (3 July 2026) gives no retention periods, and the no-AI-training statement sits on the security page, not in the privacy notice (18). The v1 to v2 migration notice is dated 26 March 2025 and legacy token behaviour under scopes is written down (12). Sub-processor list linked from the privacy notice, which says data sits in the US or wherever providers operate. We didn't open the list (16).

YouCanBookMe API 61

Closed service with terms (18 March 2026) naming AI Software (Capacity) UK Ltd under English law, which bar data-mining and robot tools without consent and let the company end membership without notice for a breach (15 of 30). The privacy notice (16 March 2026) states retention periods (24 months for booking data by default, 7 years for support messages), AWS hosting in the United States, a DPA on request and no training of external AI models on booking data; the security page says no subprocessor list is published, and the two agree on AWS (22 of 30). No deprecation policy or dated notice, and clause 18.4 allows changes to the service without notice (3 of 20). Providers are named in the privacy notice (AWS, Stripe, Google Analytics, Mixpanel, Hotjar, HubSpot) with US hosting, but there is no list with locations per processor (12 of 20). 15 + 22 + 3 + 12 = 52.