Calendly API + MCP vs SavvyCal API + MCP

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).

SavvyCal API + MCP 50

OAuth 2 authorisation code apps with 2-hour access tokens and refresh tokens, and personal access tokens, both in the Authorization header only. The spec declares no scopes for either, and PAT expiry and revocation are not described. The MCP server uses OAuth 2.1 with PKCE S256, dynamic client registration, mcp:read and mcp:write scopes and a revocation endpoint (22 of 30). mcp:read gives a read-only MCP grant, and the vendor says the assistant asks before booking, cancelling, deleting or inviting. REST tokens have no read-only form (14 of 20). Invitee names, answers and metadata written by outsiders come back through events and webhooks with no injection guidance; the AI page says the assistant sees calendar conflicts but not event names (2 of 15). Webhook request logs and a Connected Apps list with revoke, but no per-call audit log for the operator (4 of 15). Valid security.txt to 2 May 2027, a security page and an SSDLC page, but no SOC 2 or ISO 27001 (the page says not yet) and no bug bounty (8 of 20). 22 + 14 + 2 + 4 + 8 = 50.

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).

SavvyCal API + MCP 40

Read as a closed service. The newest dated change is the MCP integration of 27 October 2026 on the updates board (30). It is the only dated entry since 7 July, so fewer than three in 90 days (0 of 20). A public updates board, a feature request board and a support address with a stated 24-hour reply within US Central business hours (10 of 15). No official SDKs (0). No package to assess (0). 30 + 0 + 10 + 0 + 0 = 40.

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).

SavvyCal API + MCP 70

Read with the hosted lines. Instatus page at savvycal.instatus.com with App, Microsoft 365, Google Calendar and Integrations components and a month-by-month history (20). No notices from June to November 2026 and 100 per cent App uptime each month, a clean record (30). The only limit with a number is in the OpenAPI spec, 10 event creations a minute per link, failed ones included; nothing covers the rest of the API (7 of 15). That 429 is declared with no Retry-After, backoff guidance or idempotency key, and webhooks are the only place retries are described (3 of 15). No SLA; the terms give the service as is (0). The v1 API is generally available and the MCP server, announced 27 October 2026, is not marked beta (10). 20 + 30 + 7 + 3 + 0 + 10 = 70.

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).

SavvyCal API + MCP 74

OpenAPI 3.0.0 at api.savvycal.com/v1/spec covers all 22 operations with 56 schemas; the MCP tools' schemas could not be read without signing in (23 of 25). llms.txt and a Markdown twin of every docs page (10). Only 8 of the 22 operations carry a description, and those state constraints (events must match an open slot, an invalid filter resets every filter) rather than when to choose another endpoint (10 of 20). Required flags on 14 of 43 parameters, 34 enum properties across the schemas, limit bounded 1 to 100, until at most 31 days after from (12 of 15). Example values on parameters and a documented error shape keyed by field, with 400, 401, 404, 422 and 429 declared per operation, but no full response examples (10 of 15). A /v1 path and a promise that changes are additive, with dated product updates on the feedback board but no API changelog (9 of 15). 23 + 10 + 10 + 12 + 10 + 9 = 74.

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).

SavvyCal API + MCP 53

List responses are sized by limit (default 20, at most 100) with no field selection. The MCP server lists 63 tools with no documented toolset or read-only list, though a client can ask for the mcp:read scope alone (10 of 25). Cursor pagination with after, before and limit, and date and status filters on events (17 of 20). Errors name the field, the failed validation and a limit count, which an agent can act on, but a 429 carries no wait time (14 of 20). No idempotency key on booking or link creation, and the MCP annotations could not be read; the docs say the assistant confirms before cancelling, deleting or inviting (6 of 20). Creating an event needs five fields, and there is no official SDK in any language (6 of 15). 10 + 17 + 14 + 6 + 6 = 53.

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).

SavvyCal API + MCP 73

Closed service with terms that name SavvyCal, Inc. under Minnesota law and forbid automated access to the site, with the API left to the developer docs (15 of 30). The privacy policy (17 October 2026), DPA (16 January 2023) and processor list (24 October 2026) agree on US hosting, Stripe and return or destruction on termination, but no retention period is stated beyond account lifetime (22 of 30). The developer overview promises additive changes; there is no deprecation policy or dated notice, and the terms allow any feature to change without notice (5 of 20). A processor list with purposes, hosting on Fly.io in Virginia and Crunchy Bridge on AWS us-east, but no locations per processor (15 of 20). 15 + 22 + 5 + 15 = 57.