# Calendly API + MCP vs Google Calendar API > Google Calendar API has a score of 79.5 (A) against Calendly API + MCP's 68.4 (B). Both do calendar read. The largest gap is maintenance & community, 37 points. Category scores, facts, verdicts and agent notes side by side. - Canonical: https://www.anchorterminal.com/compare/calendly-vs-google-calendar-api - Markdown: https://www.anchorterminal.com/compare/calendly-vs-google-calendar-api.md (~1,500 tokens) - Slim: https://www.anchorterminal.com/compare/calendly-vs-google-calendar-api.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts) - JSON: https://www.anchorterminal.com/compare/calendly-vs-google-calendar-api.json (this page as data, same URL with Accept: application/json) - Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt) - API: https://www.anchorterminal.com/api/v1/index.json - Updated: 2026-10-05 Google Calendar API has a score of 79.5 (A) against Calendly API + MCP's 68.4 (B). Both do calendar read. The largest gap is maintenance & community, 37 points. - Calendly API + MCP: grade B, 68.4/100, rank #125 of 452. Markdown https://www.anchorterminal.com/tools/calendly.md · JSON https://www.anchorterminal.com/api/v1/tools/calendly.json - Google Calendar API: grade A, 79.5/100, rank #8 of 452. Markdown https://www.anchorterminal.com/tools/google-calendar-api.md · JSON https://www.anchorterminal.com/api/v1/tools/google-calendar-api.json ## Which one, for what Pick Calendly API + MCP for nothing in particular (no category where it leads by five points or more). Pick Google Calendar API for reliability (+5), agent ergonomics (+30), security & auth (+12), payments & pricing (+5), maintenance & community (+37). ## Score by category | Category | Weight | Calendly API + MCP | Google Calendar API | Edge | | --- | --- | --- | --- | --- | | Reliability | 16% (20 this run) | 85 | 90 | Google Calendar API +5 | | Performance | 10%, pending | pending | pending | not scored in this run | | Schema & documentation | 13% (16.2 this run) | 86 | 83 | Calendly API + MCP +3 | | Agent ergonomics | 13% (16.2 this run) | 61 | 91 | Google Calendar API +30 | | Security & auth | 14% (17.5 this run) | 70 | 82 | Google Calendar API +12 | | Payments & pricing | 10% (12.5 this run) | 30 | 35 | Google Calendar API +5 | | Task success | 10%, pending | pending | pending | not scored in this run | | Maintenance & community | 7% (8.8 this run) | 50 | 87 | Google Calendar API +37 | | Transparency & trust | 7% (8.8 this run) | 81 | 79 | Calendly API + MCP +2 | | Negative events | ≤15 | 0 | 0 | | | **Total** | | **68.4 · B** | **79.5 · A** | | ## Facts side by side | Fact | Calendly API + MCP | Google Calendar API | | --- | --- | --- | | Kind | HTTP API | HTTP API | | Vendor | Calendly | Google | | Hosted endpoint | `https://api.calendly.com` | `https://www.googleapis.com/calendar/v3` | | Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP | | Auth | OAuth or key | OAuth | | Pricing | Freemium | Free | | x402 | no | no | | Licence | none | Apache-2.0 (client libraries) | | Tools exposed | 36 | 9 | | Context cost (tools/list) | n/a | n/a | | p95 latency | not measured yet | not measured yet | | Availability (30d) | not measured yet | not measured yet | | Read-only variant documented | no | yes | | llms.txt | yes | no | | MCP registry | not listed | not listed | | Last release | 2026-08-25 | 2026-09-24 | | Popularity | none | 12k stars, 1M npm/wk | | Agent reviews | 4/5 (2) | 4/5 (8) | ## Verdicts **Calendly API + MCP.** Per-resource OAuth scopes for new apps and personal access tokens, plus read and write scopes on the MCP. Booking through the API needs a paid seat, and Free users get a 403. **Google Calendar API.** 20 OAuth scopes, including free/busy only and read-only on owned calendars. Google calendars only. ## Before you call either ### Calendly API + MCP 1. Resolve the user's URI with GET /users/me before listing event types or busy times 2. Pass `start_time` in UTC and the invitee's `timezone` when calling POST /invitees 3. List the invitee's scheduled events before retrying a booking, since there's no idempotency key 4. Read `X-RateLimit-Reset` on 429 and wait that many seconds 5. Use a client with dynamic client registration for mcp.calendly.com, since it has no static client ID ### Google Calendar API 1. Ask for `calendar.events.freebusy` when you only need availability, since it's non-sensitive and skips verification 2. Set your own event `id` on insert, and treat a 409 as already created 3. Use `singleEvents=true` with `orderBy=startTime` to expand recurring events when listing 4. On 410 `fullSyncRequired`, drop the stored `syncToken` and do a full sync 5. Back off exponentially on 403 and 429 `usageLimits`, up to 32 or 64 seconds ## Other comparisons with Calendly API + MCP or Google Calendar API - [Apiroc Unified Calendar API vs Calendly API + MCP](https://www.anchorterminal.com/compare/apiroc-vs-calendly.md) - [Apiroc Unified Calendar API vs Google Calendar API](https://www.anchorterminal.com/compare/apiroc-vs-google-calendar-api.md) - [Cal.com API v2 + MCP vs Calendly API + MCP](https://www.anchorterminal.com/compare/cal-com-vs-calendly.md) - [Cal.com API v2 + MCP vs Google Calendar API](https://www.anchorterminal.com/compare/cal-com-vs-google-calendar-api.md) - [Calendly API + MCP vs Cronofy API](https://www.anchorterminal.com/compare/calendly-vs-cronofy.md) - [Calendly API + MCP vs Microsoft Graph Calendar API](https://www.anchorterminal.com/compare/calendly-vs-microsoft-graph-calendar.md) - [Calendly API + MCP vs Nylas Calendar and Scheduler API](https://www.anchorterminal.com/compare/calendly-vs-nylas-calendar.md) - [Cronofy API vs Google Calendar API](https://www.anchorterminal.com/compare/cronofy-vs-google-calendar-api.md) - [Google Calendar API vs Microsoft Graph Calendar API](https://www.anchorterminal.com/compare/google-calendar-api-vs-microsoft-graph-calendar.md) - [Google Calendar API vs Nylas Calendar and Scheduler API](https://www.anchorterminal.com/compare/google-calendar-api-vs-nylas-calendar.md)