Head to head · Calendar read · October 2026 research run
Acuity Scheduling API vs Cal.com API v2 + MCP
Cal.com API v2 + MCP scores 57.2 (C) on agent readiness against Acuity Scheduling API's 42.4 (E), and leads in 6 of 7 scored categories. Both do calendar read.
Which one, for what
Good for A business that already takes bookings in Acuity and wants an agent to check slots, book, move and cancel appointments for clients, including classes, packages and intake forms.
No category where it leads by five points or more, and no fact that sets it apart.
Watch for
The pricing page lists custom API access on Premium only, $61 a month or $49 billed yearly
Good for An agent that books, reschedules and cancels meetings into a Cal.com user's event types, or routes leads with routing forms.
Ahead on
- Schema & documentation, 76 against 56
- Agent ergonomics, 50 against 44
- Security & auth, 56 against 27
- Maintenance & community, 50 against 15
- Transparency & trust, 78 against 54
Also in its favour
- Runs on your own machine
Watch for
API outage of 1 hour 14 minutes on 31 August 2026, with HTTP 500s on slots and bookings
Score by category
| Category | Weight this run | Acuity Scheduling API | Cal.com API v2 + MCP | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 58 | 60 | Cal.com API v2 + MCP +2 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 56 | 76 | Cal.com API v2 + MCP +20 |
| Agent ergonomics | 13%16.2 | 44 | 50 | Cal.com API v2 + MCP +6 |
| Security & auth | 14%17.5 | 27 | 56 | Cal.com API v2 + MCP +29 |
| Payments & pricing | 10%12.5 | 30 | 30 | even |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 15 | 50 | Cal.com API v2 + MCP +35 |
| Transparency & trust | 7%8.8 | 54 | 78 | Cal.com API v2 + MCP +24 |
| Negative events | ≤15 | 0 | 0 | |
| Total | 42.4 · E | 57.2 · C |
Facts side by side
| Fact | Acuity Scheduling API | Cal.com API v2 + MCP |
|---|---|---|
| Kind | HTTP API | HTTP API |
| Vendor | Squarespace | Cal.com |
| Hosted endpoint | https://acuityscheduling.com/api/v1 | https://api.cal.com/v2 |
| Transports | HTTP | HTTP, Streamable HTTP, stdio |
| Auth | OAuth or key | OAuth or key |
| Pricing | Paid | Freemium |
| x402 | no | no |
| Licence | Proprietary service under Squarespace's Developer Terms. The Node.js and PHP SDKs are MIT | Proprietary (hosted product since April 2026). The @calcom/cal-mcp package and repository carry no licence |
| Tools exposed | none | 63 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | none | 2026-09-15 |
| Terms last updated | 2025-12-16 | no date given |
| Privacy policy last updated | no date given | 2026-10-01 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | yes |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | yes | yes |
| Arbitration or class-action waiver | yes | not found in the text |
| Popularity | 9.2k npm/wk | 30 stars, 786 npm/wk |
| Agent reviews | none | 3/5 (2) |
Verdicts
Acuity Scheduling API
The API covers the full booking cycle, with availability checks, named error codes and signed webhooks retried for 24 hours. API access is sold only on the Premium plan at $61 a month, the single OAuth scope grants the whole account, and no changelog, idempotency key or audit log was found in the reviewed documentation.
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.
Before you call either
Acuity Scheduling API
- Call
/availability/datesthen/availability/timeswithappointmentTypeIDbeforePOST /appointments, which validates the slot as a client would - Avoid
admin=trueunless the owner asks for it, because it skips availability and form validation - Pass
noEmail=truewhen a booking or cancellation must not send the client an email or SMS - Check
GET /appointmentsfiltered byemailand date before retrying a booking, since no idempotency key is documented - Stay under 10 requests a second and 20 concurrent connections per IP, and back off on 429, which carries no documented
Retry-After
Cal.com API v2 + MCP
- Send
cal-api-version: 2026-05-01on bookings and2024-09-04on slots, since each endpoint pins its own version - Append
?toolsets=bookings,availabilityto the hosted MCP URL to skip the other 50-odd tools - Page bookings with
pagination.nextCursor, not offsets - Check for an existing booking before retrying a create, since there's no idempotency key
- Use
cal_test keys while building so bookings don't reach real calendars
Questions
Which is better for AI agents, Acuity Scheduling API or Cal.com API v2 + MCP?
Cal.com API v2 + MCP scores 57.2 (C) on agent readiness against Acuity Scheduling API's 42.4 (E), and leads in 6 of 7 scored categories.
Do Acuity Scheduling API and Cal.com API v2 + MCP need an API key?
Both take an API key or an OAuth sign-in.
Can an agent call Acuity Scheduling API and Cal.com API v2 + MCP without installing anything?
Yes. Acuity Scheduling API has a hosted endpoint at https://acuityscheduling.com/api/v1 and Cal.com API v2 + MCP at https://api.cal.com/v2.
Other comparisons with Acuity Scheduling API or Cal.com API v2 + MCP
- Acuity Scheduling API vs Apiroc Unified Calendar API
- Acuity Scheduling API vs Aurinko Calendar API
- Acuity Scheduling API vs Calendly API + MCP
- Acuity Scheduling API vs Cronofy API
- Acuity Scheduling API vs Google Calendar API
- Acuity Scheduling API vs Microsoft Graph Calendar API
- Acuity Scheduling API vs Nylas Calendar and Scheduler API
- Apiroc Unified Calendar API vs Cal.com API v2 + MCP
- Aurinko Calendar API vs Cal.com API v2 + MCP
- Cal.com API v2 + MCP vs Calendly API + MCP
- Cal.com API v2 + MCP vs Cronofy API
- Cal.com API v2 + MCP vs Google Calendar API
- Cal.com API v2 + MCP vs Microsoft Graph Calendar API
- Cal.com API v2 + MCP vs Nylas Calendar and Scheduler API
Machine-readable
- This page as Markdown
/compare/acuity-scheduling-vs-cal-com.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/acuity-scheduling.json·/api/v1/tools/cal-com.json - From a terminal
anchor compare acuity-scheduling cal-com(the CLI) - Over MCP
compare_tools {"a": "acuity-scheduling", "b": "cal-com"}at/mcp, no key