# 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. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/acuity-scheduling-vs-cal-com
- Markdown: https://www.anchorterminal.com/compare/acuity-scheduling-vs-cal-com.md (~2,250 tokens)
- Slim: https://www.anchorterminal.com/compare/acuity-scheduling-vs-cal-com.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/acuity-scheduling-vs-cal-com.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: 2026-10-08

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.

- Acuity Scheduling API: grade E, 42.4/100, rank #678 of 722. Markdown https://www.anchorterminal.com/tools/acuity-scheduling.md · JSON https://www.anchorterminal.com/api/v1/tools/acuity-scheduling.json
- Cal.com API v2 + MCP: grade C, 57.2/100, rank #480 of 722. Markdown https://www.anchorterminal.com/tools/cal-com.md · JSON https://www.anchorterminal.com/api/v1/tools/cal-com.json

## Which one, for what

### Acuity Scheduling API (E)

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.

Watch for: The pricing page lists custom API access on Premium only, $61 a month or $49 billed yearly

### Cal.com API v2 + MCP (C)

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 | Acuity Scheduling API | Cal.com API v2 + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 58 | 60 | Cal.com API v2 + MCP +2 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 56 | 76 | Cal.com API v2 + MCP +20 |
| Agent ergonomics | 13% (16.2 this run) | 44 | 50 | Cal.com API v2 + MCP +6 |
| Security & auth | 14% (17.5 this run) | 27 | 56 | Cal.com API v2 + MCP +29 |
| Payments & pricing | 10% (12.5 this run) | 30 | 30 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 15 | 50 | Cal.com API v2 + MCP +35 |
| Transparency & trust | 7% (8.8 this run) | 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

1. Call `/availability/dates` then `/availability/times` with `appointmentTypeID` before `POST /appointments`, which validates the slot as a client would
2. Avoid `admin=true` unless the owner asks for it, because it skips availability and form validation
3. Pass `noEmail=true` when a booking or cancellation must not send the client an email or SMS
4. Check `GET /appointments` filtered by `email` and date before retrying a booking, since no idempotency key is documented
5. 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

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

## 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.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/acuity-scheduling-vs-cal-com.json, and with the fewest tokens: https://www.anchorterminal.com/compare/acuity-scheduling-vs-cal-com.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "acuity-scheduling", "b": "cal-com"}`. From a terminal: `anchor compare acuity-scheduling cal-com`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/acuity-scheduling.json and https://www.anchorterminal.com/api/v1/tools/cal-com.json

## Other comparisons with Acuity Scheduling API or Cal.com API v2 + MCP

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