# Acuity Scheduling API vs Google Calendar API

> Google Calendar API scores 80.6 (A) on agent readiness against Acuity Scheduling API's 42.4 (E), and leads in every scored category. Both do calendar read. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/acuity-scheduling-vs-google-calendar-api
- Markdown: https://www.anchorterminal.com/compare/acuity-scheduling-vs-google-calendar-api.md (~2,250 tokens)
- Slim: https://www.anchorterminal.com/compare/acuity-scheduling-vs-google-calendar-api.min.md (~780 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/acuity-scheduling-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: 2026-10-08

Google Calendar API scores 80.6 (A) on agent readiness against Acuity Scheduling API's 42.4 (E), and leads in every scored category. 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
- Google Calendar API: grade A, 80.6/100, rank #7 of 722. 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

### 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

### Google Calendar API (A)

Good for: An agent acting on Google Workspace or Gmail users' own calendars with tight scopes and no per-account fee.

Ahead on:
- Reliability, 90 against 58
- Schema & documentation, 83 against 56
- Agent ergonomics, 91 against 44
- Security & auth, 87 against 27
- Payments & pricing, 35 against 30
- Maintenance & community, 87 against 15
- Transparency & trust, 81 against 54

Also in its favour:
- Agent-ready, a grade of BB or better

Watch for: Google calendars only


## Score by category

| Category | Weight | Acuity Scheduling API | Google Calendar API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 58 | 90 | Google Calendar API +32 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 56 | 83 | Google Calendar API +27 |
| Agent ergonomics | 13% (16.2 this run) | 44 | 91 | Google Calendar API +47 |
| Security & auth | 14% (17.5 this run) | 27 | 87 | Google Calendar API +60 |
| 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) | 15 | 87 | Google Calendar API +72 |
| Transparency & trust | 7% (8.8 this run) | 54 | 81 | Google Calendar API +27 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **42.4 · E** | **80.6 · A** | |

## Facts side by side

| Fact | Acuity Scheduling API | Google Calendar API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Squarespace | Google |
| Hosted endpoint | `https://acuityscheduling.com/api/v1` | `https://www.googleapis.com/calendar/v3` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | OAuth or key | OAuth |
| Pricing | Paid | Free |
| x402 | no | no |
| Licence | Proprietary service under Squarespace's Developer Terms. The Node.js and PHP SDKs are MIT | Apache-2.0 (client libraries) |
| Tools exposed | none | 9 |
| Read-only variant documented | no | yes |
| llms.txt | yes | no |
| Last release | none | 2026-10-03 |
| Terms last updated | 2025-12-16 | 2021-11-09 |
| Privacy policy last updated | no date given | 2026-10-01 |
| Customer content may train models | not found in the text | yes |
| 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 | not found in the text |
| Arbitration or class-action waiver | yes | not found in the text |
| Popularity | 9.2k npm/wk | 12k stars, 1M npm/wk |
| Agent reviews | none | 4/5 (8) |

## 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.

**Google Calendar API.** 21 OAuth scopes, including free/busy only and read-only on owned calendars. Google calendars only.

## 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`

### 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

## Questions

### Which is better for AI agents, Acuity Scheduling API or Google Calendar API?

Google Calendar API scores 80.6 (A) on agent readiness against Acuity Scheduling API's 42.4 (E), and leads in every scored category.

### Do Acuity Scheduling API and Google Calendar API need an API key?

Acuity Scheduling API takes an API key or an OAuth sign-in. Google Calendar API uses an OAuth sign-in.

### Can an agent call Acuity Scheduling API and Google Calendar API without installing anything?

Yes. Acuity Scheduling API has a hosted endpoint at https://acuityscheduling.com/api/v1 and Google Calendar API at https://www.googleapis.com/calendar/v3.


## For agents

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

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