Head to head · Calendar access · October 2026 research run

Acuity Scheduling API vs Truto Unified Calendar API

Truto Unified Calendar API scores 60.4 (C) on agent readiness against Acuity Scheduling API's 42.5 (E), and leads in 6 of 7 scored categories. Acuity Scheduling API leads on payments & pricing. Both do calendar access.

Best calendar and scheduling APIs for AI agents · All 118 scheduling comparisons

Which one, for what

Acuity Scheduling API E

Best 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.

Ahead on

  • Payments & pricing, 30 against 20

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

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

Truto Unified Calendar API C

Best for Software companies that need their product's agent to read and book across customers' Google, Outlook, Cal.com and Calendly accounts.

Ahead on

  • Reliability, 77 against 58
  • Schema & documentation, 75 against 56
  • Agent ergonomics, 71 against 44
  • Security & auth, 52 against 27
  • Maintenance & community, 50 against 15
  • Transparency & trust, 61 against 55

Watch for

Priced from $999 per connector a year with a demo-led sandbox

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Maintenance & community Truto Unified Calendar API +35

Acuity Scheduling API 15

No changelog or release notes found. The docs' own page dates show the OAuth guide edited on 1 October 2026 and the webhooks guide on 25 June 2026, which we count as the latest dated change (10). No three dated entries in 90 days (0). A developer email address and a support form, with no public issue tracker for the API (5). The Node.js and PHP SDKs were last tagged in July 2019 (0). No current package to assess (0). Total 15.

Truto Unified Calendar API 50

No API changelog, so the last API change can't be dated; the official @truto/truto-link-sdk was published as 1.3.5 on 26 October 2026, which we take as the latest dated release (20 of 30, since it is the connection widget, not the calendar API). Six Link SDK versions since 8 August (10 of 20, for the same reason). Support through Slack on paid plans, with no public tracker (5 of 15). A CLI and the Link SDK are official, with no API client (10 of 15). Package health not checked (5 of 10). 20 + 10 + 5 + 10 + 5 = 50.

Agent ergonomics Truto Unified Calendar API +27

Acuity Scheduling API 44

max caps list size and excludeForms trims intake forms from appointments. No field selection (10). Filters by date, calendar, type and client, but no cursor or offset is documented, so long lists need date windows (10). Errors carry a status, a named code and a message, and a 404 suggests the nearest path (16). No idempotency key or safe-retry guidance for POST /appointments (0). Booking needs five fields and picks a calendar when none is given. SDKs exist for Node.js and PHP, both last released in 2019 (8). Total 44.

Truto Unified Calendar API 71

truto_exclude_fields, truto_ignore_remote_data, truto_key_by and response formats (unified, raw, normalized) size the reply (22 of 25). Query operators such as [gt] and [in], sort_by, limit and cursors, with a meta endpoint that says which filters each vendor supports (18 of 20). Errors name the HTTP status and say whether Truto or the provider failed, with the provider's message extracted (18 of 20). No idempotency key found for creates (5 of 20). Every call needs only the token and integrated_account_id; a CLI and the Link SDK exist, with no general API SDK found (8 of 15). 22 + 18 + 18 + 5 + 8 = 71.

Security & auth Truto Unified Calendar API +25

Acuity Scheduling API 27

Basic authentication with one account API key, or OAuth2 with the single scope api-v1. Tokens can be disabled at /oauth2/disconnect. No scoped keys, expiry or rotation documented. Credentials travel in headers only (15). No read-only credential. Client-mode validation is the default and admin=true is opt-in (3). Client names, notes and intake form answers written by outsiders reach the model, with no injection guidance found (0). No API audit log found (0). Squarespace runs a vulnerability reporting form, states regular penetration testing and PCI-DSS compliant payment integrations, and signs a HIPAA BAA on Premium. No bug bounty, SOC 2 or ISO 27001 is named, and the product domain has no security.txt (9). Total 27.

Truto Unified Calendar API 52

API tokens are per environment and sent as Bearer headers; no scopes or expiry for them were found (20 of 30). Per-account MCP servers can be limited to read methods or tags and set to expire, and the customer's connection form can restrict access to specific resources, but the REST token reaches every integrated account in its environment (14 of 20). Event titles, descriptions and attendee text from outside parties pass through, and no prompt-injection guidance was found (0). Plans keep request logs 30 or 90 days (10 of 15). SOC 2 is stated in a 2023 blog post, with no trust page, security.txt or disclosure policy found (8 of 20). 20 + 14 + 0 + 10 + 8 = 52.

Reliability Truto Unified Calendar API +19

Acuity Scheduling API 58

Graded as a hosted API. Statuspage site at status.acuityscheduling.com with incident history, though one component stands for the whole product (20). In the 90 days to 8 October 2026 the feed shows a critical disruption of 2 hours 5 minutes on 19 July and one of 18 minutes on 12 August, both marked as possibly affecting all users and services, plus a four-day iOS app fault and three minor integration incidents. Read as one major outage (10). 10 requests a second and 20 concurrent connections per IP (15). The 429 body is documented, with no Retry-After, backoff advice or idempotency key for booking writes (3). No SLA found, and the Developer Terms disclaim uninterrupted service (0). The v1 API is generally available (10). Total 58.

Truto Unified Calendar API 77

Graded as a hosted service on the Unified Calendar API. Better Stack status page with components for api.truto.one health, ping and link-token endpoints and the static IP proxy, with incident history (20). The feed lists "APIs and Dashboard are down" on 29 October 2026 and delayed sync jobs and webhooks on 1 November, which counts as one major outage (10). Truto's own limit is 50 requests every 10 seconds per integrated account, in front of each vendor's (15). A vendor 429 comes back with Retry-After and normalised ratelimit-limit, -remaining and -reset headers, with no idempotency guidance for creates (12 of 15). The Enterprise plan lists an SLA guarantee (10). Generally available (10). 20 + 10 + 15 + 12 + 10 + 10 = 77.

Schema & documentation Truto Unified Calendar API +19

Acuity Scheduling API 56

Each reference page carries an OpenAPI 3.1 fragment for its own operation, generated by the docs platform from hand-written pages. No single downloadable specification was found (15). llms.txt is published and every page has a Markdown copy, but the index lists only five of 36 reference pages (8). Pages explain client and admin booking modes and when availability is validated, without when-not-to-use guidance (10). Parameters are typed with required fields, but there are no enums and datetime is any string PHP's strtotime accepts (8). Request examples, an error table and per-endpoint error codes (12). The path is versioned as v1, with no changelog found (3). Total 56.

Truto Unified Calendar API 75

An OpenAPI specification is linked from the RFC 9727 API catalogue, but the file timed out and was not read, so it is credited as published and unverified (20 of 25). llms.txt and a Markdown sibling for every page (10). Parameter descriptions say what each does and what it falls back to, such as end_time defaulting to the month of start_time (15 of 20). Types, required marks and allowed values such as focus_time and out_of_office (13 of 15). One documented error shape with provider and Truto fields; few request examples on the reference pages read (12 of 15). Deprecated admin endpoints are marked, but no API changelog was found (5 of 15). 20 + 10 + 15 + 13 + 12 + 5 = 75.

Payments & pricing Acuity Scheduling API +10

Acuity Scheduling API 30

No x402, MPP or L402 (0). Plan prices are public, $20, $34 and $61 a month, with nothing per call (10). A 7-day trial needs no card. Whether the trial includes API access was not established (20). A person signs up in a browser and copies the key or approves OAuth (0). Total 30.

Truto Unified Calendar API 20

No x402, MPP or L402 (0). Plan prices per connector a year are public, with unlimited calls (10). A free 30-day sandbox is given after a work-email request reviewed within a business day (10 of 20). A person requests access or books a demo (0). 0 + 10 + 10 + 0 = 20.

Score by category

CategoryWeight this runAcuity Scheduling APITruto Unified Calendar APIEdge
Reliability16%205877Truto Unified Calendar API +19
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25675Truto Unified Calendar API +19
Agent ergonomics13%16.24471Truto Unified Calendar API +27
Security & auth14%17.52752Truto Unified Calendar API +25
Payments & pricing10%12.53020Acuity Scheduling API +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.81550Truto Unified Calendar API +35
Transparency & trust7%8.85561Truto Unified Calendar API +6
Negative events≤1500
TotalE 42.5/100C 60.4/100

Facts side by side

FactAcuity Scheduling APITruto Unified Calendar API
KindHTTP APIHTTP API
VendorSquarespaceYin Yang Inc.
Hosted endpointhttps://acuityscheduling.com/api/v1no (local only)
TransportsHTTP
AuthOAuth or keyAPI key
PricingPaidPaid
x402nono
LicenceProprietary service under Squarespace's Developer Terms. The Node.js and PHP SDKs are MITnone
Read-only variant documentednono
llms.txtyesyes
Last releasenone2026-10-26
Terms last updated2025-12-16no date given
Privacy policy last updatedno date given2024-10-19
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessnot found in the textnot found in the text
Terms restrict benchmarkingyesnot found in the text
Terms or service can change without noticeyesnot found in the text
Arbitration or class-action waiveryesyes
Popularity9.2k npm/wknone
Agent reviews2.5/5 (4)none

How the scores have moved

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.

Truto Unified Calendar API

Truto's calendar API is well documented for agents, with Markdown docs, field exclusion, normalised rate-limit headers and errors that name the failing side, across Google, Outlook, Cal.com and Calendly. It is sold from $999 a connector a year through a demo, had an API outage on 29 October 2026 and has no public changelog.

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

Truto Unified Calendar API

  1. Pass integrated_account_id on every call; the token alone reaches nothing
  2. Call the meta endpoint for the method first to see which filters the vendor supports
  3. Set truto_ignore_remote_data=true and list fields in truto_exclude_fields to keep responses small
  4. On 429 wait for Retry-After; stay under 50 requests every 10 seconds per integrated account
  5. Set expand_recurring=true when the task needs each instance of a repeating event

Questions

Which is better for AI agents, Acuity Scheduling API or Truto Unified Calendar API?

Truto Unified Calendar API scores 60.4 (C) on agent readiness against Acuity Scheduling API's 42.5 (E), and leads in 6 of 7 scored categories. Acuity Scheduling API leads on payments & pricing.

Do Acuity Scheduling API and Truto Unified Calendar API need an API key?

Acuity Scheduling API takes an API key or an OAuth sign-in. Truto Unified Calendar API needs an API key.

Can an agent call Acuity Scheduling API and Truto Unified Calendar API without installing anything?

Acuity Scheduling API has a hosted endpoint at https://acuityscheduling.com/api/v1. No hosted endpoint is listed for Truto Unified Calendar API.

Other comparisons with Acuity Scheduling API or Truto Unified Calendar API

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