Skip to content
verify mcp Beta VerifyMCP is currently in beta. If you notice any issues, get in touch and we’ll put it right.

io.usefulapi/acuity-scheduling

REMOTE · ACUITY-SCHEDULING.USEFULAPI.IO · SCANNED SEP 20

Read appointments, types, calendars and availability; create, cancel or reschedule bookings.

−13 this week 74 Trust /100
Trust breakdown (7 categories)

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →

Endpoint Security46
  • The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
  • Authorisation not fully verified: this server exposes a tool marked destructive (acuity_create_appointment) and its handshake is open, but we could not confirm whether a tool call is gated, so we do not assert it is callable unauthenticated. View diagnostics → Unverified
  • HTTPS enforcement could not be verified: the plaintext port answered with HTTP 401, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
  • HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
  • DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
Schema Quality & AI Usability84
  • AI-judged instruction clarity (excellent).Pass
  • Tool/resource definitions use about 1627 tokens (~90/item across 18 items; 18 tools + 0 resources), lean.Pass
  • Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management97
  • Stability check failed: schema churn in the 30 days we've observed: 0 tool removals, 0 breaking changes, 1 auth/transport breaks, 0 additions. See how to fix → Fail
Tool Coverage100
  • 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
  • 100% of tool parameters carry a description.Pass
Tool Safety100
  • No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
  • We read all 18 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
  • An AI judge read all 18 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities60
  • Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28. See how to fix → Fail
Install

How do I install the io.usefulapi/acuity-scheduling MCP server?

io.usefulapi/acuity-scheduling is a hosted endpoint at https://acuity-scheduling.usefulapi.io/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

remote · acuity-scheduling.usefulapi.io

# add to Claude Code
claude mcp add --transport http io-usefulapi-acuity-scheduling 'https://acuity-scheduling.usefulapi.io/mcp'
// .cursor/mcp.json
{
  "mcpServers": {
    "io-usefulapi-acuity-scheduling": {
      "url": "https://acuity-scheduling.usefulapi.io/mcp"
    }
  }
}
// .vscode/mcp.json
{
  "servers": {
    "io-usefulapi-acuity-scheduling": {
      "type": "http",
      "url": "https://acuity-scheduling.usefulapi.io/mcp"
    }
  }
}
# ~/.codex/config.toml
[mcp_servers.io-usefulapi-acuity-scheduling]
url = "https://acuity-scheduling.usefulapi.io/mcp"
// opencode.json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "io-usefulapi-acuity-scheduling": {
      "type": "remote",
      "url": "https://acuity-scheduling.usefulapi.io/mcp",
      "enabled": true
    }
  }
}
# add to OpenClaw
openclaw mcp add io-usefulapi-acuity-scheduling --url 'https://acuity-scheduling.usefulapi.io/mcp' --transport streamable-http
# ~/.hermes/config.yaml
mcp_servers:
  io-usefulapi-acuity-scheduling:
    url: "https://acuity-scheduling.usefulapi.io/mcp"
// ~/.netclaw/config/netclaw.json
{
  "McpServers": {
    "io-usefulapi-acuity-scheduling": {
      "Transport": "http",
      "Url": "https://acuity-scheduling.usefulapi.io/mcp"
    }
  }
}
# add to Vellum
assistant mcp add io-usefulapi-acuity-scheduling -t streamable-http -u 'https://acuity-scheduling.usefulapi.io/mcp'
// mcp.json
{
  "mcpServers": {
    "io-usefulapi-acuity-scheduling": {
      "type": "http",
      "url": "https://acuity-scheduling.usefulapi.io/mcp"
    }
  }
}

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

Changelog

Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.

  • 20 Sept 26 −13
    • Authorization: pass → unverified security
    • Stability: pass → fail security
  • 17 Sept 26 +59
    • Authorization: unverified → pass security
    • Injection markers: unverified → pass security
    • Stability: unverified → pass security
    • MCP protocol: unverified → fail functional
    • Endpoint reachability: behind authorisation → reachable functional
    • Tool coverage: unverified → 100 functional
  • 16 Sept 26 −59
    • Endpoint reachability: reachable → behind authorisation security
    • Authorization: pass → unverified security
    • Stability: pass → unverified security
    • Tool safety: pass → unverified security
    • Capabilities: fail → unverified functional
    • Tool coverage: 100 → unverified functional
    • First check of Schema quality: unverified functional
  • 26 Aug 26 +1
    • We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
  • 25 Aug 26 0
    • Stability: 0.97 → pass security
  • 24 Aug 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.

  • 11 Aug 26 0
    • We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
  • 2 Aug 26 0
    • Endpoint reachability: reachable → not serving MCP security
    • Authorization: pass → unverified security
    • Stability: 0.20 → unverified security
    • Capabilities: fail → unverified functional
    • Tool coverage: 100 → unverified functional
    • Endpoint reachability: not serving MCP → reachable functional
    • First check of Schema quality: unverified functional
Diagnostics

Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.

Captured 20 Sept 2026 · Probed https://acuity-scheduling.usefulapi.io/mcp

TLS valid

Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .

Subject Issuer Valid from Valid until Key Signature Serial
CN=usefulapi.io CN=WE1,O=Google Trust Services,C=US 16 Sept 2026 15 Dec 2026 ECDSA 256 ECDSA-SHA256 de5b6f5929f1cc500e96fa7e5ea1fb71
SANs: usefulapi.io, acuity-scheduling.usefulapi.io, *.acuity-scheduling.usefulapi.io
CN=WE1,O=Google Trust Services,C=US (CA) CN=GTS Root R4,O=Google Trust Services LLC,C=US 13 Dec 2023 20 Feb 2029 ECDSA 256 ECDSA-SHA384 7ff31977972c224a76155d13b6d685e3
CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE 15 Nov 2023 28 Jan 2028 ECDSA 384 SHA256-RSA 7fe530bf331343bedd821610493d8a1b

Background: What to check on a remote MCP endpoint →

DNSSEC insecure

Validation of acuity-scheduling.usefulapi.io. Not signed

Zone DS Keys Algorithms Outcome
. trust_anchor 20326, 38696 8, 8 Verified
io. present 57355 8 Verified
usefulapi.io. absent Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation
Authentication No authorisation required

The endpoint answered without asking for a token. Anyone who knows the URL can reach it.

Result No authorisation required
HTTP status 200

Background: How OAuth 2.1 works in the 2026 MCP spec →

Transports 2 probes
Transport URL Outcome Status Location
streamable-http https://acuity-scheduling.usefulapi.io/mcp Verified 200
http (plaintext) http://acuity-scheduling.usefulapi.io/mcp Inconclusive 401
MCP tools · 18 exposed · ~1,627 tokens

The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →

Tool Tokens
acuity_availability_classes ~115

List group class time slots (for class-type appointment types) in a month. Acuity REST: GET /availability/classes.

NameTypeReqDescription
appointmentTypeIDintegeryesClass appointment type id (required).
includeUnavailablebooleanIf true, also include full/unavailable class times.
monthstringyesMonth to check, formatted YYYY-MM, e.g. '2026-08'.
timezonestringIANA timezone for the returned times, e.g. 'America/New_York'.

No output schema declared.

No examples provided.

acuity_availability_dates ~113

List dates in a month that have availability for an appointment type. Acuity REST: GET /availability/dates.

NameTypeReqDescription
appointmentTypeIDintegeryesAppointment type id to check availability for (required).
calendarIDintegerRestrict to a specific calendar id.
monthstringyesMonth to check, formatted YYYY-MM, e.g. '2026-08'.
timezonestringIANA timezone for the returned dates, e.g. 'America/New_York'.

No output schema declared.

No examples provided.

acuity_availability_times ~116

List available time slots on a given date for an appointment type. Acuity REST: GET /availability/times.

NameTypeReqDescription
appointmentTypeIDintegeryesAppointment type id to check availability for (required).
calendarIDintegerRestrict to a specific calendar id.
datestringyesDate to check, formatted YYYY-MM-DD, e.g. '2026-08-15'.
timezonestringIANA timezone for the returned times, e.g. 'America/New_York'.

No output schema declared.

No examples provided.

acuity_cancel_appointment ~105

CANCELS an existing appointment. This MODIFIES the calendar and, unless suppressed, may send cancellation emails. Acuity REST: PUT /appointments/{id}/cancel.

NameTypeReqDescription
adminbooleanIf true, cancel as admin (bypasses client cancellation restrictions).
cancelNotestringOptional note explaining the cancellation.
idintegeryesAppointment id to cancel (required).
noEmailbooleanIf true, suppress cancellation emails.

No output schema declared.

No examples provided.

acuity_create_appointment ~265

CREATES a new appointment (books a client into a time slot). This MODIFIES the calendar and, unless suppressed, may send confirmation emails. Acuity REST: POST /appointments.

NameTypeReqDescription
adminbooleanIf true, book as admin — bypasses availability checks and required-form enforcement. Default false.
appointmentTypeIDintegeryesAppointment type id to book (required).
calendarIDintegerCalendar id to book on (defaults to an available one).
datetimestringyesStart time in ISO 8601 with offset, e.g. '2026-08-15T14:00:00-0400' (required).
emailstringyesClient email (required).
fieldsarrayIntake form field answers, each { id, value }.
firstNamestringyesClient first name (required).
lastNamestringyesClient last name (required).
noEmailbooleanIf true, suppress client/owner confirmation emails.
notesstringNotes to attach to the appointment.
phonestringClient phone number.
timezonestringIANA timezone for the datetime, e.g. 'America/New_York'.

No output schema declared.

No examples provided.

acuity_create_client ~95

CREATES a new client record in the account's client list. This ADDS data to the account. Acuity REST: POST /clients.

NameTypeReqDescription
emailstringClient email.
firstNamestringyesClient first name (required).
lastNamestringyesClient last name (required).
notesstringNotes about the client.
phonestringClient phone number.

No output schema declared.

No examples provided.

acuity_get_appointment ~38

Get a single appointment by its id. Acuity REST: GET /appointments/{id}.

NameTypeReqDescription
idintegeryesAppointment id.

No output schema declared.

No examples provided.

acuity_get_me ~37

Get the authenticated Acuity account's profile (name, email, timezone, plan, currency). Acuity REST: GET /me.

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

acuity_list_appointment_types ~57

List the account's appointment types (services and classes), including price, duration and calendars. Acuity REST: GET /appointment-types.

NameTypeReqDescription
includeDeletedbooleanIf true, also include deleted/inactive appointment types.

No output schema declared.

No examples provided.

acuity_list_appointments ~186

List appointments scheduled on the account, with optional filters. Acuity REST: GET /appointments.

NameTypeReqDescription
appointmentTypeIDintegerFilter to a specific appointment type id.
calendarIDintegerFilter to a specific calendar id.
canceledbooleanIf true, return canceled appointments (default false).
directionstringSort order by datetime. ASC (default) or DESC.
emailstringFilter by client email.
firstNamestringFilter by client first name.
lastNamestringFilter by client last name.
maxintegerMax appointments to return.
maxDatestringOnly appointments on/before this date (YYYY-MM-DD or ISO datetime).
minDatestringOnly appointments on/after this date (YYYY-MM-DD or ISO datetime).

No output schema declared.

No examples provided.

acuity_list_blocks ~102

List blocked-off (unavailable) time ranges on the account's calendars. Acuity REST: GET /blocks.

NameTypeReqDescription
calendarIDintegerFilter to a specific calendar id.
maxintegerMax blocks to return.
maxDatestringOnly blocks on/before this date (YYYY-MM-DD or ISO datetime).
minDatestringOnly blocks on/after this date (YYYY-MM-DD or ISO datetime).

No output schema declared.

No examples provided.

acuity_list_calendars ~36

List the account's calendars (staff/resources appointments can be booked on). Acuity REST: GET /calendars.

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

acuity_list_clients ~55

List clients on the account, optionally filtered by a search string (name/email/phone). Acuity REST: GET /clients.

NameTypeReqDescription
searchstringOptional search string to match client name, email, or phone.

No output schema declared.

No examples provided.

acuity_list_forms ~29

List the account's custom intake forms and their fields. Acuity REST: GET /forms.

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

acuity_list_labels ~31

List the appointment labels (colored tags) defined on the account. Acuity REST: GET /labels.

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

acuity_list_orders ~54

List store orders (product / package / gift-certificate purchases). Acuity REST: GET /orders.

NameTypeReqDescription
emailstringFilter orders by buyer email.
maxintegerMax orders to return.

No output schema declared.

No examples provided.

acuity_list_products ~31

List the account's products / packages / gift certificates for sale. Acuity REST: GET /products.

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

acuity_reschedule_appointment ~162

RESCHEDULES an existing appointment to a new time (and optionally a new calendar). This MODIFIES the calendar and, unless suppressed, may send update emails. Acuity REST: PUT /appointments/{id}/reschedule.

NameTypeReqDescription
adminbooleanIf true, reschedule as admin (bypasses availability checks).
calendarIDintegerMove the appointment to this calendar id.
datetimestringyesNew start time in ISO 8601 with offset, e.g. '2026-08-16T10:00:00-0400' (required).
idintegeryesAppointment id to reschedule (required).
noEmailbooleanIf true, suppress reschedule emails.

No output schema declared.

No examples provided.

Common questions

What is the io.usefulapi/acuity-scheduling MCP server?

io.usefulapi/acuity-scheduling is an MCP server listed in the public MCP registry as io.usefulapi/acuity-scheduling. Read appointments, types, calendars and availability; create, cancel or reschedule bookings. This page covers its hosted endpoint (https://acuity-scheduling.usefulapi.io/mcp).

Is the io.usefulapi/acuity-scheduling MCP server safe to use?

io.usefulapi/acuity-scheduling scores 74 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

What tools does the io.usefulapi/acuity-scheduling MCP server expose?

io.usefulapi/acuity-scheduling exposes 18 tools: acuity_list_appointments, acuity_get_appointment, acuity_list_appointment_types, acuity_list_calendars, acuity_availability_dates, and 13 more. Their descriptions and schemas cost roughly 1,627 tokens of context every time the server is loaded.

Does the io.usefulapi/acuity-scheduling MCP server require authentication?

No. We connected to io.usefulapi/acuity-scheduling without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

Is the io.usefulapi/acuity-scheduling MCP server still maintained?

io.usefulapi/acuity-scheduling is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.