# Cancel an appointment

Cancels an appointment as a command: the response is the appointment with
`status: "cancelled"` and `cancelled_at` set. Optionally stores a `reason` and
whether to notify the client.
Requires `Idempotency-Key`. Cancelling an already cancelled appointment with the same
key is a no-op returning the same result.
A cancelled appointment stays readable: `getAppointment` returns it with
`status: "cancelled"` rather than `404`, and `listAppointments` keeps returning it, so a
client synchronising the journal sees the cancellation instead of silently losing the row.
Filter on the `status` field to hide them. In a visit built from several appointments,
cancelling one does not cancel the visit: the remaining appointments and any payments
already recorded stay, and `amount_to_pay_minor` is recomputed when the visit is read.

Endpoint: POST /locations/{location_id}/appointments/{appointment_id}/cancel
Version: 3.0.0-preview
Security: OAuth2, ApiKey

## Security:

  - `OAuth2` (unknown)
    oauth2 scopes: appointments:write

  - `ApiKey` (unknown)
    http bearer

## Path parameters:

  - `location_id` (integer, required)
    Identifier of the Location. Verified against the credential on every call — a Location the credential cannot access responds with `404`.

  - `appointment_id` (integer, required)
    Identifier of the appointment.

## Header parameters:

  - `Idempotency-Key` (string, required)
    Client-generated unique key for this logical request (UUID recommended). A retry with the same key and body returns the original result; the same key with a different body fails with `409 idempotency_key_reused`. Keys are retained at least 24 hours and are scoped to credential, Location, and operation; after expiry the value may be reused for a new logical request.

## Request fields (application/json):

  - `reason` (string)
    Free-form cancellation reason stored on the appointment.

  - `notify_client` (boolean)
    Whether to send the client a cancellation notification.

## Response 200:

  - `200` (unknown)
    The cancelled appointment.

## Response 200 fields (application/json):

  - `id` (integer, required)

  - `object` (string, required)
    Enum: "appointment"

  - `location_id` (integer, required)

  - `client_id` (integer | null)
    `null` only on appointments without a client.

  - `visit_id` (integer | null)
    Billing visit of this appointment.

  - `team_member_id` (integer, required)

  - `service_ids` (array, required)

  - `resource_instance_ids` (array)
    Resource instances occupied by the appointment.

  - `status` (string, required)
    Status of an appointment. `waiting` — scheduled, not yet confirmed; `confirmed` — confirmed by the client; `arrived` — the client attended (terminal "done" state); `no_show` — the client did not attend; `cancelled` — cancelled via the cancel command (never set through the status command).
    Enum: "waiting", "confirmed", "arrived", "no_show", "cancelled"

  - `starts_at` (string, required)
    RFC 3339 with the Location's local UTC offset.

  - `ends_at` (string)
    RFC 3339 with the Location's local UTC offset.

  - `duration_seconds` (integer, required)

  - `is_paid` (boolean)
    Whether the visit of this appointment is fully paid.

  - `comment` (string | null)

  - `cancelled_at` (string | null)
    UTC; set by the cancel command.

  - `cancellation_reason` (string | null)

  - `client` (object)
    A client of the Location. Contact fields (`phone`, `email`, `additional_phone`) are PII: without `clients:read_contact` plus the subject contact permission they are returned as `null` and their names are listed in `redacted_fields` instead of exposing a contact string.

  - `client.id` (integer, required)

  - `client.object` (string, required)
    Enum: "client"

  - `client.name` (string, required)

  - `client.surname` (string | null)

  - `client.patronymic` (string | null)

  - `client.display_name` (string)

  - `client.phone` (string | null, required)
    International phone number. `null` when absent or withheld — see `redacted_fields`.

  - `client.additional_phone` (string | null)
    Additional phone number. `null` when absent or withheld — see `redacted_fields`.

  - `client.email` (string | null)
    Email address. `null` when absent or withheld — see `redacted_fields`.

  - `client.birth_date` (string | null)

  - `client.comment` (string | null)
    Private note about the client; requires comment access.

  - `client.discount` (number | null)
    Personal discount, percent.

  - `client.visits_count` (integer)

  - `client.first_visit_at` (string | null)
    Location-local offset.

  - `client.last_visit_at` (string | null)
    Location-local offset.

  - `client.currency` (string)
    ISO 4217, server-controlled by the Location.

  - `client.created_at` (string)
    UTC.

  - `client.updated_at` (string)
    UTC.

  - `client.sold_amount_minor` (integer)
    Lifetime paid total, integer minor units of the Location currency.

  - `client.redacted_fields` (array)
    Names of fields withheld by the PII policy for this object, for example
`["phone", "email"]`. A withheld contact is always returned as `null` — never as a
masked or empty string, so an integration cannot write a mask back. An empty array
means nothing was withheld and a `null` value simply means no value is stored.

  - `team_member` (object)
    A Team Member of the Location. Personal contact data of Team Members is not exposed in the preview scope.

  - `team_member.id` (integer, required)

  - `team_member.object` (string, required)
    Enum: "team_member"

  - `team_member.name` (string, required)

  - `team_member.specialization` (string, required)
    Public profession label shown to clients (for example in online booking).

  - `team_member.position_id` (integer | null)
    Position from `listPositions`.

  - `team_member.service_ids` (array)
    Services this Team Member can be scheduled for. Written through `updateTeamMemberServices`.

  - `team_member.is_bookable` (boolean)
    Derived — whether the member can currently receive appointments.

  - `team_member.is_billable` (boolean)
    Whether this Team Member occupies a paid seat in the Location's licence, which is what
the Location is charged for. A non-billable member cannot hold schedule access, so
`is_bookable` is always `false` for one. Locations still on the older licensing model
report `false` here and ignore the field on write — there the paid seat count follows
schedule access instead.

  - `team_member.dismissal_date` (string | null)
    Last working day set by `dismissTeamMember`, `YYYY-MM-DD` in the Location timezone; `null` while employed.

  - `team_member.dismissal_reason` (string | null)
    Reason given on dismissal; `null` while employed.

  - `team_member.created_at` (string)
    UTC.

  - `team_member.updated_at` (string)
    UTC.

  - `created_at` (string)
    UTC.

  - `updated_at` (string)
    UTC.

## Response 200 headers (application/json):

  - `RateLimit-Remaining` (integer)
    Requests left in the most constrained policy window that applies to this request.

  - `RateLimit-Reset` (integer)
    On `429`, seconds until the most constrained policy frees up; it equals `Retry-After` there.
On a successful response it reports the **length** of that policy's window rather than the
time left in the current one, so treat it as the window size, not as a countdown — the
counter to pace against is `RateLimit-Remaining`.

  - `RateLimit-Policy` (string)
    Most constrained policy applied to the request, as `<limit>;w=<window in seconds>`.
    Example: 10;w=60

  - `X-Request-Id` (string)
    Request identifier for support and log correlation.

## Response 400:

  - `400` (unknown)
    Client error without a more specific registered code (`bad_request` — status default for
bare 400 and unknown 4xx), or protocol/syntax failure (`malformed_request` — broken JSON /
unparseable body only; must be thrown explicitly, never used as a synonym for every 400).
Semantic field validation is `422 validation_failed`, not 400.

## Response 400 fields (application/problem+json):

  - `type` (string, required)
    Stable URL identifying the problem type; links to documentation.

  - `title` (string, required)
    Human-readable summary of the problem type.

  - `status` (integer, required)
    HTTP status code of this response.

  - `detail` (string)
    Human-readable explanation of this occurrence.

  - `instance` (string, required)
    Request identifier for support and log correlation.

  - `code` (string, required)
    Stable machine-readable reason code.

  - `errors` (array)
    Field-level issues (present on validation problems).

  - `errors.code` (string, required)
    Stable machine-readable reason for this field.

  - `errors.pointer` (string, required)
    JSON Pointer for `body`; parameter name for `query`, `path`, or `header`.

  - `errors.message` (string, required)
    Human-readable explanation.

  - `errors.source` (string, required)
    Where the invalid value came from.
    Enum: "body", "query", "path", "header"

## Response 400 headers (application/problem+json):

  - `X-Request-Id` (string)
    Request identifier for support and log correlation.

## Response 401:

  - `401` (unknown)
    The request has no valid Bearer credential (`invalid_token`).

## Response 401 fields (application/problem+json):

  - `type` (string, required)
    Stable URL identifying the problem type; links to documentation.

  - `title` (string, required)
    Human-readable summary of the problem type.

  - `status` (integer, required)
    HTTP status code of this response.

  - `detail` (string)
    Human-readable explanation of this occurrence.

  - `instance` (string, required)
    Request identifier for support and log correlation.

  - `code` (string, required)
    Stable machine-readable reason code.

  - `errors` (array)
    Field-level issues (present on validation problems).

  - `errors.code` (string, required)
    Stable machine-readable reason for this field.

  - `errors.pointer` (string, required)
    JSON Pointer for `body`; parameter name for `query`, `path`, or `header`.

  - `errors.message` (string, required)
    Human-readable explanation.

  - `errors.source` (string, required)
    Where the invalid value came from.
    Enum: "body", "query", "path", "header"

## Response 401 headers (application/problem+json):

  - `WWW-Authenticate` (string)
    Bearer challenge with the URL of the protected resource metadata (RFC 9728 §5.1),
where the client finds the authorization server.
    Example: Bearer resource_metadata="https://api.alteg.io/.well-known/oauth-protected-resource/api/v3"

  - `X-Request-Id` (string)
    Request identifier for support and log correlation.

## Response 403:

  - `403` (unknown)
    The token lacks the required scope (`missing_scope`), the scope is present but the token subject lacks the business permission (`permission_denied`), or the Location has no active license (`subscription_inactive`).

## Response 403 fields (application/problem+json):

  - `type` (string, required)
    Stable URL identifying the problem type; links to documentation.

  - `title` (string, required)
    Human-readable summary of the problem type.

  - `status` (integer, required)
    HTTP status code of this response.

  - `detail` (string)
    Human-readable explanation of this occurrence.

  - `instance` (string, required)
    Request identifier for support and log correlation.

  - `code` (string, required)
    Stable machine-readable reason code.

  - `errors` (array)
    Field-level issues (present on validation problems).

  - `errors.code` (string, required)
    Stable machine-readable reason for this field.

  - `errors.pointer` (string, required)
    JSON Pointer for `body`; parameter name for `query`, `path`, or `header`.

  - `errors.message` (string, required)
    Human-readable explanation.

  - `errors.source` (string, required)
    Where the invalid value came from.
    Enum: "body", "query", "path", "header"

## Response 403 headers (application/problem+json):

  - `WWW-Authenticate` (string)
    Only on `missing_scope`: Bearer challenge with `error="insufficient_scope"`, the scope the
operation requires and the URL of the protected resource metadata (RFC 6750 §3.1, RFC 9728 §5.1).
    Example: Bearer error="insufficient_scope", scope="team_members:read", resource_metadata="https://api.alteg.io/.well-known/oauth-protected-resource/api/v3"

  - `X-Request-Id` (string)
    Request identifier for support and log correlation.

## Response 404:

  - `404` (unknown)
    The resource does not exist or is hidden by tenant policy. Prefer a resource-specific
code (`appointment_not_found`, `location_not_found`, …). Routing/gate/unknown-path 404s
use the generic `resource_not_found` (same shape, so "no pin" and "missing" are not distinguished).

## Response 404 fields (application/problem+json):

  - `type` (string, required)
    Stable URL identifying the problem type; links to documentation.

  - `title` (string, required)
    Human-readable summary of the problem type.

  - `status` (integer, required)
    HTTP status code of this response.

  - `detail` (string)
    Human-readable explanation of this occurrence.

  - `instance` (string, required)
    Request identifier for support and log correlation.

  - `code` (string, required)
    Stable machine-readable reason code.

  - `errors` (array)
    Field-level issues (present on validation problems).

  - `errors.code` (string, required)
    Stable machine-readable reason for this field.

  - `errors.pointer` (string, required)
    JSON Pointer for `body`; parameter name for `query`, `path`, or `header`.

  - `errors.message` (string, required)
    Human-readable explanation.

  - `errors.source` (string, required)
    Where the invalid value came from.
    Enum: "body", "query", "path", "header"

## Response 404 headers (application/problem+json):

  - `X-Request-Id` (string)
    Request identifier for support and log correlation.

## Response 406:

  - `406` (unknown)
    Requested `Accept` media type cannot be satisfied (`not_acceptable`).

## Response 406 fields (application/problem+json):

  - `type` (string, required)
    Stable URL identifying the problem type; links to documentation.

  - `title` (string, required)
    Human-readable summary of the problem type.

  - `status` (integer, required)
    HTTP status code of this response.

  - `detail` (string)
    Human-readable explanation of this occurrence.

  - `instance` (string, required)
    Request identifier for support and log correlation.

  - `code` (string, required)
    Stable machine-readable reason code.

  - `errors` (array)
    Field-level issues (present on validation problems).

  - `errors.code` (string, required)
    Stable machine-readable reason for this field.

  - `errors.pointer` (string, required)
    JSON Pointer for `body`; parameter name for `query`, `path`, or `header`.

  - `errors.message` (string, required)
    Human-readable explanation.

  - `errors.source` (string, required)
    Where the invalid value came from.
    Enum: "body", "query", "path", "header"

## Response 406 headers (application/problem+json):

  - `X-Request-Id` (string)
    Request identifier for support and log correlation.

## Response 409:

  - `409` (unknown)
    The `Idempotency-Key` was already used with a different body (`idempotency_key_reused`), or the first request with this key is still running (`idempotency_request_in_progress`, retry after `Retry-After`).

## Response 409 fields (application/problem+json):

  - `type` (string, required)
    Stable URL identifying the problem type; links to documentation.

  - `title` (string, required)
    Human-readable summary of the problem type.

  - `status` (integer, required)
    HTTP status code of this response.

  - `detail` (string)
    Human-readable explanation of this occurrence.

  - `instance` (string, required)
    Request identifier for support and log correlation.

  - `code` (string, required)
    Stable machine-readable reason code.

  - `errors` (array)
    Field-level issues (present on validation problems).

  - `errors.code` (string, required)
    Stable machine-readable reason for this field.

  - `errors.pointer` (string, required)
    JSON Pointer for `body`; parameter name for `query`, `path`, or `header`.

  - `errors.message` (string, required)
    Human-readable explanation.

  - `errors.source` (string, required)
    Where the invalid value came from.
    Enum: "body", "query", "path", "header"

## Response 409 headers (application/problem+json):

  - `X-Request-Id` (string)
    Request identifier for support and log correlation.

  - `Retry-After` (integer)
    Seconds to wait before retrying.

## Response 415:

  - `415` (unknown)
    Unsupported request media type.

## Response 415 fields (application/problem+json):

  - `type` (string, required)
    Stable URL identifying the problem type; links to documentation.

  - `title` (string, required)
    Human-readable summary of the problem type.

  - `status` (integer, required)
    HTTP status code of this response.

  - `detail` (string)
    Human-readable explanation of this occurrence.

  - `instance` (string, required)
    Request identifier for support and log correlation.

  - `code` (string, required)
    Stable machine-readable reason code.

  - `errors` (array)
    Field-level issues (present on validation problems).

  - `errors.code` (string, required)
    Stable machine-readable reason for this field.

  - `errors.pointer` (string, required)
    JSON Pointer for `body`; parameter name for `query`, `path`, or `header`.

  - `errors.message` (string, required)
    Human-readable explanation.

  - `errors.source` (string, required)
    Where the invalid value came from.
    Enum: "body", "query", "path", "header"

## Response 415 headers (application/problem+json):

  - `X-Request-Id` (string)
    Request identifier for support and log correlation.

## Response 422:

  - `422` (unknown)
    Semantic validation failed (`validation_failed`); field-level details are in `errors[]`. Merge-patch violations use `field_not_nullable` / `field_immutable`.

## Response 422 fields (application/problem+json):

  - `type` (string, required)
    Stable URL identifying the problem type; links to documentation.

  - `title` (string, required)
    Human-readable summary of the problem type.

  - `status` (integer, required)
    HTTP status code of this response.

  - `detail` (string)
    Human-readable explanation of this occurrence.

  - `instance` (string, required)
    Request identifier for support and log correlation.

  - `code` (string, required)
    Stable machine-readable reason code.

  - `errors` (array)
    Field-level issues (present on validation problems).

  - `errors.code` (string, required)
    Stable machine-readable reason for this field.

  - `errors.pointer` (string, required)
    JSON Pointer for `body`; parameter name for `query`, `path`, or `header`.

  - `errors.message` (string, required)
    Human-readable explanation.

  - `errors.source` (string, required)
    Where the invalid value came from.
    Enum: "body", "query", "path", "header"

## Response 422 headers (application/problem+json):

  - `X-Request-Id` (string)
    Request identifier for support and log correlation.

## Response 429:

  - `429` (unknown)
    Rate limit exceeded (`rate_limit_exceeded`). Retry after `Retry-After`.

## Response 429 fields (application/problem+json):

  - `type` (string, required)
    Stable URL identifying the problem type; links to documentation.

  - `title` (string, required)
    Human-readable summary of the problem type.

  - `status` (integer, required)
    HTTP status code of this response.

  - `detail` (string)
    Human-readable explanation of this occurrence.

  - `instance` (string, required)
    Request identifier for support and log correlation.

  - `code` (string, required)
    Stable machine-readable reason code.

  - `errors` (array)
    Field-level issues (present on validation problems).

  - `errors.code` (string, required)
    Stable machine-readable reason for this field.

  - `errors.pointer` (string, required)
    JSON Pointer for `body`; parameter name for `query`, `path`, or `header`.

  - `errors.message` (string, required)
    Human-readable explanation.

  - `errors.source` (string, required)
    Where the invalid value came from.
    Enum: "body", "query", "path", "header"

## Response 429 headers (application/problem+json):

  - `Retry-After` (integer)
    Seconds to wait before retrying.

  - `RateLimit-Remaining` (integer)
    Requests left in the most constrained policy window that applies to this request.

  - `RateLimit-Reset` (integer)
    On `429`, seconds until the most constrained policy frees up; it equals `Retry-After` there.
On a successful response it reports the **length** of that policy's window rather than the
time left in the current one, so treat it as the window size, not as a countdown — the
counter to pace against is `RateLimit-Remaining`.

  - `RateLimit-Policy` (string)
    Most constrained policy applied to the request, as `<limit>;w=<window in seconds>`.
    Example: 10;w=60

  - `X-Request-Id` (string)
    Request identifier for support and log correlation.

## Response 500:

  - `500` (unknown)
    Unexpected server error (`internal_error`).

## Response 500 fields (application/problem+json):

  - `type` (string, required)
    Stable URL identifying the problem type; links to documentation.

  - `title` (string, required)
    Human-readable summary of the problem type.

  - `status` (integer, required)
    HTTP status code of this response.

  - `detail` (string)
    Human-readable explanation of this occurrence.

  - `instance` (string, required)
    Request identifier for support and log correlation.

  - `code` (string, required)
    Stable machine-readable reason code.

  - `errors` (array)
    Field-level issues (present on validation problems).

  - `errors.code` (string, required)
    Stable machine-readable reason for this field.

  - `errors.pointer` (string, required)
    JSON Pointer for `body`; parameter name for `query`, `path`, or `header`.

  - `errors.message` (string, required)
    Human-readable explanation.

  - `errors.source` (string, required)
    Where the invalid value came from.
    Enum: "body", "query", "path", "header"

## Response 500 headers (application/problem+json):

  - `X-Request-Id` (string)
    Request identifier for support and log correlation.

## Response 503:

  - `503` (unknown)
    A dependency required for safe processing (e.g. the idempotency store) is unavailable; the write was **not** performed (`dependency_unavailable`). Retry with the same `Idempotency-Key` after a backoff.

## Response 503 fields (application/problem+json):

  - `type` (string, required)
    Stable URL identifying the problem type; links to documentation.

  - `title` (string, required)
    Human-readable summary of the problem type.

  - `status` (integer, required)
    HTTP status code of this response.

  - `detail` (string)
    Human-readable explanation of this occurrence.

  - `instance` (string, required)
    Request identifier for support and log correlation.

  - `code` (string, required)
    Stable machine-readable reason code.

  - `errors` (array)
    Field-level issues (present on validation problems).

  - `errors.code` (string, required)
    Stable machine-readable reason for this field.

  - `errors.pointer` (string, required)
    JSON Pointer for `body`; parameter name for `query`, `path`, or `header`.

  - `errors.message` (string, required)
    Human-readable explanation.

  - `errors.source` (string, required)
    Where the invalid value came from.
    Enum: "body", "query", "path", "header"

## Response 503 headers (application/problem+json):

  - `X-Request-Id` (string)
    Request identifier for support and log correlation.

## Response 400 examples:

  - `Generic client reject (status default)` (unknown)

  - `Broken JSON / protocol only` (unknown)

## Response 403 examples:

  - `Token scope is insufficient` (unknown)

  - `Subject lacks the business permission` (unknown)

  - `Location license is not active` (unknown)

## Response 404 examples:

  - `Generic 404 (routing / gate / hidden)` (unknown)

  - `Resource-specific 404` (unknown)

## Response 409 examples:

  - `Same key, different body` (unknown)

  - `First request still in progress` (unknown)