# Select Slot > **ALPHA** > **SECONDARY:** This is an ALPHA feature and needs to be enabled by Cronofy support. Please email [support@cronofy.com](mailto:support@cronofy.com) with the `client_id` of your Application to have it enabled. #### Description Books a time for a [Scheduling Request](/developers/api/scheduling-requests/index.md) by posting the `start` of the chosen slot. This is the second of the two [Time Selection](/developers/api/scheduling-requests/time-selection/index.md) integration operations. Read that page first for the shared [response envelope](/developers/api/scheduling-requests/time-selection/index.md), [result vocabulary](/developers/api/scheduling-requests/time-selection/index.md), [authentication](/developers/api/scheduling-requests/time-selection/index.md), and error shapes. Only a `start` is required: the Scheduling Request already fixes the meeting length, so the `end` is derived from the request's duration. The `start` must match the start of a slot returned by [Available Slots](/developers/api/scheduling-requests/time-selection/available-slots/index.md). Selecting a time here runs the exact same booking as the human booking page: the same calendar writes, notifications, and workflow triggers. On success the response is `202 Accepted`, not `200`: the selection is taken but the calendar write finalizes moments later. The `scheduling_request` rides along and settles from `pending` to `complete` shortly after; query it again whenever you like to see the confirmed event. You do not build this URL. It is returned as the [opaque](/developers/api/scheduling-requests/time-selection/index.md) `simple_select_slot_url` by [Available Slots](/developers/api/scheduling-requests/time-selection/available-slots/index.md), alongside the times. This operation requires the `organizational_unit_scheduler` scope. #### Example Request Send the request to the `simple_select_slot_url` returned by Available Slots, exactly as given. ```http POST {SIMPLE_SELECT_SLOT_URL} HTTP/1.1 Authorization: Bearer {API_KEY} Content-Type: application/json; charset=utf-8 { "start": "2026-09-17T09:30:00Z" } ``` #### Example Response ```http HTTP/1.1 202 Accepted Content-Type: application/json; charset=utf-8 { "integration_operation_result": { "type": "select_slot", "result": "accepted", "integration_operations": {}, "selected_slot": { "start": "2026-09-17T09:30:00Z", "end": "2026-09-17T10:00:00Z" } }, "scheduling_request": { "scheduling_request_id": "srq_7b9784257940f9bbbfcad097", "slot_selection": "pending", "primary_select_url": "https://app.cronofy.com/rts/wZ9tLbN4sWjH6yD1cF0a", "dashboard_url": "https://app.cronofy.com/scheduler/requests/7b9784257940f9bbbfcad097", "summary": "Intro call with Riya Patel" } } ``` #### Request parameters ##### `start` *(required)* A [`Time`](/developers/api/data-types/index.md) in UTC (for example `2026-09-17T09:30:00Z`) of the chosen slot. It must match the `start` of a slot returned by [Available Slots](/developers/api/scheduling-requests/time-selection/available-slots/index.md). The `end` is not accepted; it is derived from the request's fixed duration. A missing or unparseable `start` returns `invalid` (`422`); see [Error responses](#error-responses). ##### `API_KEY` *(required)* An access token for the Organizational Unit with the `organizational_unit_scheduler` scope, or the `client_secret` of the linked Internal Application. See [Authentication](/developers/api/scheduling-requests/time-selection/index.md). #### Response parameters ##### `integration_operation_result` An [`Object`](/developers/api/data-types/index.md) describing the outcome of the operation. See [The response envelope](/developers/api/scheduling-requests/time-selection/index.md). ##### `integration_operation_result.type` A [`String`](/developers/api/data-types/index.md) of `select_slot` for this operation. ##### `integration_operation_result.result` A [`String`](/developers/api/data-types/index.md) outcome, one of: - `accepted`: the selection was taken; the calendar write finalizes moments later (`202`). - `conflict`: a concurrent booking briefly held the slot; retry the same payload (`409`). - `not_possible`: the request's state means this cannot be done (`409`); see `result_detail`. - `invalid`: the input was wrong, such as a missing or malformed `start` (`422`); see the top-level `errors`. ##### `integration_operation_result.result_detail` Present only when `result` is `not_possible`. A [`String`](/developers/api/data-types/index.md) explaining why, one of `slot_unavailable`, `superseded`, `no_longer_possible`, `requires_more_input`, or `configuration_error`. See [result_detail](/developers/api/scheduling-requests/time-selection/index.md). ##### `integration_operation_result.integration_operations` An [`Object`](/developers/api/data-types/index.md) of the actions available next. Empty on an `accepted` selection (nothing is left to do). On a `slot_unavailable` result it carries a `simple_select_slot_url` so you can re-pick without another call. ##### `integration_operation_result.selected_slot` Present when `result` is `accepted`. An [`Object`](/developers/api/data-types/index.md) with the `start` and `end` of the booked slot. ##### `integration_operation_result.selected_slot.start` A [`Time`](/developers/api/data-types/index.md) representing the UTC start of the booked slot. ##### `integration_operation_result.selected_slot.end` A [`Time`](/developers/api/data-types/index.md) representing the UTC end of the booked slot, derived from the request's fixed duration. ##### `scheduling_request` The full Scheduling Request, in the same shape as the [Query](/developers/api/scheduling-requests/query/index.md) response. It travels alongside every envelope response so you can render the current state without a second call. #### Error responses Beyond the shared [errors](/developers/api/scheduling-requests/time-selection/index.md) for authentication, authorization, an unknown token, and rate limiting, this operation can return the following. ##### Chosen time already gone `not_possible` with a `result_detail` of `slot_unavailable` (`409`): the request is still open, but that time has been taken. The response hands back a fresh `available_slots` / `suggested_slots` list and the `simple_select_slot_url`, so you can re-pick without another call. ```json { "integration_operation_result": { "type": "select_slot", "result": "not_possible", "result_detail": "slot_unavailable", "integration_operations": { "simple_select_slot_url": "{SIMPLE_SELECT_SLOT_URL}" }, "available_slots": [ { "start": "2026-09-17T10:00:00Z", "end": "2026-09-17T10:30:00Z" }, { "start": "2026-09-17T14:00:00Z", "end": "2026-09-17T14:30:00Z" } ], "suggested_slots": [ { "start": "2026-09-17T10:00:00Z", "end": "2026-09-17T10:30:00Z" } ] }, "scheduling_request": { ... } } ``` ##### Concurrent booking held the slot `conflict` (`409`): another booking briefly held the target calendars. Nothing is wrong; retry the same payload in a moment. ```json { "integration_operation_result": { "type": "select_slot", "result": "conflict", "integration_operations": {} }, "scheduling_request": { ... } } ``` ##### Missing or malformed start `invalid` (`422`): the `start` was absent or unparseable. A top-level `errors` map (the public API's shape) names the offending field: `errors.required` when missing, `errors.not_recognized` when unparseable. ```json { "integration_operation_result": { "type": "select_slot", "result": "invalid", "integration_operations": {} }, "errors": { "start": [ { "key": "errors.required", "description": "required" } ] }, "scheduling_request": { ... } } ``` ##### Request needs more than a time, or is no longer open `not_possible` with a `result_detail` of `requires_more_input`, `superseded`, `no_longer_possible`, or `configuration_error` (`409`), depending on the request's state. See [result_detail](/developers/api/scheduling-requests/time-selection/index.md) for what each means and how to react. ```json { "integration_operation_result": { "type": "select_slot", "result": "not_possible", "result_detail": "no_longer_possible", "integration_operations": {} }, "scheduling_request": { ... } } ``` --- [Read in HTML](/developers/api/scheduling-requests/time-selection/select-slot/)