> ## Documentation Index > Fetch the complete documentation index at: https://docs.famulor.io/llms.txt > Use this file to discover all available pages before exploring further. # List free slots > List the free start times of one active event type for a date range (at most 28 days; dates default to the workspace time zone). Past times and times after `bookable_until` are never returned. Pass a returned slot unchanged as `start` to *Create a booking* or *Reschedule a booking*; when moving a booking, pass `exclude_booking_id` so its own time does not block nearby slots. Returns `409` instead of `200` when the event type is turned off, or when the workspace has not set up its public booking address yet. A `503` here can mean either request protection is temporarily unavailable (`internal_error`) or the availability engine itself failed to load (`service_unavailable`, message "Could not load availability") — see *AvailabilityOrProtectionUnavailable*. **Required scope:** `bookings:read` (keys without scope restrictions have full access). ## OpenAPI ````yaml /api-reference/openapi.json get /booking-event-types/{id}/slots openapi: 3.1.0 info: title: Famulor API version: 1.0.0 description: >- REST API for Famulor. Authenticate with an API key (`fam_...`, created under **Settings → API Keys**) or an OAuth 2.0 access token (`fam_at_...`) as a Bearer token. Every response uses a consistent envelope: `{ "data": ... , "meta": { ... } }` on success and `{ "error": { "code", "message" } }` on failure. List endpoints paginate with `?limit=` (default 50, max 200) and `?offset=`; `meta.pagination.total` carries the total match count. REST operations require API Access through the workspace plan or a recurring add-on. Without it, regular operations return `403 api_access_required`. The invoice-payment and billing-portal operations remain available with a valid `billing:write` credential after a failed plan payment so an authorized owner, admin, or billing member can recover billing. The same customer-facing capabilities are available as MCP tools at `https://app.famulor.io/mcp` (Model Context Protocol, streamable HTTP) using the same credentials, scopes, and workspace access. MCP availability is controlled separately by Connect AI / MCP, not by API Access. servers: - url: https://app.famulor.io/api/v1 description: Hosted platform. - url: https://{domain}/api/v1 description: White-label tenant domain — same paths, tenant branding. variables: domain: default: app.famulor.io description: Your white-label tenant domain. security: - bearerAuth: [] tags: - name: Account description: Self-inspection of the calling credential. - name: Migrations description: Preview and import data from supported legacy platforms. - name: Assistants description: Create and manage voice assistants. - name: Tools description: >- Reusable tools (HTTP APIs and external MCP servers) assistants can call mid-conversation. - name: Voices description: Browse the text-to-speech voice library. - name: Calls description: Start outbound calls and read call history, transcripts and recordings. - name: History description: Unified conversation history across calls, messaging and assistant emails. - name: Campaigns description: Outbound calling campaigns with a compliant power dialer. - name: Leads description: Manage Audience contacts across campaigns, channels and Call QA metrics. - name: Segments description: >- Saved, dynamic lead filters — reusable audience definitions used for Audience search and campaign lead assignment. - name: Suppression description: Cross-channel marketing opt-outs and active workspace suppression records. - name: Callbacks description: >- Scheduled callbacks booked by the Schedule callback tool across voice, chat, and email. - name: Phone Numbers description: Marketplace numbers and customer-provided numbers. - name: Famulor Loop description: >- Personal business-phone access, directory, presence, devices, and Loop call recents. - name: SIP Trunks description: Bring your own SIP provider and numbers. - name: Carrier Connections description: Connect a supported carrier account and import its existing phone numbers. - name: Knowledge Bases description: RAG knowledge bases and documents for assistants. - name: Settings description: Workspace-level settings such as caller-memory defaults. - name: Billing description: Balance and minutes ledger of the key owner. - name: Automations description: >- Native workspace automations — list, create, update, trigger. Plan gate: automation_platform. - name: Milian Missions description: Recurring jobs that Milian runs unattended on schedule. - name: Integrations description: >- Calendar integrations (Cal.com, Calendly, Acuity Scheduling, Google Calendar, Outlook, native booking engine). Assign them to assistants to provide availability and booking tools, plus provider-supported appointment lookup, cancellation, and rescheduling. - name: Bookings description: >- Native booking engine — event types with weekly availability, public booking pages at /book/{workspace}/{slug}, and the bookings they produce. - name: Dashboards description: >- Custom analytics dashboards, reusable widgets, and tenant-scoped performance analytics. Requires the custom_dashboards plan feature. - name: Catalog description: >- Read-only platform catalogs — available models, supported assistant languages, and prompt templates. - name: Simulations description: Assistant simulation tests (plan-gated). - name: Versions description: Assistant configuration version history. - name: Caller IDs description: Outbound caller ID verification. - name: Widgets description: Web widget connectors. - name: Messaging description: >- Telegram, Slack, and Messenger text bots linked to assistants (Chat SDK). Includes conversation delay, inactivity end, and conversation-ended webhooks. - name: QA description: Cohort AI Quality Assurance runs over call transcripts. - name: White Label description: >- Manage white-label customer accounts, defaults, credit transfers and customer plan offers. Each endpoint documents its required scope and workspace eligibility. - name: API Keys description: >- Self-service API keys for the calling workspace or a same-brand workspace where the credential's user is owner/admin. A key can only mint further keys with a scope subset of its own. - name: Workspaces description: >- List visible workspaces, create an additional workspace for the key owner, and mint a dedicated credential for a selected owner/admin workspace. - name: SMS description: Outbound SMS from workspace phone numbers. paths: /booking-event-types/{id}/slots: get: tags: - Bookings summary: List free slots description: >- List the free start times of one active event type for a date range (at most 28 days; dates default to the workspace time zone). Past times and times after `bookable_until` are never returned. Pass a returned slot unchanged as `start` to *Create a booking* or *Reschedule a booking*; when moving a booking, pass `exclude_booking_id` so its own time does not block nearby slots. Returns `409` instead of `200` when the event type is turned off, or when the workspace has not set up its public booking address yet. A `503` here can mean either request protection is temporarily unavailable (`internal_error`) or the availability engine itself failed to load (`service_unavailable`, message "Could not load availability") — see *AvailabilityOrProtectionUnavailable*. **Required scope:** `bookings:read` (keys without scope restrictions have full access). operationId: listBookingSlots parameters: - name: id in: path required: true schema: type: string format: uuid description: Event type ID - name: start in: query schema: type: string format: date description: Start of the date range (YYYY-MM-DD); default today. - name: end in: query schema: type: string format: date description: >- End of the date range (YYYY-MM-DD); default start + 6 days, max 28 days. - name: timezone in: query schema: type: string description: >- IANA time zone for the returned range and slots; default the workspace time zone. - name: exclude_booking_id in: query schema: type: string format: uuid description: >- Exclude this booking's own time from busy calculations (use when rescheduling it). responses: '200': description: Free slots of the event type. content: application/json: schema: type: object required: - data properties: data: $ref: '#/components/schemas/BookingSlots' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '409': $ref: '#/components/responses/Conflict' '429': $ref: '#/components/responses/RateLimited' '503': $ref: '#/components/responses/AvailabilityOrProtectionUnavailable' components: schemas: BookingSlots: type: object properties: event_type_id: type: string format: uuid event_type_name: type: string duration_min: type: integer slot_increment_min: type: - integer - 'null' timezone: type: string start: type: string format: date description: Start of the resolved date range. end: type: string format: date description: End of the resolved date range. bookable_until: type: string format: date-time description: The event type's booking horizon (now + max_days_ahead). slots: type: array items: type: string format: date-time description: Free start times, ISO 8601 UTC, ascending. requirements: $ref: '#/components/schemas/BookingSlotRequirements' BookingSlotRequirements: type: object description: What create_booking / POST /bookings needs for this event type. properties: email_required: type: boolean phone_required: type: boolean fields: type: array items: $ref: '#/components/schemas/BookingField' location_type: type: - string - 'null' ErrorEnvelope: type: object description: Error envelope returned by every /api/v1 endpoint on failure. required: - error properties: error: type: object required: - code - message properties: code: type: string enum: - unauthorized - forbidden - api_access_required - not_found - invalid_request - rate_limited - conflict - telephony_configuration_error - telephony_unavailable - destination_forbidden - internal_error - service_unavailable description: >- Stable, machine-readable error code. `service_unavailable` is returned by POST /bookings and GET /booking-event-types/{id}/slots specifically when the availability engine could not be reached (see AvailabilityOrProtectionUnavailable). message: type: string description: Human-readable description of the error. BookingField: type: object description: >- A custom booking question asked on the public booking page. Answers are keyed by `id` on a booking's `answers` object and can be prefilled on the public booking page via the matching URL parameter. required: - id - type - label - required properties: id: type: string pattern: ^[a-z][a-z0-9_-]{0,39}$ description: >- Identifier, unique within the event type. Doubles as the answers key and the URL prefill parameter, e.g. ?company=Acme. Reserved and not allowed: name, email, phone, notes, start, timezone, website, answers, call_id. type: type: string enum: - email - phone - address - short_text - number - long_text - select - multiselect - multiple_emails - checkbox_group - radio_group - checkbox - url description: Input type shown on the booking page. label: type: string minLength: 1 maxLength: 120 description: Question label shown to the visitor. placeholder: type: string maxLength: 120 required: type: boolean description: Whether the visitor must answer this question before booking. options: type: array items: type: string maxLength: 80 minItems: 1 maxItems: 50 uniqueItems: true description: >- Choices, in display order. Required for select, multiselect, checkbox_group and radio_group; unused for other types. disable_if_prefilled: type: boolean description: >- When true, the field becomes read-only on the public page if its value was prefilled via URL parameter. responses: BadRequest: description: Invalid request body or parameters. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: invalid_request message: '"to_number" is required (E.164 format, e.g. +4930123456).' Unauthorized: description: Missing, invalid, expired or revoked API key / access token. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: unauthorized message: Invalid API key. Forbidden: description: >- The credential lacks the required scope or role, or the workspace does not have the required capability. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' examples: scopeDenied: summary: Required scope is missing value: error: code: forbidden message: >- This API key is missing the required scope "assistants:write". apiAccessRequired: summary: API Access is not available value: error: code: api_access_required message: >- API Access is not available for this workspace. Review Settings → Plan. NotFound: description: Resource not found (or it belongs to another workspace). content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: not_found message: Assistant not found Conflict: description: The resource is in a conflicting state. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: conflict message: Campaign is not running. RateLimited: description: Too many requests. Retry after the indicated delay. headers: Retry-After: description: Seconds to wait before retrying. schema: type: integer minimum: 1 content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: rate_limited message: Too many requests. Retry after the indicated delay. AvailabilityOrProtectionUnavailable: description: >- Either request protection is temporarily unavailable (code `internal_error`), or, specifically for this endpoint, the availability engine could not be reached (code `service_unavailable`, message "Could not load availability"). Retry after a short delay in both cases. headers: Retry-After: description: Seconds to wait before retrying. schema: type: integer minimum: 1 content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' examples: requestProtectionUnavailable: summary: Request protection unavailable value: error: code: internal_error message: Request protection is temporarily unavailable. availabilityUnavailable: summary: Availability engine failed to load value: error: code: service_unavailable message: Could not load availability securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: API key description: >- API key (`fam_...`, created under **Settings → API Keys**) or an OAuth 2.0 access token (`fam_at_...`). REST operations also require API Access for the credential's workspace. Keys can be restricted to scopes such as `assistants:read`, `calls:write`, `campaigns:write`, `automations:read`, `dashboards:read`, `dashboards:write`, `leads:write`, `segments:write`, `loop:read`, `loop:write`, `phone_numbers:write`, `sip_trunks:write`, `knowledge:write`, `voices:read`, `billing:read`, `billing:write`, `settings:write`, `platform:read`, `platform:write`; a `*:write` scope implies the matching `*:read`. Automation and dashboard endpoints also accept the legacy `calls:*` scope. Keys without scope restrictions have full access within the workspace's available capabilities. ````