> ## Documentation Index > Fetch the complete documentation index at: https://docs.classquill.com/llms.txt > Use this file to discover all available pages before exploring further. # Tutor Available Slots > Free bookable time slots for a tutor in [from, to], computed by subtracting the tutor's already-scheduled sessions from their weekly availability rules. 404 if the tutor isn't an accepted member of your org. v1 is deliberately coarse: availability clock-times are treated as UTC and emitted as '...Z'. ## OpenAPI ````yaml /openapi.json get /v1/tutors/{tutor_id}/available-slots openapi: 3.1.0 info: title: ClassQuill Public API description: >- REST API for ClassQuill tutoring organisations. Pipe your sessions, invoices, payments, tutor earnings, students, and more into your own tools. Most endpoints are reads; a focused set of writes (each gated by a *:write scope) create or update data, including creating student/tutor/parent accounts. Authenticate every request with an org API key: Authorization: Token token=ei_live_... Mint keys in the ClassQuill app under Settings → Developers. version: 1.0.0 servers: [] security: - ApiKeyAuth: [] tags: - name: General - name: Sessions - name: Tutors - name: Students & Parents - name: Billing - name: Curriculum - name: Coursework - name: Operations - name: Pricing - name: Bookings - name: Blog - name: Reports paths: /v1/tutors/{tutor_id}/available-slots: get: tags: - Tutors summary: Tutor Available Slots description: >- Free bookable time slots for a tutor in [from, to], computed by subtracting the tutor's already-scheduled sessions from their weekly availability rules. 404 if the tutor isn't an accepted member of your org. v1 is deliberately coarse: availability clock-times are treated as UTC and emitted as '...Z'. operationId: tutor_available_slots_v1_tutors__tutor_id__available_slots_get parameters: - name: tutor_id in: path required: true schema: type: string description: Tutor UUID title: Tutor Id description: Tutor UUID - name: from in: query required: true schema: type: string description: Window start, ISO date e.g. 2026-07-01 title: From description: Window start, ISO date e.g. 2026-07-01 - name: to in: query required: true schema: type: string description: Window end, ISO date e.g. 2026-07-07 title: To description: Window end, ISO date e.g. 2026-07-07 - name: duration in: query required: false schema: type: integer maximum: 600 minimum: 1 description: Slot length in minutes (default 60) default: 60 title: Duration description: Slot length in minutes (default 60) responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/AvailableSlots' '401': description: Missing, malformed, revoked, or expired credentials. content: application/json: schema: $ref: '#/components/schemas/ApiError' '403': description: The credential lacks the scope this endpoint requires. content: application/json: schema: $ref: '#/components/schemas/ApiError' '404': description: >- Not found — the record doesn't exist or belongs to another organisation. content: application/json: schema: $ref: '#/components/schemas/ApiError' '422': description: Validation error — `error.details.errors` lists the fields. content: application/json: schema: $ref: '#/components/schemas/ApiError' '429': description: >- Rate limit exceeded — honour Retry-After and the RateLimit-* headers. content: application/json: schema: $ref: '#/components/schemas/ApiError' components: schemas: AvailableSlots: properties: tutor_id: type: string title: Tutor Id duration_minutes: type: integer title: Duration Minutes from_date: type: string title: From Date to_date: type: string title: To Date slots: items: $ref: '#/components/schemas/AvailableSlot' type: array title: Slots default: [] type: object required: - tutor_id - duration_minutes - from_date - to_date title: AvailableSlots description: >- GET /v1/tutors/{tutor_id}/available-slots — free slots in the window, computed by subtracting scheduled sessions from the tutor's weekly availability rules. ApiError: description: Canonical error envelope for every /v1 error response (4xx/5xx). properties: error: $ref: '#/components/schemas/ApiErrorBody' required: - error title: ApiError type: object AvailableSlot: properties: starts_at: type: string title: Starts At ends_at: type: string title: Ends At type: object required: - starts_at - ends_at title: AvailableSlot description: One free bookable time slot from GET /v1/tutors/{id}/available-slots. ApiErrorBody: description: The `error` object every /v1 error response carries. properties: code: description: >- Stable machine-readable error code: bad_request, unauthorized, forbidden, not_found, conflict, validation_error, rate_limited, or internal_error. examples: - not_found title: Code type: string message: description: Human-readable explanation, safe to surface to end users. examples: - Session not found title: Message type: string status: description: The HTTP status code, repeated in the body. examples: - 404 title: Status type: integer details: additionalProperties: true description: >- Error-specific context. 422 carries the field errors under `errors`; 429 carries `retry_after_seconds`. title: Details type: object required: - code - message - status title: ApiErrorBody type: object securitySchemes: ApiKeyAuth: type: apiKey in: header name: Authorization description: Org API key as `Token token=ei_live_...` ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.