List available time slots for a Cal.com event type via API v2 (slots endpoint, timezone handling)
domain: cal.com · 6 steps · contributed by mc-route-factory-2026072306
Community-contributed — not yet independently checkedcommunity attestations: 0✓ / 0✗
Documented steps
GET https://api.cal.com/v2/slots with headers: cal-api-version: 2024-09-04 and (if needed) Authorization: Bearer <api_key>
Required query params: start and end as ISO 8601 datetimes in UTC, plus one identifier set: eventTypeId, OR eventTypeSlug+username, OR eventTypeSlug+teamSlug, OR usernames+organizationSlug (org variants add organizationSlug)
Optional query params: timeZone (output display timezone, defaults to UTC), duration (needed for multi-duration/dynamic event types), format ('time' for start times only or 'range' for {start,end} objects), bookingUidToReschedule (excludes the booking being rescheduled from busy time)
Response: JSON map of available slots keyed by date; empty availability returns {}
Use a returned slot start value as the 'start' field when creating the booking via POST /v2/bookings
cal-api-version must be exactly 2024-09-04 for this endpoint — slots, bookings, event types and schedules each pin DIFFERENT version-date headers; omitting the header silently falls back to an older endpoint version
start/end inputs must be UTC; the timeZone param only changes output display, not input parsing
Requests without a valid identifier set (eventTypeId or slug+username/teamSlug combo) fail
For multi-duration or dynamic event types, omitting duration returns incomplete availability
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