Add a session to an event
Schedules an additional session on an existing event. The start and duration are provided; the end is computed server-side as `startAt + durationMinutes`. Returns 404 when the event does not exist or does not belong to your organization. Overlapping sessions are accepted.
Preview release
preview release target — send Billy-API-Version: preview to reach it. Preview has no stability promise: its routes and payloads can change without notice, so pin a dated release before you depend on one. The playground below sends a real POST request to the live API with your own key, and will create or modify actual data.Schedules an additional session on an existing event. The start and duration are provided; the end is computed server-side as startAt + durationMinutes. Returns 404 when the event does not exist or does not belong to your organization. Overlapping sessions are accepted.
Authorization
HTTPBearer API key authentication. Format: Bearer billy:o:<organization_id>:<api_key>
Example: Bearer billy:o:yyyyyyyyyyyyyyyy:xxxxxxxxxxxxxxxxx
In: header
Path Parameters
Header Parameters
Requested API version. Current context: preview.
"preview"Request Body
application/json
TypeScript Definitions
Use the request body type in TypeScript.
A session of POST /v1/events.
Response Body
application/json
application/json
application/json
curl -X POST "https://example.com/v1/events/string/sessions" \ -H "Billy-API-Version: preview" \ -H "Content-Type: application/json" \ -d '{ "startAt": "2026-11-15T20:30:00+01:00", "durationMinutes": 90 }'{ "id": "68799a92-c357-454d-afa5-54ed51f1f98f", "startAt": "2025-03-21T20:30:00+01:00", "durationMinutes": 180}