Register for an event

POST/events/:eventId/register

Register for an event. Free tickets are confirmed immediately as UNUSED (or PENDING for approval-based events). For paid tickets, complete payment first via the payment link or prepaid checkout endpoints.

Auth	Login required

Path parameters

eventIdstringrequired

Event ID or slug.

Request body

ticketIdstringrequired

Ticket type ID; required for events that have ticket types.

invitationCodestringoptional

Invitation code; exactly 8 characters. Required for invitation-only tickets.

faceImageUrlstringoptional

Face photo URL; must be a valid URL. Required for events with requiresFacePhoto enabled.

questionAnswersQuestionAnswer[]optional

Array of survey answers; each element has questionId (required) and answer (a non-empty array of strings, each up to 1000 characters). All required questions must be answered.

profileAnswersEntryProfileAnswersoptional

Profile fields collected at registration; keys correspond to the event's entryProfileFields setting.

Response

Field	Type	Description
`entry`	EventEntry	The created entry; state is PENDING for approval-based events.

Request

curl https://api.4s.link/events/EVENT_ID/register \
  -X POST \
  -H "Authorization: Bearer 4s_at_..." \
  -H "Content-Type: application/json" \
  -d '{
  "ticketId": "t1a2b3c4-...",
  "questionAnswers": [
    { "questionId": "q1a2b3c4-...", "answer": "情報収集のため" }
  ]
}'

Example response

{
  "entry": {
    "id": "en1a2b3-...",
    "state": "UNUSED",
    "eventId": "e1f2a3b4-...",
    "ticketId": "t1a2b3c4-...",
    "createdAt": "2026-08-18T00:00:00.000Z"
  }
}