Sessions, abstracts & composition

Sessions and CFP abstract submissions share the same API resource. Use is_abstract to tell them apart.

`is_abstract`

Value	Meaning
`false`	Program session (default)
`true`	CFP / abstract submission

Every session response includes is_abstract. Filter list/search results with filters.isAbstract in POST /v1/event/{eventId}/sessions. Create an abstract on write:

POST /v1/event/{eventId}/sessions/create
{
  "title": "Novel approach to speaker management",
  "is_abstract": true
}

Requires the Sessions 2.0 feature on the event. is_abstract cannot be changed after create.

`composition_status`

Always present on session payloads — a lightweight summary of merge/link state:

{
  "composition_status": {
    "role": "source",
    "is_linked": true,
    "is_read_only": false,
    "source_count": 0,
    "target": {
      "id": "...",
      "friendly_id": "SESS-99",
      "title": "Composite session",
      "is_abstract": false
    }
  }
}

`role`	Meaning
`standalone`	Normal editable record
`target`	Composite parent — has linked sources (`source_count > 0`)
`source`	Linked into another record — still editable via API

A linked source stays editable: field, presenter and status updates work as they do on any record, and is_read_only is always false. The key is kept for compatibility. Deleting, withdrawing, duplicating or re-composing a linked source is refused until it is unlinked in the admin UI.

Expand options

Use the existing expand array (query param on GET, request body on POST search):

`linked_sources`

By default, sessions linked as composition sources are hidden from list/search (same as the admin content list). Pass expand=linked_sources to include them.

POST /v1/event/{eventId}/sessions
{
  "expand": ["linked_sources"],
  "filters": { "isAbstract": true }
}

`composition`

Adds a full composition object with target and sources (including relationship_type):

GET /v1/event/{eventId}/sessions/{sessionId}?expand=composition

Relationship types:

Value	Meaning
`merged_session`	Program session merged into a composite
`merged_abstract`	Abstract merged into a composite abstract
`composed_into_session`	Abstract linked or composed into a program session

Use expand=composition on broad searches sparingly — it loads the full graph per row.

Session participants

Session search and get responses include legacy speakers, chairpersons, and moderators arrays and a flat participants array from the Sessions 2.0 model (Session_Participants + Session_Roles).

Use participants when you need custom program roles (Author, Panelist, etc.) or a single list of everyone on a session.
Legacy arrays remain for backwards compatibility; each legacy entry also includes participant_role when roles are configured.

Contact profile fields (photo_url, company_name, title, address_country, etc.) are hydrated on all embedded contact shapes in the event’s default language without expand. See API overview — Session participants for details.

Subsessions

Subsessions cannot be composition sources or targets. When a subsession appears in API responses, composition fields are inherited from the parent session:

GET /v1/event/{eventId}/sessions/{sessionId} with a subsession UUID returns the parent’s is_abstract, composition_status, and optional composition graph (when expand=composition).
Nested entries in parent.subsessions[] from session search receive the same inherited fields after the parent row is enriched.
Contact session endpoints (GET .../contacts/{contactId}/sessions) return is_abstract and composition_status on each linked session summary (not the full composition graph).

This matches how organizers think about program blocks: the parent session owns the composition relationship.

Contact sessions

Speaker-linked session lists include composition summary fields:

GET /v1/event/{eventId}/contacts/{contactId}/sessions
GET /v1/organization/{orgId}/contacts/{contactId}/sessions

Each session in the response includes is_abstract and composition_status. Linked composition sources are included (not filtered out). The full composition graph is not available on these lightweight endpoints — use session GET or search with expand=composition when you need source/target details.

SbQL parity

SbQL exposes separate Session and Abstract entities over the same table. REST uses is_abstract on the unified session resource. See SbQL reference.

​Sessions, abstracts & composition

​is_abstract

​composition_status

​Expand options

​linked_sources

​composition

​Session participants

​Subsessions

​Contact sessions

​SbQL parity