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Real-Time Updates

Overview​

OpenRegister provides live data synchronization to connected clients via Server-Sent Events (SSE) as the primary transport, with Nextcloud notify_push as a complementary channel and graceful fallback to polling. All real-time channels are authorization-aware — users only receive events for objects their RBAC permissions allow them to see. Subscriptions are topic-based at the register, schema, or individual object level.

Server-Sent Events (SSE)​

SSE is the primary real-time transport. Clients open a persistent HTTP connection and receive a stream of events:

GET /api/realtime/subscribe?topic=register/meldingen-register/schema/meldingen

Topics​

Topic PatternDescription
register/{slug}All events for all schemas in a register
register/{slug}/schema/{slug}All events for a specific schema
object/{uuid}Events for a single object
organisation/{uuid}All events for an organisation (multi-tenant)

Multiple topics can be subscribed in one connection:

GET /api/realtime/subscribe?topic[]=register/meldingen&topic[]=register/besluiten

Event Format​

Events are delivered in CloudEvents v1.0 format as SSE data: lines:

event: object.created
data: {"specversion":"1.0","type":"nl.conduction.openregister.object.created","source":"...","id":"evt-123","time":"2026-03-21T12:00:00Z","data":{"uuid":"...","schema":"meldingen","register":"meldingen-register","object":{...}}}

event: object.updated
data: {"specversion":"1.0","type":"nl.conduction.openregister.object.updated",...,"data":{"uuid":"...","changed":{"status":{"old":"nieuw","new":"in_behandeling"}}}}

RBAC Filtering​

Before each event is sent to a subscriber, the SSE service checks:

  1. Schema-level RBAC: does the subscriber have read permission for the event's schema?
  2. Row-level RBAC: do the object's field values satisfy the subscriber's conditional rules?
  3. Property-level RBAC: unauthorized fields are stripped from the event payload

This ensures users only receive events for data they are authorized to see, even in multi-tenant deployments.

Reconnection with Event Replay​

Clients that disconnect and reconnect can request missed events:

GET /api/realtime/subscribe?topic=...&lastEventId=evt-099

The SSE service replays events since lastEventId from an in-memory ring buffer (configurable size, default 1000 events). Events older than the buffer are not replayed — clients should poll for a full resync.

Authentication​

SSE connections require authentication:

  • Session auth: cookie included in the EventSource request
  • Bearer token: ?token=<api-token> URL parameter (for clients that cannot set headers on EventSource)
  • OAuth2: standard Bearer token in Authorization header

GraphQL Subscriptions​

Real-time events are also available via GraphQL subscriptions over SSE:

GET /api/graphql/subscriptions?query=subscription { meldingenEvents(filter:{status:"nieuw"}) { _uuid titel status } }

GraphQL subscriptions support inline filtering (only events matching the filter are delivered) and field selection (only requested fields are in the payload).

Nextcloud notify_push Integration​

For Nextcloud desktop and mobile clients, OpenRegister publishes notifications via notify_push:

  • Object changes trigger a push notification to connected Nextcloud clients
  • The client then polls the REST API for the actual updated data
  • Enables notification on mobile without a persistent SSE connection

Polling Fallback​

When SSE or notify_push is unavailable, clients can poll:

GET /api/objects/{register}/{schema}?_updatedSince=2026-03-21T12:00:00Z&_limit=50

The _updatedSince parameter returns only objects updated after the given timestamp. Combined with the _updated field on each object, clients can implement efficient incremental polling.

API​

GET /api/realtime/subscribe              SSE subscription endpoint
GET /api/realtime/topics                 List available topics
GET /api/realtime/status                 Connection statistics

Standards​

StandardRole
Server-Sent Events (W3C)Primary real-time transport
CloudEvents v1.0Event payload format
GraphQL SubscriptionsReal-time GraphQL queries
Nextcloud notify_pushMobile/desktop push notification channel