Event Stream

The signageOS Event Stream delivers real-time domain and telemetry events to your webhook endpoints as they occur on the platform.

Set up an exporter

To start receiving these events, create an exporter that subscribes to the event types you need:

• Set up in Box (UI)
• Set up via REST API

For the concepts, see Introduction to Event Stream Distributor.

Webhook Delivery Format

Each event is delivered as an HTTP POST with a JSON body containing exactly five fields:

{
  "id": "0197f2a4-3a5e-7b1c-9d2f-8c4e6a1b3d5f",
  "kind": "domain",
  "type": "Device.Connect.DeviceConnected",
  "dispatchedAt": "2026-01-01T00:00:00.000Z",
  "payload": { ... }
}

Field	Type	Description
id	string	Unique identifier of the event instance, generated when the event is emitted. It stays the same across repeated deliveries of the same event — use it to deduplicate redeliveries.
kind	"domain" | "telemetry"	Category of the event
type	string	Fully-qualified event type identifier
dispatchedAt	string	ISO 8601 timestamp of when the event happened on the platform. It stays the same across repeated deliveries of the same event. Deliveries can arrive out of order — buffer them for a short window and apply them in dispatchedAt order, never in arrival order or by X-SOS-Timestamp.
payload	object	Event-specific data (see individual event pages)

Webhook Headers

Every delivery includes the following HTTP headers:

Header	Description	Presence
X-SOS-Sequence-Number	Stringified integer — monotonically increasing delivery sequence	Domain events only
X-SOS-Exporter-Config-Uid	UID of the exporter configuration that produced this delivery	All events
X-SOS-Timestamp	Unix timestamp in seconds of the delivery attempt. A retried delivery is signed with a fresh value, so you can enforce a tight replay window when verifying the signature. Never use it to order or deduplicate events — use the body dispatchedAt and id for that	All events
X-SOS-Signature	Base64 HMAC-SHA256, prefixed with v1=, over {METHOD}{url}{timestamp}{body} (uppercased HTTP method, concatenated, no separators) using your configured webhook secret	All events

Event Catalogue

Alert

4 event types

Device

2 event types

Device / Provisioning Recipe

4 event types

Device / System Log

12 event types

Device / Telemetry

1 event type

Device / Verification

2 event types