Litmus Edge 4.4.x - DeviceHub: Subscriptions

Subscribe Browse Task Changed

POST {{edgeUrl}}/devicehub/v2

Subscribe Browse Task Changed

WebSocket subscription: run this over the GraphQL-over-WebSocket protocol at wss://{{edgeHost}}/devicehub/v2 (graphql-transport-ws). In Postman, create a WebSocket request and send the subscription as a subscribe message payload -- a plain HTTP POST will not stream events.

WebSocket subscription. Convert to a Postman WebSocket request after import (URL: wss://.../devicehub/v2).

Endpoint

POST {{edgeUrl}}/devicehub/v2
Content-Type: application/json

Authentication

HTTP Basic Auth. Username is your API token, password is empty. The same token is valid across /devicehub/v2, /analytics/v2, /cc, /opcua, and the other LE services.

Request body (GraphQL)

subscription BrowseTaskChanged {
    BrowseTaskChanged {
        ID DeviceID DisplayName Status StatusDescription FoldersCount ItemsCount SizeOnDiskBytes
    }
}

Errors

GraphQL endpoints return 200 OK even on logical errors. Inspect the errors array in the response body:

{ "errors": [ { "message": "...", "path": ["..."], "extensions": { "code": "..." } } ] }

A non-200 HTTP response means DeviceHub itself is unreachable. See Dashboard > DeviceHub Status.

TLS note: edge devices use a self-signed certificate by default. Either install the device CA in your client trust store or disable certificate verification when calling this endpoint directly.

Request Body

GraphQL Query

subscription BrowseTaskChanged {
    BrowseTaskChanged {
        ID DeviceID DisplayName Status StatusDescription FoldersCount ItemsCount SizeOnDiskBytes
    }
}

Subscribe Device State Changed

POST {{edgeUrl}}/devicehub/v2

Subscribe Device State Changed

WebSocket subscription: run this over the GraphQL-over-WebSocket protocol at wss://{{edgeHost}}/devicehub/v2 (graphql-transport-ws). In Postman, create a WebSocket request and send the subscription as a subscribe message payload -- a plain HTTP POST will not stream events.

WebSocket subscription. State enum: StartedConnected | StartedDisconnected | StartedUnknown | Stopped | Created | Starting | Stopping | Updated | Deleted | WDActivated | WDStopping | WDStarting.

Endpoint

POST {{edgeUrl}}/devicehub/v2
Content-Type: application/json

Authentication

HTTP Basic Auth. Username is your API token, password is empty. The same token is valid across /devicehub/v2, /analytics/v2, /cc, /opcua, and the other LE services.

Request body (GraphQL)

subscription DeviceStateChanged {
    DeviceStateChanged {
        ID State
    }
}

Errors

GraphQL endpoints return 200 OK even on logical errors. Inspect the errors array in the response body:

{ "errors": [ { "message": "...", "path": ["..."], "extensions": { "code": "..." } } ] }

A non-200 HTTP response means DeviceHub itself is unreachable. See Dashboard > DeviceHub Status.

TLS note: edge devices use a self-signed certificate by default. Either install the device CA in your client trust store or disable certificate verification when calling this endpoint directly.

Request Body

GraphQL Query

subscription DeviceStateChanged {
    DeviceStateChanged {
        ID State
    }
}

Subscribe Search Task Changed

POST {{edgeUrl}}/devicehub/v2

Subscribe Search Task Changed

WebSocket subscription: run this over the GraphQL-over-WebSocket protocol at wss://{{edgeHost}}/devicehub/v2 (graphql-transport-ws). In Postman, create a WebSocket request and send the subscription as a subscribe message payload -- a plain HTTP POST will not stream events.

WebSocket subscription. Reports search task progress in real time.

Endpoint

POST {{edgeUrl}}/devicehub/v2
Content-Type: application/json

Authentication

HTTP Basic Auth. Username is your API token, password is empty. The same token is valid across /devicehub/v2, /analytics/v2, /cc, /opcua, and the other LE services.

Request body (GraphQL)

subscription SearchTaskChanged {
    SearchTaskChanged {
        ID Status Progress SearchedItemsCount
    }
}

Errors

GraphQL endpoints return 200 OK even on logical errors. Inspect the errors array in the response body:

{ "errors": [ { "message": "...", "path": ["..."], "extensions": { "code": "..." } } ] }

A non-200 HTTP response means DeviceHub itself is unreachable. See Dashboard > DeviceHub Status.

TLS note: edge devices use a self-signed certificate by default. Either install the device CA in your client trust store or disable certificate verification when calling this endpoint directly.

Request Body

GraphQL Query

subscription SearchTaskChanged {
    SearchTaskChanged {
        ID Status Progress SearchedItemsCount
    }
}