Managing Device Assignments

An assignment relates a device to a customer, area, or asset so its telemetry carries organizational context. In DeviceChain an assignment is just a tracked relationship on the uniform entity graph — there is no separate assignment record.

Status

Available. Assignments are managed from the device detail page's Assignment tab in the console, or over the device-management GraphQL API.

Assignment organizes; it does not gate

A device authenticates with a credential; assignment only organizes its data. The two are independent:

• A device that is registered and credentialed reports telemetry immediately, even with no assignment. Its events resolve with a null anchor — they still persist and still update the device's live state; they simply aren't attributed to a customer/area/asset yet.
• Assigning the device later gives its subsequent events an anchor, so queries like "every reading for Building 7" find them.

Unassigned devices are therefore never silently dropped — a change from earlier behavior.

Every assignment is an anchor

A device may hold several assignments at once — a customer and an area and an asset. When the device reports an event, each assignment is recorded as an anchor on that event. So the same reading is queryable by every dimension: it shows up under the customer and under the area. There is no "primary" — the assignments are equal.

Concretely, each event's anchors live in a sibling event_anchors set (one row per assignment), and an anchor-filtered query ("events for area Y") matches events whose set contains that anchor. Anchors are captured at write time, so history is stable: a device that later moves areas keeps the area each old event was in when it happened.

Assign a device (console)

1. Open the device's detail page and select the Assignment tab.
2. Choose a target type (Customer / Area / Asset) and pick the target entity.
3. Click Assign. Repeat to add more assignments — the device can be assigned to several targets at once.

To unassign, click Unassign on a row. It stops anchoring the device's future events to that target; events already recorded keep their anchors.

Assign a device (GraphQL)

An assignment is a relationship edge of the reserved assigned type (a built-in tracked type, auto-provisioned per tenant on first use). Create one with the bulk mutation, addressing source and target by (type, token):

mutation {
  createEntityRelationships(requests: [{
    token: "3f1c…",            # a fresh unique edge token (e.g. a UUID)
    sourceType: "device",
    source: "sensor-001",       # device token
    targetType: "customer",     # customer | area | asset
    target: "lucidworks",       # target entity token
    relationshipType: "assigned"
  }]) { id token }
}

List a device's assignments by querying its tracked edges of the assigned type:

query {
  entityRelationships(criteria: {
    sourceType: "device", source: "sensor-001",
    relationshipType: "assigned", pageNumber: 1, pageSize: 100
  }) {
    results { id token targetType target { token } }
  }
}

Remove one with removeEntityRelationships(tokens: ["<edge token>"]). All three operations require the device:write authority (list requires device:read).

Relationship vs. assignment

Assignment is one use of the general relationship graph. The same createEntityRelationships / removeEntityRelationships mutations back group membership (the reserved untracked member type) and any custom relationship type you define. What makes a relationship an assignment that anchors events is simply that its type is tracked. See the Domain Model.