SolidHaus Household Inventory Ontology
type: Ontology
description: An ontology for tracking physical items in a household, designed for use with Solid Pods and schema.org.
creator: Christopher (toph)
created: 2026-02-26
version info: 0.2.0

Sighting Event
type: Class
subclass of: FindAction
comment: An observation of an item at a specific location and time. Created when an item's barcode is scanned or its location is manually confirmed.

Audit Session
type: Class
subclass of: Action
comment: A systematic walk-through of a location to verify which items are present.

Inventory Container
type: Class
subclass of: Place
comment: A sub-location within a room that can contain items, such as a shelf, drawer, box, or cabinet.

Check-Out Event
type: Class
subclass of: CheckOutAction
comment: Records an item being taken from its storage location. The item transitions from 'checked in' to 'checked out'. Captures who took it, from where, why, and when.

Check-In Event
type: Class
subclass of: CheckInAction
comment: Records an item being returned to a storage location. The item transitions from 'checked out' to 'checked in'. May update the designated storage location if the item is being reorganized.

Short ID
type: Property
comment: A short, human-readable identifier (nanoid) used for barcodes and labels. Example: 'A3K7M2'.
domain: Thing
range: string

Barcode Format
type: Property
comment: The format of the barcode printed for this item. Values: 'qr', 'code128', 'datamatrix'.
domain: Thing
range: string

Barcode URI
type: Property
comment: The full URI encoded in the barcode, e.g. 'https://inv.toph.so/A3K7M2'.
domain: Thing
range: anyURI

Label Printed
type: Property
comment: Whether a physical label has been printed for this item.
domain: IndividualProduct
range: boolean

Label Printed At
type: Property
comment: When the label was last printed.
domain: IndividualProduct
range: dateTime

Custody State
type: Property
comment: Whether the item is currently checked in (stored) or checked out (in use, lent, etc.).
domain: IndividualProduct
range: Custody State

Checked Out Since
type: Property
comment: Timestamp when the item was last checked out of storage.
domain: IndividualProduct
range: dateTime

Checked Out Reason
type: Property
comment: Why the item was checked out of storage.
domain: IndividualProduct
range: Check-Out Reason

Checked Out From
type: Property
comment: The storage location the item was checked out from (so it can be returned there).
domain: IndividualProduct
range: Place

Checked Out To
type: Property
comment: Where or to whom the item was checked out. Can be a Place (workbench) or a Person (neighbor).
domain: IndividualProduct
range: Thing

Checked Out Note
type: Property
comment: Free-text note about the check-out, e.g. 'Lent to Max for weekend project'.
domain: IndividualProduct
range: string

Storage Tier
type: Property
comment: How accessible the storage location is. Applies to the item's designated storage or to a Place.
domain: Thing
range: Storage Tier

Storage Container
type: Property
comment: For cold-storage items: which specific container (box, bin, crate) the item is in. Important because you need to know which box to dig out.
domain: IndividualProduct
range: Thing

Storage Container Label
type: Property
comment: Human-readable label on the storage container, e.g. 'Box #3 — Electronics' or 'Blue IKEA bin — Holiday'.
domain: Thing
range: string

Last Seen At
type: Property
comment: The location where this item was most recently observed (scanned or manually confirmed).
domain: IndividualProduct
range: Place

Last Seen Timestamp
type: Property
comment: When this item was most recently observed.
domain: IndividualProduct
range: dateTime

Last Used At
type: Property
comment: When this item was last used (logged via UseAction).
domain: IndividualProduct
range: dateTime

Last Known To Be At
type: Property
comment: The most recent location where this item is known or believed to be, regardless of confidence level.
domain: IndividualProduct
range: Place

Supposed To Be At
type: Property
comment: The designated storage location for this item — where it 'belongs' or should be returned to.
domain: IndividualProduct
range: Place

Location Confidence
type: Property
comment: How confident we are about the item's current location. Values from solidhaus:ConfidenceLevel.
domain: IndividualProduct
range: Confidence Level

Location Type
type: Property
comment: The type of location in the hierarchy. Values from solidhaus:LocationType.
domain: Place
range: Location Type

Sighting Type
type: Property
comment: How the sighting was registered.
domain: Sighting Event
range: Sighting Method

Confidence
type: Property
comment: The confidence level of this specific sighting observation.
domain: Sighting Event
range: Confidence Level

Audit Location
type: Property
comment: The location being audited in this session.
domain: Audit Session
range: Place

Items Expected
type: Property
comment: Number of items expected to be found at the audit location.
domain: Audit Session
range: integer

Items Found
type: Property
comment: Number of items confirmed present during the audit.
domain: Audit Session
range: integer

Confidence Level
type: Class
comment: Enumeration of confidence levels for item location.

Confirmed
type: Confidence Level
comment: Item was directly scanned or visually confirmed at this location.

Likely
type: Confidence Level
comment: Item was seen here recently but not confirmed recently (e.g., >30 days since last scan).

Assumed
type: Confidence Level
comment: Item is assumed to be at its designated location but has not been verified.

Unknown
type: Confidence Level
comment: Item's current location is not known (e.g., >90 days since last scan).

Sighting Method
type: Class
comment: How an item sighting was registered.

Barcode Scan
type: Sighting Method
comment: Item was identified by scanning its barcode/QR code.

Manual Input
type: Sighting Method
comment: Item location was manually entered by the user.

Camera Detect
type: Sighting Method
comment: Item was detected via continuous camera scanning (future feature).

Audit Verify
type: Sighting Method
comment: Item was verified during an audit session.

Location Type
type: Class
comment: Classification of locations in the inventory hierarchy.

House
type: Location Type

Floor
type: Location Type

Room
type: Location Type

Furniture
type: Location Type
comment: A piece of furniture that contains items (desk, wardrobe, shelf unit).

Shelf
type: Location Type

Drawer
type: Location Type

Box
type: Location Type
comment: A container/box for storage.

Wall
type: Location Type
comment: Wall-mounted storage (pegboard, hooks, etc.).

Outdoor
type: Location Type
comment: Outdoor areas (garden, garage, shed).

Custody State
type: Class
comment: Whether an item is checked in (at its storage location) or checked out (removed for some purpose).

Checked In
type: Custody State
comment: Item is at its designated storage location. Put away, accounted for.

Checked Out
type: Custody State
comment: Item has been removed from storage for use, lending, repair, or other purpose.

Check-Out Reason
type: Class
comment: Why an item was taken from its storage location.

In Use
type: Check-Out Reason
comment: Item is actively being used (drill on workbench, book being read, pan on stove).

In Transit
type: Check-Out Reason
comment: Item is being moved between locations (e.g., carrying tools to another room).

Lent
type: Check-Out Reason
comment: Item has been lent to another person. Use checkedOutTo to record who.

In Repair
type: Check-Out Reason
comment: Item has been sent for repair or maintenance.

Temporary Relocation
type: Check-Out Reason
comment: Item has been temporarily moved for a project or event and should return to storage when done.

Consumed / Disposed
type: Check-Out Reason
comment: Item has been consumed, used up, or disposed of. Terminal state.

Storage Tier
type: Class
comment: How quickly and easily an item can be accessed at its storage location.

Hot / Active
type: Storage Tier
comment: Immediately accessible, grab-and-go. Examples: pegboard, desk surface, kitchen counter, tool belt hook, frequently-used drawer. Items here are used daily or near-daily.

Warm / Nearby
type: Storage Tier
comment: In the room but requires some effort to access. Examples: closed cabinet, toolbox, high shelf, under-desk drawer, closet. Items here are used weekly or occasionally.

Cold / Deep
type: Storage Tier
comment: Deep storage requiring deliberate retrieval. Examples: attic boxes, basement bins, labeled storage containers, garage overhead racks. Items here are seasonal, archival, or rarely used. For cold storage, the storageContainer and storageContainerLabel properties become especially important — you need to know which box to dig out.