Properties

Every entity is described by its properties — named fields that hold values. Properties are what make each entity type unique: a person entity has a name and an email; an invoice has an amount and a due_date.

Properties are defined on the entity type (as child entities of type property). See Entity Types for how to set them up in the UI.

Core Concepts

Multi-valued — A single property name can hold multiple values. An entity can have several tags, phone numbers, or attachments all stored under the same property name. Enable list on the property definition to allow this.

Typed — Every property has a data type (string, number, date, file, reference, etc.) that determines the UI input and how values are stored.

Multilingual — Enable multilingual on a property definition to store a separate value per language. A language selector appears in the edit form, and the API returns language codes alongside values.

Computed — Set formula on a property definition to compute its value automatically on every save. See Formulas.

Audit trail — All property values carry creation metadata (timestamp and user), making it traceable who set what and when.

System properties — Properties beginning with _ (_id, _type, _parent, _owner, etc.) are managed by Entu and control identity, hierarchy, and access rights.

INFO

Custom property names cannot start with _. That prefix is reserved for system properties. Property names must also consist only of letters, digits, and underscores (A–Z, a–z, 0–9, _). Hyphens, dots, spaces, and other characters are not allowed and will be rejected.

Property Types

Type	Input	Notes
string	Single-line text	Default text input. If set is defined on the property definition, renders as a dropdown.
text	Multi-line textarea	Auto-resizes between 3–15 rows. Enable markdown to allow rich formatting.
number	Number input	Locale-formatted. Use decimals on the property definition to control precision.
boolean	Toggle switch	Stores true or false.
date	Date picker	Stores date only — no time component.
datetime	Date + time picker	Stores a full timestamp.
file	File upload	Stores a file attachment. See Files for the upload process.
reference	Entity selector	Links to another entity. Use reference_query on the definition to filter selectable options.
counter	Auto-generated code	Read-only in the UI. Shows a generate button when empty; displays the value once assigned. Use for invoice numbers, project codes.

Multi-Value Properties

When a property definition has list: true, the entity can hold multiple values for that property. In the edit form, extra empty inputs appear automatically as the user fills them in.

Via the API, each value is a separate property object — add values by POSTing, remove specific values by DELETEing their _id.

Multilingual Properties

When multilingual: true is set on a property definition, each value carries a language code. The edit form shows a language selector next to each input.

Values for different languages are stored as separate property objects, each carrying a language code. See API → Properties for the API format.

File Properties

File properties let entities store attachments, documents, images, and other binary data. Files are stored in object storage (S3-compatible) and accessed via signed, time-limited URLs.

To enable file uploads on an entity type, add a property definition with type: file.

TIP

If a file property named photo exists on an entity, the Entu UI will use it as the entity's thumbnail.

Computed Properties

Set formula on a property definition to compute its value automatically from other data — the entity's own properties, child entities, or entities that reference it. Computed properties are recalculated on every save and cannot be edited manually.

TIP

Use computed properties for totals, counts, and aggregations so derived data always stays in sync with the source.

See Formulas for the full syntax reference.

Properties Used by Entu UI

The following property names have special meaning in the UI. You can define them on any entity type and the system will use them automatically.

Property	Type	Behaviour
name	string	Used as the entity's display title throughout the UI — in lists, breadcrumbs, search results, and as the page heading. If absent, the entity _id is shown instead.
photo	file	The first value is used as the entity's thumbnail image in lists and the entity page header. The system also exposes it as _thumbnail — a ready-to-use signed download URL.

System Properties

System properties begin with _ and control entity behavior, access rights, and metadata. Custom property names cannot begin with _.

Property	Description
_id	Unique entity identifier. Read-only, auto-generated.
_type	Reference to the entity type definition. Required on every entity.
_parent	Reference to a parent entity. An entity can have multiple _parent values.
_sharing	Visibility level: private (default), domain, or public.
_inheritrights	When true, the entity inherits access rights from its parent.
_owner	Full control — view, edit, delete, manage rights, create children.
_editor	Can view and edit all properties except rights.
_expander	Can view and create child entities.
_viewer	Read-only access.
_noaccess	Explicitly denied all access. Overrides inherited rights from parents.
_created	Creation timestamp and user. Read-only, auto-generated.
_deleted	Deletion timestamp and user. Set when the entity is deleted.
_thumbnail	Signed, time-limited download URL generated from the entity's photo property. Read-only, auto-generated.

Deletion

Properties are never physically removed from the database. When a property value is deleted:

• It is marked with deleted.at (timestamp) and deleted.by (the user who performed the deletion).
• It is automatically excluded from all API responses and the UI.
• The deletion record is permanent — you always know what was removed, when, and by whom.

INFO

Because property values are only soft-deleted, the full history of who set or removed every value is always preserved, even after the parent entity is gone.