Property

A property is a single data point on an entity. Its type drives the UI component.

Purpose

Describe data semantics (meaning), not pixel layout. The runtime infers the right component.

Types

Class	type	Key params
Number	number	unit, min, max, max_rate, deadband, step
Boolean	boolean	writable
Enum	enum	options, writable
String	string	max_length
Location	location	lat, lng (map widget)

Signature

Number(unit=None, min=None, max=None, max_rate=None, deadband=None, step=None,
       writable=False, view=None, label=None, configurable=None, automation=None)
Boolean(writable=False, view=None, label=None, configurable=None, automation=None)
Enum(options=[], writable=False, view=None, label=None, configurable=None, automation=None)
String(max_length=None, writable=False, view=None, label=None, configurable=None, automation=None)
Location(lat=None, lng=None)

Common metadata

• label — human-readable display name; frontend auto title-cases the key otherwise (fill_valve → "Fill Valve")
• configurable={"warning": True} — user can set a warning threshold on this property
• automation={"allow_set": True} — automation rules may set this property (developer-controlled boundary: manual write ≠ automation write)

Minimal example

Number(unit="°C")

Complete example

Number(
    unit="bar",
    min=0,
    max=10,
    view="slider",       # presentation hint
    label="Pressure",    # human-readable name
    writable=True,
    max_rate=2,          # emit ≤ 2 updates/sec
    deadband=0.1,        # skip changes < 0.1
    configurable={"warning": True},
    automation={"allow_set": True},
)

Constraints

• max_rate and deadband only apply to Number
• view must be one of: metric, gauge, trend, status, switch, select, text, slider, progress, alarm, input, badge, image, table, log, map
• deadband/max_rate reduce runtime→frontend emission only, never upstream ingestion

Common mistakes

• Setting min/max but expecting them to clamp values — they only inform the widget
• Using writable=True without an on_write handler → value updates optimistically
• Forgetting automation={"allow_set": True} on writable properties that automation rules should control

Generated schema

{
  "type": "number",
  "unit": "bar",
  "min": 0,
  "max": 10,
  "writable": true,
  "label": "Pressure",
  "presentation": { "preferred": "slider" },
  "configurable": { "warning": true },
  "automation": { "allow_set": true }
}