References
Usefule references
Keyword Reference
Keywords are context-sensitive (section 2.4): each has special meaning only in the context listed below and is an ordinary identifier elsewhere.
| Keyword | Context | Description |
|---|---|---|
skill |
File-level | Declares the skill scope and version for the file |
use |
File-level | Imports types from another skill |
as |
After use import; after the type in a union tag |
Aliases an imported type to avoid collisions; names a union’s generated enum |
type |
Top-level | Defines a basic constrained type |
enum |
Top-level | Defines an enumeration type |
object |
Top-level | Defines a complex object type |
union |
Top-level | Defines a discriminated union type |
tag |
Inside union |
Declares the discriminant property |
error |
Top-level | Declares an error type with optional data properties |
service |
Top-level | Defines a named or anonymous service |
func |
Inside service |
Defines a callable function |
notify |
Inside service |
Defines a notification/event |
concept |
Top-level | Defines an ontological concept |
is |
Inside concept |
Declares conformance to another concept |
within |
Inside concept |
Declares that the concept exists within the domain of another concept |
property |
Inside concept |
Declares a static attribute |
command |
Inside concept |
Declares an abstract operation |
state |
Inside concept |
Declares a dynamic runtime condition |
event |
Inside concept |
Declares an observable occurrence |
since |
Before any definition | Marks version introduction |
until |
After since |
Marks version removal |
optional |
Parameter position, before the type | Marks a function/notification parameter as omittable by the caller |
view |
Top-level | Defines a projection (property subset) of an object |
of |
After the view name |
Introduces the view’s target object |
Built-in Type Quick Reference
Scalars: bool, int, float, string, guid, time, data, symbol, symbolpath, strid, value
Return-only: void
Parameter-only: select (property-selection parameter, wire form is a string array)
Containers: T[] (array), T[#] (indexed array), T{} (map), T{KeyType} (typed-key map); map shapes can be named via type declarations (named map types, section 7.1)
Nullability: T?
Annotation Quick Reference
| Annotation | Level | Applies to | Description |
|---|---|---|---|
@readonly |
Property, parameter | Any | Cannot be set via API |
@sparse |
Definition | object only |
Default-value fields omitted in transmission |
@sparse |
Property | Object-typed only | Field’s type behaves as sparse in this context |
@global |
Definition | error only |
Error is implicit on every function in the skill |
@localizable |
Property, known-key entry, parameter | string/strid-rooted only | Value is translatable by the translation system |
Last modified September 25, 2026