Variables

Value variables — reusable values referenced with @.

A value variable is a reusable value defined in the header with an @-prefixed key and used anywhere a value is expected by writing @name. Variables reduce repetition, shrink payloads, and let you keep sensitive values in one place.

@ is for values. For reusable schemas and types, use $ references — see Schema References.

Defining and using

~ @active: T
~ $schema: { name: string, isActive: bool }
---
~ John, @active
~ Jane, @active

In schema constraints

A variable can supply a constraint value, such as a choices list:

~ @r: red
~ @g: green
~ @b: blue
~ $schema: { name: string, color: { string, choices: [@r, @g, @b] } }
---
~ John, red

Use cases

Reduce size and repetition

Define a value once and reference it many times:

~ @co: 'ACME Corporation'
~ $schema: { name: string, employer: string }
---
~ John, @co
~ Jane, @co

Keep sensitive values together

Variables let you isolate secrets/keys in the header instead of scattering them through the data:

~ @key: 'sk_live_8f3a9c2b'
~ $schema: { account: string, apiKey: string }
---
~ acct_001, @key

See Also

• Definitions · Schema References