Reference

Value Types Reference

Variable values are TOML values that rototo validates and returns as JSON-like values during resolution.

Variables declare either a primitive type or a JSON schema. They must not declare both.

Primitive Types

Primitive type variables use:

[variable]
type = "int"

Supported primitive types:

bool
int
number
string
list

`bool`

TOML boolean.

[variable.values]
enabled = true
disabled = false

`int`

TOML integer.

[variable.values]
small = 500
large = 2000

`number`

TOML integer or floating point number.

[variable.values]
low = 0.1
standard = 1

`string`

TOML string.

[variable.values]
control = "Welcome back."
premium = "Welcome back, premium member."

`list`

TOML array.

[variable.values]
default = ["card", "bank_transfer"]

The primitive list type validates that the value is an array. It does not declare element types. Use a JSON Schema variable when element shape matters.

Structured Values

Structured values should use schema, not primitive type.

[variable]
schema = "../schemas/llm-config.schema.json"

Each configured value is validated against the referenced JSON Schema during lint.

Inline object values:

[variable.values.enterprise]
model = "gpt-5"
gateway = "openai"
max_output_tokens = 5000
temperature = 0.2

External object value:

[value]
model = "gpt-5"
gateway = "openai"
max_output_tokens = 5000
temperature = 0.2

TOML to JSON

Resolution output is JSON. TOML values are converted to JSON-compatible values:

TOML booleans become JSON booleans.
TOML integers and floats become JSON numbers.
TOML strings become JSON strings.
TOML arrays become JSON arrays.
TOML tables become JSON objects.

Choosing `type` Or `schema`

Use primitive type for small scalar or list decisions.

Use schema when the value is an object, when a list needs element validation, or when application code expects a precise structured contract.

Validation

Value validation happens during lint:

primitive variables check every value against type;
schema-backed variables check every value against the JSON Schema;
external value files are loaded before validation;
custom lint_value(value) runs after values have been expanded.

Value Types Reference

Primitive Types

bool

int

number

string

list