Schema reference

Start with a type, then chain checks and transformations. Each method returns a new schema, so you can reuse a base schema without changing it.

final email = string().email();
final account = object({'email': email});

New to Acanthis? Follow the quick start for a complete example.

StringsValidate text, check formats, and transform string values.Numbers, booleans, and datesChoose a primitive schema and add the constraints your data needs.ObjectsValidate named fields, control unknown keys, and compose reusable object schemas.Lists and tuplesValidate repeated values with lists or fixed positions with tuples.Nullable valuesAllow null explicitly and distinguish it from an absent object field.Instances and classesValidate existing Dart instances and describe class fields.Literals and unionsMatch exact values or accept one of several schema shapes.Custom validationAdd synchronous or asynchronous rules when built-in checks are not enough.Transformations and defaultsConvert input values, chain schemas, and provide recovery defaults.Mock dataGenerate sample input and choose between legacy mocking and bounded seeded generation.

Find a specific type or operation

Type or operation	Reference
String	View guide
String Formats	View guide
Emails	View guide
Numeric values	View guide
Booleans	View guide
Dates	View guide
Nullables	View guide
Objects	View guide
extend()	View guide
merge()	View guide
pick()	View guide
omit()	View guide
partial()	View guide
Recursive Objects	View guide
Lists	View guide
Instances	View guide
Differences to object()	View guide
Cross-field validation with refs	View guide
Class Schemas	View guide
Tuples	View guide
variadic()	View guide
Literals	View guide
Union	View guide
variant()	View guide
Refinements	View guide
refine()	View guide
refineAsync()	View guide
Pipes	View guide
Default Values	View guide
Template Literals	View guide
Mocking schemas	View guide
Type Coercion	View guide
coerce() and Unions	View guide
Seeded test data	View guide