Schema Data Types

The Internet Object schema type system — base types, shortcuts, and TypeDefs.

A schema constrains each member to a type. The type system is small by design: a handful of base types, plus a closed set of shortcuts — names that stand for a base type with preset constraints baked in. Every type is configured through its TypeDef, the fixed set of options it accepts.

Base types

Type	Validates	Reference
string	Text	String Types
number	An IEEE-754 number	Numeric Types
bigint	An arbitrary-precision integer (123n)	BigInt
decimal	A fixed-precision decimal (123.45m)	Decimal
bool	true / false	Bool
date, time, datetime	Temporal values (d'…', t'…', dt'…')	Date and Time
binary	Byte data, written as base64 (b'…')	Binary
object	A structured shape (a SchemaDef)	Object (SchemaDef)
array	An ordered list of values	Array
any	Any value; the default when no type is given	Any

A member written without a type defaults to any, so name, age declares two any members.

date, time, and datetime are their own types, not subtypes of string. Earlier drafts described them as string-derived; they are temporal types with their own literal values. See Date and Time.

Shortcuts

A shortcut is a built-in name equal to a base type plus preset constraints. It is not a new type — it is a convenient, validated configuration of a base type. A conformant validator MUST recognize every shortcut name.

Base	Shortcuts	Each shortcut is…
string	email, url	string with a built-in pattern
number	int, uint, int8, int16, int32, uint8 (byte), uint16, uint32	number restricted to whole values in a fixed range

See Numeric Types for the full numeric family and ranges, and String Types for email and url.

Reserved. int64, uint64, float32, and float64 are reserved for future use and are not yet validated by the reference implementation.

TypeDef and MemberDef

Each type defines a TypeDef — the exact set of options it accepts (for example, string accepts pattern, minLen, maxLen; number accepts min, max, multipleOf). Supplying a type together with chosen options produces a MemberDef, the definition of a single member:

name:  { string, minLen: 1, maxLen: 100 },   # a string MemberDef
score: { int, min: 0, max: 100 }             # a number MemberDef
---
~ John, 85

The first value in a MemberDef is the type; the second is the default; the third is choices. Remaining options are written as key: value pairs. An option a type does not define is rejected. Each type page lists its TypeDef in full.

See Also

• Overview — how schemas are built

• TypeDef — the option-contract model

• MemberDef — types, constraints, optional/nullable/default

• Numeric Types · String Types · Date and Time