Types

The complete reference guide to all Clarity types.

Clarity Type System

The type system contains the following types:

Types	Notes
int	signed 128-bit integer
uint	unsigned 128-bit integer
bool	boolean value (true or false)
principal	object representing a principal (whether a contract principal or standard principal)
(buff max-len)	The buff type in Clarity is a fixed-length byte sequence. You define it with a max length like (buff 32), which represents a byte buffer of up to 32 bytes. Max buff length is 1,048,576 bytes (1 MiB).
(string-ascii max-len)	ASCII string of maximum length max-len . Max string-ascii length is 1,048,576 characters.
(string-utf8 max-len)	UTF-8 string of maximum length max-len . Max string-utf8 length is 262,144 characters.
(list max-len entry-type)	list of maximum length max-len, with entries of type entry-type
{label-0: value-type-0, label-1: value-type-1, ...}	tuple, group of data values with named fields
(optional some-type)	an option type for objects that can either be (some value) or none
(response ok-type err-type)	object used by public functions to commit their changes or abort. May be returned or used by other functions as well, however, only public functions have the commit/abort behavior.