The CUE standard library is always available for use through an import statement.

CUE comes with a fully featured set of built-in packages containing functions that perform a wide array of deterministic tasks. The standard library package overview links to details and examples for each package.

Some commonly used packages include:

• list: functions for manipulating and examining lists
• strings: functions for manipulating UTF-8 encoded strings
• regexp: regular expression search
• math: standard mathematical functions and constants
• encoding/base64: functions for encoding and decoding data in the RFC4648 Base64 encoding scheme
• encoding/json & encoding/yaml: functions for encoding, decoding, and validating data stored as JSON and YAML

Many of the standard library’s functions are also demonstrated in how-to guides, here on cuelang.org.