pkl

pkl [command] [options] [file]

pkl is a programmable configuration language developed by Apple. It evaluates .pkl files and generates output in multiple formats including JSON, YAML, XML, and property lists, combining the readability of static configuration with the power of a programming language.Pkl provides type safety, validation, and code reuse through classes and modules, catching configuration errors at evaluation time rather than at deployment. The REPL mode allows interactive exploration and testing of configuration expressions.

eval FILE

Evaluate configuration.

Validate syntax.

Start interactive mode.

Output format.

Display help.

Pkl files can import modules from the network, which may have security implications. The language requires a JVM-based runtime or native binaries for evaluation.

Pkl was created by Apple and open-sourced in February 2024 as a type-safe, programmable configuration language.

jsonnet(1), dhall(1)