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The Leo Programming Language

Welcome to the Leo programming language. Leo is a statically-typed programming language built for writing private applications. Leo is a high-level programming language that compiles down to low-level Aleo Instructions.


The Leo language is currently in active development. Please monitor the repository on GitHub for possibly breaking changes.

Installing Leo

Proceed to Installation for information on how to install Leo.

Getting Started

Check out the Hello Leo tutorial for a brief walk-through of Leo and the Leo CLI.

Language Guide

To learn about Leo's supported types, start with Data Types and Values.

To learn the core concepts and syntax of Leo, start with the Layout of a Leo Program.

To view the full list of supported operators in Leo, see Operators.

For a quick reference of Leo syntax, see the Leo Cheat Sheet.

Formal Language Documentation

A formal ABNF grammar specification for the syntax of Leo can be viewed here.

Command Line Interface Documentation

The Leo CLI provides a suite of commands to make programming in Leo easy.

Additional Material

Install Leo for your favorite code editor.

For additional developer resources such as examples and community projects, see Developer Resources.

Is your Leo code formatted correctly? Check out the Style Guide and Common Patterns for the official guidelines.

Found a bug? Have an idea for a feature? File an issue on the Leo GitHub.

See the Contributing Guide for more information.