Skip to content
Chelis docs

Chelis developer book

Chelis is a functional programming language for AI research. Surf is the readable syntax for humans. Deep is the canonical s-expression syntax for machines and the compiler.

This book is the practical starting point for downstream users and shell authors. It covers local setup, the first program loop, CLI validation, the style gate, Reef package basics, examples, and the map from user docs to the authoritative specs.

If you are modifying Chelis itself, use the repository AGENTS.md and the shared agent-skills/ workflows instead. This book is for using Chelis and authoring packages on top of it.

What you should read first

Section titled “What you should read first”

A small Surf program

Section titled “A small Surf program”
def square(x: tensor[f32]) -> tensor[f32] = mul(x, x)

This is a complete, compiler-validated example. In this book:

  • chelis-surf and chelis-deep fences are full programs and are validated in CI.
  • chelis-surf-fragment and chelis-deep-fragment fences are partial snippets used to teach one construct in isolation.