Documentation

Welcome to the function-hcl documentation.

function-hcl is a Crossplane composition function that lets you write compositions using an HCL-based DSL with a familiar feel for Terraform users.

Where to start

  • New to function-hcl? Start with Getting Started to install and write your first composition.
  • Learning the DSL? The Language Guide walks through every construct with examples.
  • Looking for practical advice? Tips & Pitfalls covers best practices and common gotchas.
  • Coming from Terraform? See For Terraform Users for a mapping of concepts.
  • Need specifics? The Reference has the complete DSL specification.

Getting Started

Install function-hcl and write your first composition.

Concepts

Core concepts behind function-hcl.

Language Guide

A tutorial-style guide to every construct in the function-hcl DSL.

Tips and Pitfalls

Best practices, common gotchas, and practical advice for writing function-hcl compositions.

Reference

Complete reference documentation for the function-hcl DSL.

For Terraform Users

A guide for people coming from Terraform to function-hcl.

Last modified March 7, 2026: docs (235cb74)