Language Overview

Craft is a declarative DSL for modeling business architectures. This reference covers all language constructs.

File Extension

Craft files use the .craft extension.

Comments

// Single-line comment

/*
  Multi-line
  comment
*/

Top-Level Constructs

A Craft file can contain any combination of these blocks:

• Actors - Define users, systems, and services
• Domains - Define business domains and bounded contexts
• Services - Define deployable services with tech stacks
• Use Cases - Model business scenarios and flows
• Architecture - Define component flows and system design
• Exposures - Define external access points

Basic Syntax Rules

Identifiers

// Valid identifiers
UserService
user_profile
API-Gateway
auth_service_v2

Rules:

• Start with letter or underscore
• Can contain letters, numbers, underscores, hyphens, dots
• Case-sensitive

Strings

"User Registration"
"Order Placed"
"Welcome to the system"

Rules:

• Double-quoted
• Cannot span multiple lines
• Use \" to escape quotes

Lists

Comma-separated, with optional trailing comma:

contexts: Authentication, Profile, Order
contexts: Authentication, Profile, Order,

Minimal Example

actors {
  user Customer
}

domain Order {
  OrderManagement
}

use_case "Place Order" {
  when Customer places order
    OrderManagement creates order
}

Language Philosophy

Declarative

Describe what the system does, not how it does it.

Natural Language

Use readable phrases like Customer places order instead of customer_place_order().

Event-Driven

First-class support for async events and domain listeners.

Domain-Focused

Center your models around business domains, not technical components.

Quick Reference

Construct	Keyword	Purpose
Actors	actors, actor	Define system actors
Domains	domains, domain	Define business domains
Services	services, service	Define deployable services
Use Cases	use_case	Model business scenarios
Architecture	arch	Define component flows
Exposures	exposure	Define API access

Next Steps

• Actors - Define users, systems, and services
• Domains - Organize business capabilities
• Services - Group domains into deployables
• Use Cases - Model business logic
• Architecture - Define system components
• Exposures - Control external access