noDDDe

noDDDe is a TypeScript framework for building business applications using Domain-Driven Design (DDD), Command Query Responsibility Segregation (CQRS), and Event Sourcing patterns.

It provides a declarative, type-safe way to express domain aggregates using the functional Decider pattern — no base classes, no decorators, just typed objects and pure functions.

Key Principles

• Pure functions over class hierarchies — Aggregates are objects with handler maps, not classes with methods
• Type safety via mapped types — DefineCommands and DefineEvents build discriminated unions from simple payload maps
• The Decider pattern — initialState + commands (decide) + apply (evolve)
• Infrastructure injection — Dependencies are function parameters, not imports; testable by default

Choose Your Path

New to DDD / CQRS / Event Sourcing?

Start with the foundational concepts:

• Messaging — How typed messages drive the architecture
• The Decider Pattern — The functional foundation
• CQRS — Separating reads from writes
• Event Sourcing — Storing events, not state

Want to build something?

Jump into the hands-on guides:

• Installation — Get @noddde/core installed
• Quick Start — Build a bank account aggregate step by step

Know the patterns?

Go directly to the reference:

• Defining Aggregates — The defineAggregate function
• Defining Commands — The DefineCommands utility type
• Defining Events — The DefineEvents utility type
• Domain Configuration — Wiring everything together

Understand the design

Learn why noddde is built the way it is:

• Why the Decider Pattern? — Pure functions vs. OOP
• Why DefineCommands/Events? — Mapped types vs. enums
• Why Injectable Infrastructure? — Testability by design