Designing with Capabilities

This page contains links to the slides and code from my talk “Designing with Capabilities”.

Here’s the blurb for the talk:

We all want to produce modular and robust code that is easy to test and refactor, and we have design principles such as SOLID that help us do that.

In this talk I’ll look at a very different approach to design using “capabilities” and the principle of least authority. I’ll show how using these design techniques throughout your core domain (and not just at your API boundary) also leads to well-designed and modular code.

I’ll demonstrate how to design and use a capability based approach, how capabilities can be quickly combined and restricted easily, and how capabilities are a natural fit with a REST API that uses HATEAOS.

This talk is based on my blog posts on this topic:

• A functional approach to authorization
• Constraining capabilities based on identity and role
• Using types as access tokens

Also related are the talk and posts on designing Enterprise Tic-Tac-Toe:

• Enterprise Tic-Tac-Toe
• Enterprise Tic-Tac-Toe Part 2, In which I throw away the previous design
• Video and slides for my “Enterprise Tic-Tac-Toe” talk

Video from NDC London, Jan 15, 2016 (Click image to view video)

The code used in the demos is available on github.

Slides from NDC London, Jan 15, 2016

These slides from DDD Europe, Feb 3, 2017 are more DDD focused