DDD & Design Patterns Skills for Agentic Development

An agent skills collection for Domain-Driven Design, software design patterns, research, and a strict test-driven developer lifecycle. The repository ships Claude Code marketplace packaging today, and the skill instructions are written so other agent harnesses such as Codex, Copilot, and Gemini can adapt the same workflows through explicit tool mappings.

Installation & Getting Started

Claude Code Marketplace

Claude Code uses the .claude-plugin/ directories as its marketplace adapter.

1. Add the marketplace from GitHub: run /plugin marketplace add davidsouther/domain-driven-design.
   • You can also run /plugin to open the interactive browser and add it from the Marketplaces tab.
2. Install the skills with /plugin install @ailly — install general, developer, patterns, and research (domain is optional). Browse and toggle them anytime from the Installed tab of /plugin.

Updating: Ailly does not auto-update when new versions are pushed. Run /plugin marketplace update ailly to pull the latest skills. Local development: To work from a local clone instead, run /plugin marketplace add .

Codex Plugin Mirrors

Codex uses the */.codex-plugin/plugin.json manifests as its plugin adapter. This repository includes Codex mirrors for the skill plugins: developer, domain, general, patterns, and research.

Repo-local Codex marketplace metadata lives at .agents/plugins/marketplace.json. Its entries point back to the plugin folders in this checkout, where each .codex-plugin/plugin.json lives. The characters package remains Claude Code-specific because it is an output-style package rather than a portable skill plugin.

Pi Package

On pi, Ailly’s workflow is implemented as tools rather than prose. The skills describe the process; the extensions in .pi/extensions/ carry out the mechanical parts — spawning subagents, naming folders, checking that promised files exist — so those steps don’t depend on a model following instructions correctly.

Install with pi install git:davidsouther/domain-driven-design from any project. To work on this repo itself, .pi/settings.json already self-references the package; approve the project (pi -a) and pi discovers the five skill plugins, the /ailly* prompt templates in prompts/, and the extensions. The root package.json’s pi manifest (pi.skills, pi.prompts, pi.extensions) contains nothing specific to this checkout’s location.

Pi has no built-in Task tool, so subagent dispatch is a separate pi subprocess per call:

• ailly_subagent — runs one Ailly phase or ability in an isolated subprocess that reads exactly one reference file.
• research_dispatch — runs one or more research skills, in parallel when combined; computes the dated notes folder and checks each skill’s findings file landed on disk.