skills

A Claude Code plugin marketplace by Ant Stanley.

Install

Register the marketplace, then install plugins individually:

/plugin marketplace add antstanley/skills
/plugin install reasoning-semiformally@skills
/plugin install spec-creator@skills
/plugin install spec-planner@skills
/plugin install jj-workspaces@skills

Plugins

Plugin	Description
reasoning-semiformally	Apply semi-formal certificate reasoning to code analysis — patch verification, fault localization, and patch equivalence.
spec-creator	Create or expand formal design specifications — numbered, layered, cross-linked markdown that defines what exists in the current branch.
spec-planner	Plan the implementation of a specification — decompose a spec into a dependency-ordered graph of reviewable task packages, each with a definition of done.
jj-workspaces	jj (jujutsu) workspaces skill for Claude Code — creates isolated workspaces for parallel work and sub-agent-driven development, and intercepts git-worktree requests in jj-managed repos.

Repo layout

.
├── .claude-plugin/marketplace.json     # marketplace manifest
├── plugins/
│   ├── reasoning-semiformally/
│   │   ├── .claude-plugin/plugin.json
│   │   ├── skills/reasoning-semiformally/
│   │   └── README.md
│   ├── spec-creator/
│   │   ├── .claude-plugin/plugin.json
│   │   ├── skills/spec-creator/
│   │   └── README.md
│   ├── spec-planner/
│   │   ├── .claude-plugin/plugin.json
│   │   ├── skills/spec-planner/
│   │   └── README.md
│   └── jj-workspaces/
│       ├── .claude-plugin/plugin.json
│       ├── skills/using-jj-workspaces/
│       └── README.md
└── docs/specs/spec.md                  # marketplace design spec

Adding a new plugin

1. Create plugins/<name>/skills/<name>/SKILL.md (with YAML frontmatter).
2. Add plugins/<name>/.claude-plugin/plugin.json and plugins/<name>/README.md.
3. Append an entry for the plugin to .claude-plugin/marketplace.json.