Usage rules and agent skills

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Corex ships eight agent skills that sync into your project via usage_rules. For live component attrs and slots, also set up Corex MCP.

Setup

Add the dependency:

mix igniter.install usage_rules

Or in mix.exs:

{:usage_rules, "~> 1.1", only: [:dev]}

Add to project/0:

def project do
  [app: :my_app, ..., usage_rules: usage_rules()]
end

defp usage_rules do
  [
    skills: [
      location: ".cursor/skills",
      package_skills: [:corex]
    ]
  ]
end

Sync and restart Cursor:

mix deps.get
mix usage_rules.sync

You get eight skills: corex-installation, corex-components, corex-design, corex-mcp, corex-api, corex-events, corex-forms, corex-navigation.

Re-run mix usage_rules.sync after upgrading Corex.

Do not also set deps: [:corex] in usage_rules config — that creates a redundant auto-generated use-corex skill.

AGENTS.md (optional)

To also write Corex rules into AGENTS.md:

defp usage_rules do
  [
    file: "AGENTS.md",
    usage_rules: [:corex, "corex:all"],
    skills: [
      location: ".cursor/skills",
      package_skills: [:corex]
    ]
  ]
end

Sub-rules cover installation, components, design, MCP, API (imperative helpers), events (on_*_change), forms, and navigation.

Search Hexdocs

mix usage_rules.search_docs "accordion set_value" -p corex

See also