Optimum Cursor rules

Cursor rules suitable for development using Elixir and Phoenix.

🚨 CRITICAL: Fix Cursor .mdc Editor Bug First

Before using these rules, you must fix a critical bug in Cursor's .mdc file handling:

Cursor's custom .mdc editor is severely buggy and causes multiple issues:

• Cursor jumps to description field during editing
• Auto-save disrupts workflow and causes focus issues
• Agent thinks it's editing files but changes don't persist to filesystem
• Files may appear empty when they contain content

Fix Required

Add this to your Cursor settings to disable the custom .mdc editor:

"workbench.editorAssociations": {
  "*.mdc": "default"
}

How to apply:

1. Open Cursor Settings (Cmd/Ctrl + ,)
2. Search for "editorAssociations"
3. Add the mapping above
4. Restart Cursor if needed

This treats .mdc files as regular markdown, eliminating all editing bugs.

Setup

Add the repo as a git submodule to your Phoenix app.

git submodule add https://github.com/optimumBA/cursor_rules .cursor/rules

Rules should automatically be applied by Cursor.
They can live side-by-side with your existing rules.

Updating

To update the Cursor rules to the latest version:

git submodule foreach "git checkout main && git pull"

This ensures you get the latest improvements and bug fixes to the rules.