Give Cursor useful project rules

Save a short project rule and verify it applies to a real task.

Before you start

• A project open in Cursor and permission to add project guidance.
• Two or three stable conventions confirmed in the existing code or README.

Want to do it yourself?

Difficulty

4 out of 10

Estimated completion time

25–45 minutes

Skills you’ll need: Edit a small .mdc rule, select its scope, and check that a fresh task uses the intended guidance.

I’ll do it myselfI’d rather get help

How this helps your brand

Keep repeated website changes consistent with your established components and content conventions. A short, tested project rule reduces the need to explain the same requirements in every new Cursor conversation.

1. 1

   Step 1: Choose conventions worth repeating

   Pick guidance that future changes should follow: reuse an existing button component, keep business copy approved, or run the project’s established checks.

   Name actual files and commands from this project. Avoid long wish lists or rules that contradict the codebase.

2. 2

   Step 2: Create a project rule

   Create a rule under .cursor/rules using the .mdc extension. Cursor’s rule editor lets you choose when it applies.

   For a short convention needed on every task, choose Always Apply. For a narrow convention, choose an appropriate file scope instead. A plain .md file in this directory is ignored.

   Illustrated exampleFrom request to a checkable result

   1. 01Real convention
   2. 02Correct .mdc file
   3. 03Appropriate scope

3. 3

   Step 3: Keep the instruction testable

   State what the agent should do, the reference file, and how to check the result. Keep secrets and personal data out of shared rules.

   Review the rule’s scope and text. Rules are instructions supplied to the model; use review and checks to confirm behavior rather than assuming perfect compliance.

4. 4

   Step 4: Try it in a fresh task

   Start a new chat and ask Cursor to describe how the rule affects one small proposed edit. Check that it identifies the intended convention.

   If the rule is missing, inspect its extension, scope, and referenced paths. Revise the rule, then test again before relying on it for larger work.

   Illustrated exampleCheck the recovery path

   1. Start fresh chat
   2. 02Try one small task
   3. 03Check the output

Help me create a concise Cursor project rule for [convention]. Inspect [reference files] first. Use .cursor/rules/[name].mdc and explain the appropriate scope. Include the real existing verification command if applicable. Do not add dependencies or change application code. Then explain one small task I can use to check that the rule applies.