A Guide to understand new .cursor/rules in 0.45 (.cursorrules)

multi-agent
Score: 57 | Author: kevinkernx | Subreddit: r/cursor
Author

kevinkernx

Published

February 8, 2025

Post Content

https://preview.redd.it/5j7okcqn2rhe1.png?width=1600&format=png&auto=webp&s=6bf0e0777b4416bcbdd999fa8d9d00c5419bbc46

Here is a complete thread on using cursor rules in 0.45 and especially the .cursor/rules dir

Blog Post:

https://www.instructa.ai/en/blog/how-to-use-cursor-rules-in-version-0-45

X Thread (+ Updates)

https://x.com/kregenrek/status/1887574770474229802

Update 1:

You can “stack” your cursor rules.

In the screenshot you can see that I have a “global” rule and a specific rule for extensions.

you can also see that in the reasoning step in the composer.

Sidenote: Some User reports that it crashes cursor so use this with caution

https://preview.redd.it/4uohiqe8nzhe1.png?width=3840&format=png&auto=webp&s=a6ac92154faf0524550572f4370f08e3308da852

Update 2:

Cursor Rules supports inheritance. If you have ever worked with CSS, this should be a familiar concept.

For example, create a base .mdc rule and reference it in your other rules. Keeps everything clean and separate.

https://preview.redd.it/7afrwoebnzhe1.png?width=2926&format=png&auto=webp&s=ebdd4b57e70420ff1d9080527aad0ee1a58ba684

Update 3:

Regarding deprecated .cursorrules. Smth. in me hopes that doesn’t happen → everyone needs to migrate. In the long run, the name .cursorrules is an understatement of the agent’s powerful capabilities.

Workaround: Create an [whateveryouwant].mdc (agent was just an example) file as an replacement for the .cursorrules. Add the “*” for global (missed it in the screenshot)

https://preview.redd.it/9nqczhydnzhe1.png?width=2722&format=png&auto=webp&s=f738d76a4510f81b8f882cf9dd964f79d64c4b26

Key Takeaways

  • “Sidenote: Some User reports that it crashes cursor so use this with caution

https://preview” - “If you have ever worked with CSS, this should be a familiar concept”