Curated guardrails to stop Cursor from freelancing

What it does This repository is a curated catalog of Markdown-based .mdc files for the Cursor AI editor. Drop a file into .cursor/rules/ and Cursor suddenly knows your framework quirks, preferred libraries, naming conventions, and security constraints instead of generating generic boilerplate. The list spans frontend frameworks, backend stacks, mobile development, databases, testing, and even Shopify Liquid themes.

The interesting bit These files are essentially version-controlled system prompts. One Next.js 15 ruleset includes 27 architecture constraints to prevent specific AI hallucinations like insecure Supabase auth patterns or missing row-level security. It turns editorial guesswork into repeatable, shareable configuration.

Key highlights

• Covers frontend, backend, mobile, games, CSS, state management, databases, testing, and security.
• Includes framework-specific guardrails for React Router v7, Svelte 5 vs. Svelte 4, Next.js App Router, and Solid.js.
• Some rulesets target narrow failure modes, such as Stripe key exposure or deprecated Supabase imports.
• Shared .mdc files keep every contributor’s AI assistance consistent across a team.
• Uses the modern .mdc Project Rules format.

Verdict Worth bookmarking if you use Cursor and tire of correcting the AI’s framework guesses. Skip it if you want a library or CLI tool—this is purely a catalog of configuration templates.