Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add rules/ryanrawlingswang/llm-rules/nextjs-developmentgit clone --depth 1 https://github.com/ryanrawlingswang/llm-rulesWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.05257 | $0.05257 |
| Opus 5 | $0.02629 | $0.02629 |
| Sonnet 5 | $0.01051 | $0.01051 |
| Haiku 4.5 | $0.00526 | $0.00526 |
Grade A, and why
nextjs-development scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
1 near-identical copy found in the catalogue:
- nextjs-development — 97% identical, 4 lines differ
How it starts
The opening of the file, as written. The whole thing — 806 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Next.js Development Rules
You are an expert full-stack TypeScript engineer working with Next.js. Produce production-ready code that follows modern Next.js App Router patterns and best practices.
Tech Stack Guidelines
- Next.js 15+ (App Router) + React 19
- TypeScript (strict mode)
- Testing: Vitest + React Testing Library + MSW
- Styling: Tailwind CSS + shadcn/ui (when applicable)
- Package Manager: pnpm
Focus on: separation of concerns, strict typing, accessibility, performance, and comprehensive testing.
Project Structure
src/
├─ app/ # App Router (RSC by default)
│ ├─ _components/ # App-level (RSC-ok) components
│ ├─ api/ # API routes for external webhooks only
│ ├─ (routes)/ # Route groups and pages
│ └─ layout.tsx
├─ components/ # Reusable client/RSC components
│ ├─ ui/ # Base UI components
│ └─ [feature]/ # Feature-specific components
├─ lib/ # Utilities and shared helpers
├─ server/ # Server-side code
│ ├─ api/ # tRPC API layer
│ │ ├─ routers/ # tRPC router composition
│ │ ├─ procedures/ # Individual tRPC procedures
│ │ ├─ root.ts # Root router
│ │ └─ trpc.ts # tRPC setup
│ ├─ services/ # Business logic services
│ └─ clients/ # External service clients
├─ db/ # Database schema & migrations
├─ tools/ # AI tool definitions
├─ prompts/ # AI prompt templates
└─ trpc/ # tRPC client setup
test/
├─ unit/ # Unit tests
├─ integ/ # Integration tests
└─ e2e/ # End-to-end tests
Directory Conventions
- Use kebab-case for folders and files
- Co-locate tests next to source:
*.test.ts(x) - Export from
index.tsbarrels only when it helps DX without circular deps
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2d ago First seen · 806 lines · 5,257 tokens per session scan A 9ac766d7c2b3
nextjs-development is a cursor rule published in the GitHub repository ryanrawlingswang/llm-rules (17 stars, last pushed 2mo ago), licensed MIT. It adds 5,257 tokens to every session, about $0.0263 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other cursor rules, from other repositories
angular-20
This rule provides comprehensive best practices and coding standards for Angular development, focusing on modern TypeScript, standalone components, signals, and performance optimizations.
dev-standard
Apache Superset development standards and guidelines for Cursor IDE.
typescript
Changes to these high-fan-out internals can affect every message, delta, element, or rerun. Keep work in them minimal, and benchmark changes with representative stress-test apps.
coolify-ai-docs
Master reference to all Coolify AI documentation in .ai/ directory.
python_lib
Tips and guidelines specific to the development of the Streamlit Python library, not applicable to scripts and e2e tests.
specs
This directory contains product and tech specs for Streamlit features.