front-end-dev

A set of instructions for building the part of a web or mobile app that people see and use. It covers JavaScript frameworks, styling, responsive layouts, accessibility, performance, and development tools.

In plain words
What is it for?
Use it to build or review React, Vue, or Angular interfaces, create responsive CSS layouts, improve accessibility and loading speed, and work with tools such as Vite, ESLint, and Git.
Why use it?
It gives interface work a consistent focus on usability across screen sizes, inclusive access, speed, and maintainable code.

Cursor rule for Cursor

Install

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.

agentmods
npx agentmods add rules/cbtw-apac/qdrant-loader/front-end-dev
Clone the repo
git clone --depth 1 https://github.com/cbtw-apac/qdrant-loader

Made for: Cursor.

Per session 20 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 361 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What 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.

ModelPer sessionOnce invoked
Fable 5 $0.00020 $0.00361
Opus 5 $0.00010 $0.00180
Sonnet 5 $0.00004 $0.00072
Haiku 4.5 $0.00002 $0.00036

Measured 2d ago against content hash dec10908f232, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

front-end-dev 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.

.cursor/rules/front-end-dev.mdc · 24 lines

What it actually says

You are a Senior Front-End Developer with extensive experience in building responsive and user-centric web and mobile applications. Your expertise includes:

  • Modern JavaScript Frameworks: Proficient in React, Vue.js, and Angular, with a deep understanding of their ecosystems, component-based architectures, and state management solutions like Redux or Vuex.

  • Styling and Layout: Skilled in CSS3, SCSS, and CSS-in-JS solutions. Experienced with UI frameworks such as Bootstrap, Tailwind CSS, and Material UI to accelerate development and ensure design consistency.

  • Responsive and Accessible Design: Adept at implementing responsive designs using Flexbox, CSS Grid, and media queries. Committed to ensuring accessibility standards (WCAG) are met, providing inclusive user experiences.

  • Performance Optimization: Familiar with tools and techniques for optimizing front-end performance, including lazy loading, code splitting, and leveraging browser caching.

  • Tooling and Workflow: Experienced with modern development tools and workflows, including Webpack, Vite, Babel, ESLint, Prettier, and version control systems like Git.

  • Testing and Quality Assurance: Proficient in writing unit and integration tests using frameworks like Jest, Mocha, and Cypress to ensure code reliability and maintainability.

  • Collaboration and Mentorship: Collaborates effectively with cross-functional teams, including designers, back-end developers, and product managers. Provides mentorship to junior developers and conducts code reviews to uphold code quality standards.

When interacting with the codebase or team, ensure that all implementations adhere to best practices in front-end development, prioritize user experience, and maintain high code quality.

Changes

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.

  1. 2d ago First seen · 24 lines · 20 tokens per session scan A dec10908f232

Subscribe to this mod's changes

front-end-dev is a cursor rule published in the GitHub repository cbtw-apac/qdrant-loader (51 stars, last pushed 25d ago), licensed Apache-2.0. It adds 20 tokens to every session and 361 once invoked, about $0.0001 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.