Languages & Frameworks for Claude Code

React useEffect best practices from official docs. Use when writing/reviewing useEffect, useState for derived values, data fetching, or state synchronization. Teaches when NOT to use Effect and better alternatives.

Use when you need to transform poorly structured, complex, or duplicated code into clean, maintainable systems while preserving all existing behavior. Specifically:\\n\\n<example>\\nContext: A codebase has methods exceeding 200 lines, deeply nested conditionals, and 15% code duplication across similar functions.\\nuser: \"Help me refactor this legacy payment processing module. The methods are too long and the logic is hard to follow.\"\\nassistant: \"I'll analyze the code for smells like long me

Best practices for Remotion - Video creation in React

An uncompromising Academic Research Engineer. Operates with absolute scientific rigor, objective criticism, and zero flair. Focuses on theoretical correctness, formal verification, and optimal implementation across any required technology.

Expert assistance for building Model Context Protocol servers in Ruby using the official MCP Ruby SDK gem with Rails integration.

Write idiomatic Ruby code with metaprogramming, Rails patterns, and performance optimization. Specializes in Ruby on Rails, gem development, and testing frameworks.

Plan and build production-ready Rust CLI tools using clap for argument parsing, with subcommands, config file support, colored output, and proper error handling. Uses interview-driven planning to clarify commands, input/output formats, and distribution strategy before writing any code.

Use when building Rust systems where memory safety, ownership patterns, zero-cost abstractions, and performance optimization are critical for systems programming, embedded development, async applications, or high-performance services. Specifically:\\n\\n<example>\\nContext: Designing a high-throughput async network service that must handle thousands of concurrent connections with minimal memory overhead and strict latency requirements\\nuser: \"Create a tokio-based async service that processes 5

Rust GPT-4.1 Coding Beast Mode for VS Code

Expert assistant for Rust MCP server development using the rmcp SDK with tokio async runtime

Master Rust 1.75+ with modern async patterns, advanced type system features, and production-ready systems programming.

Write idiomatic Rust with ownership patterns, lifetimes, and trait implementations. Masters async/await, safe concurrency, and zero-cost abstractions. Use PROACTIVELY for Rust memory safety, performance optimization, or systems programming.

RNN+Transformer hybrid with O(n) inference. Linear time, infinite context, no KV cache. Train like GPT (parallel), infer like RNN (sequential). Linux Foundation AI project. Production at Windows, Office, NeMo. RWKV-7 (March 2025). Models up to 14B parameters.

Design and implement multi-tenant SaaS architectures with row-level security, tenant-scoped queries, shared-schema isolation, and safe cross-tenant admin patterns in PostgreSQL and TypeScript.

Expert patterns for Salesforce platform development including Lightning Web Components (LWC), Apex triggers and classes, REST/Bulk APIs, Connected Apps, and Salesforce DX with scratch orgs and 2nd generation packages (2GP). Use when: salesforce, sfdc, apex, lwc, lightning web components.

Provide expert Salesforce Platform guidance, including Apex Enterprise Patterns, LWC, integration, and Aura-to-LWC migration.

Master enterprise-grade Scala development with functional programming, distributed systems, and big data processing. Expert in Apache Pekko, Akka, Spark, ZIO/Cats Effect, and reactive architectures.

Biological data toolkit. Sequence analysis, alignments, phylogenetic trees, diversity metrics (alpha/beta, UniFrac), ordination (PCoA), PERMANOVA, FASTA/Newick I/O, for microbiome analysis.

Machine learning in Python with scikit-learn. Use when working with supervised learning (classification, regression), unsupervised learning (clustering, dimensionality reduction), model evaluation, hyperparameter tuning, preprocessing, or building ML pipelines. Provides comprehensive reference documentation for algorithms, preprocessing techniques, pipelines, and best practices.

Comprehensive toolkit for survival analysis and time-to-event modeling in Python using scikit-survival. Use this skill when working with censored survival data, performing time-to-event analysis, fitting Cox models, Random Survival Forests, Gradient Boosting models, or Survival SVMs, evaluating survival predictions with concordance index or Brier score, handling competing risks, or implementing any survival analysis workflow with the scikit-survival library.

Create, update, refactor, explain or work with code using the .NET version of Semantic Kernel.

Create, update, refactor, explain or work with code using the Python version of Semantic Kernel.

Comprehensive software architecture skill for designing scalable, maintainable systems using ReactJS, NextJS, NodeJS, Express, React Native, Swift, Kotlin, Flutter, Postgres, GraphQL, Go, Python. Includes architecture diagram generation, system design patterns, tech stack decision frameworks, and dependency analysis. Use when designing system architecture, making technical decisions, creating architecture diagrams, evaluating trade-offs, or defining integration patterns.

Comprehensive backend development skill for building scalable backend systems using NodeJS, Express, Go, Python, Postgres, GraphQL, REST APIs. Includes API scaffolding, database optimization, security implementation, and performance tuning. Use when designing APIs, optimizing database queries, implementing business logic, handling authentication/authorization, or reviewing backend code.

World-class computer vision skill for image/video processing, object detection, segmentation, and visual AI systems. Expertise in PyTorch, OpenCV, YOLO, SAM, diffusion models, and vision transformers. Includes 3D vision, video analysis, real-time processing, and production deployment. Use when building vision AI systems, implementing object detection, training custom vision models, or optimizing inference pipelines.

Comprehensive fullstack development skill for building complete web applications with React, Next.js, Node.js, GraphQL, and PostgreSQL. Includes project scaffolding, code quality analysis, architecture patterns, and complete tech stack guidance. Use when building new projects, analyzing code quality, implementing design patterns, or setting up development workflows.

World-class prompt engineering skill for LLM optimization, prompt patterns, structured outputs, and AI product development. Expertise in Claude, GPT-4, prompt design patterns, few-shot learning, chain-of-thought, and AI evaluation. Includes RAG optimization, agent design, and LLM system architecture. Use when building AI products, optimizing LLM performance, designing agentic systems, or implementing advanced prompting techniques.

Framework for state-of-the-art sentence, text, and image embeddings. Provides 5000+ pre-trained models for semantic similarity, clustering, and retrieval. Supports multilingual, domain-specific, and multimodal models. Use for generating embeddings for RAG, semantic search, or similarity tasks. Best for production embedding generation.

Language-independent tokenizer treating text as raw Unicode. Supports BPE and Unigram algorithms. Fast (50k sentences/sec), lightweight (6MB memory), deterministic vocabulary. Used by T5, ALBERT, XLNet, mBART. Train on raw text without pre-tokenization. Use when you need multilingual support, CJK languages, or reproducible tokenization.

Expert patterns for Shopify app development including Remix/React Router apps, embedded apps with App Bridge, webhook handling, GraphQL Admin API, Polaris components, billing, and app extensions. Use when: shopify app, shopify, embedded app, polaris, app bridge.

| Build Shopify apps, extensions, themes using GraphQL Admin API, Shopify CLI, Polaris UI, and Liquid. TRIGGER: "shopify", "shopify app", "checkout extension", "admin extension", "POS extension", "shopify theme", "liquid template", "polaris", "shopify graphql", "shopify webhook", "shopify billing", "app subscription", "metafields", "shopify functions"

Use this agent when building or customizing Shopify themes, developing Shopify apps, working with Liquid templating, or integrating Shopify APIs (Admin GraphQL, Storefront, Functions, Checkout Extensibility). Use PROACTIVELY for Online Store 2.0 section/block work, app architecture decisions, and headless Hydrogen storefronts. Specifically:\n\n<example>\nContext: A merchant needs a custom section built for their theme.\nuser: \"I need a featured collection section with configurable columns and a

Build Slack apps using the Bolt framework across Python, JavaScript, and Java. Covers Block Kit for rich UIs, interactive components, slash commands, event handling, OAuth installation flows, and Workflow Builder integration. Focus on best practices for production-ready Slack apps. Use when: slack bot, slack app, bolt framework, block kit, slash command.

Use this agent when developing Slack applications, implementing Slack API integrations, or reviewing Slack bot code for security and best practices. Specifically:\\n\\n<example>\\nContext: Developer is building a new Slack bot using @slack/bolt that needs to handle app mentions, respond to slash commands, and display Block Kit modals.\\nuser: \"I'm building a Slack bot that handles app mentions, slash commands, and interactive modals. Can you help me set it up with proper error handling and even

Use this agent for smart contract architecture and design-pattern advisory work — choosing proxy/upgrade patterns, designing storage layouts, defining module boundaries, and selecting token/protocol standards — rather than day-to-day implementation or security auditing. Examples: <example>Context: User needs to build a new DeFi protocol user: 'I need to create a secure lending protocol with upgradeable contracts' assistant: 'I'll use the smart-contract-specialist agent to design the contract arc

Guide for quality focused software architecture. This skill should be used when users want to write code, design architecture, analyze code, in any case that relates to software development.

Use this agent when building enterprise Spring Boot 3+ applications requiring microservices architecture, cloud-native deployment, or reactive programming patterns. Specifically:\\n\\n<example>\\nContext: User needs to design and implement a microservices architecture with Spring Cloud components and requires expertise in service discovery, circuit breakers, and distributed tracing.\\nuser: \"I'm building a microservices platform with 8 services. I need Spring Cloud setup, API Gateway configurat

Master modern SQL with cloud-native databases, OLTP/OLAP optimization, and advanced query techniques. Expert in performance tuning, data modeling, and hybrid analytical systems.