datetime-timezone
Handle datetime and timezone conversions correctly across frontend, API, and database. Use this skill when working with datetime-local inputs, scheduling features, due dates, reminders, or any time-sensitive functionality. Covers the critical pitfall of browser datetime-local inputs lacking timezone info.
working-with-documents
Creates and edits Office documents: Word (.docx), PDF, and PowerPoint (.pptx). Use when working with document creation, PDF manipulation, presentation generation, tracked changes, or converting between formats.
working-with-spreadsheets
Creates and edits Excel spreadsheets with formulas, formatting, and financial modeling standards. Use when working with .xlsx files, financial models, data analysis, or formula-heavy spreadsheets. Covers formula recalculation, color coding standards, and common pitfalls.
python-data-stack
Statistical modeling toolkit. OLS, GLM, logistic, ARIMA, time series, hypothesis tests, diagnostics, AIC/BIC, for rigorous statistical inference and econometric analysis.
data-transform
Transform raw data into analytical assets using ETL/ELT patterns, SQL (dbt), Python (pandas/polars/PySpark), and orchestration (Airflow). Use when building data pipelines, implementing incremental models, migrating from pandas to polars, or orchestrating multi-step transformations with testing and quality checks.
fastapi-backend
Build production-grade FastAPI backends with SQLModel, Pydantic, and JWT authentication. Use this skill when building REST APIs, integrating with Neon PostgreSQL, implementing Better Auth JWT verification, or creating CRUD endpoints. Includes patterns for audit logging, worker/agent parity, and OpenAPI documentation.
chain-load
Load a chain to restore context from previous work. Use anytime when working on related topics - proactively search and suggest relevant chains.
langchain-patterns
Implement Retrieval-Augmented Generation (RAG) systems with LangChain4j. Build document ingestion pipelines, embedding stores, vector search strategies, and knowledge-enhanced AI applications. Use when creating question-answering systems over document collections or AI assistants with external knowledge bases.
prompt-engineering
Engineer effective LLM prompts using zero-shot, few-shot, chain-of-thought, and structured output techniques. Use when building LLM applications requiring reliable outputs, implementing RAG systems, creating AI agents, or optimizing prompt quality and cost. Covers OpenAI, Anthropic, and open-source models with multi-language examples (Python/TypeScript).
building-rag-systems
Build production RAG systems with semantic chunking, incremental indexing, and filtered retrieval. Use when implementing document ingestion pipelines, vector search with Qdrant, or context-aware retrieval. Covers chunking strategies, change detection, payload indexing, and context expansion. NOT when doing simple similarity search without production requirements.
chatgpt-app
Guidance for building the chatgpt-app (Vite + React + @openai/apps-sdk-ui) with the MCP-friendly single-file output.
memory-systems
Design and implement memory architectures for agent systems. Use when building agents that need to persist state across sessions, maintain entity consistency, or reason over structured knowledge.
ai-engineer
Use when building production-grade GenAI, Agentic Systems, Advanced RAG, or setting up rigorous Evaluation pipelines.
tool-design
Design tools that agents can use effectively. Use when creating new tools for agents, debugging tool-related failures, or optimizing existing tool sets.