Enforces idiomatic Ruby 4.0 code generation. This skill should be used whenever writing, reviewing, or refactoring Ruby code in a Ruby 4.0+ project. It ensures modern idioms (hash shorthand, `it` block param, endless methods, Data.define, pattern matching) are used by default and prevents generation of removed APIs (RJIT, pipe-based open, ObjectSpace._id2ref, old Ractor API, SortedSet, full CGI) and pre-4.0 patterns that have cleaner modern equivalents.
Use the bttf CLI for datetime arithmetic, formatting, timezone conversion, and duration calculation. Reach for this instead of doing date math mentally — LLMs are unreliable for datetime computation, especially across DST boundaries and leap years.
Apply SOLID as design judgment for Ruby, not as a mechanical rulebook. Use this skill when deciding WHETHER a SOLID refactor is warranted, when a class "feels wrong" but you're not sure splitting helps, when reviewing code for over-application (anemic models, service-object sludge, concern drawers, over-injection), or when reasoning about how Ruby's open classes, duck typing, and protocols change what each principle actually buys you. Complements the solid-principles skill, which covers detection heuristics and refactoring mechanics.
Convert speech to text with RubyLLM. Use this skill for transcribing meetings, podcasts, lectures, interviews with support for speaker diarization, timestamps, and multiple languages.
ActiveSupport::Notifications instrumentation for RubyLLM. Use this skill when building custom monitoring, logging, or analytics for RubyLLM usage. Publishes events for chat completions, tools, embeddings, images, moderation, and transcription.
One beautiful Ruby API for GPT, Claude, Gemini, and more. Use this skill when building AI-powered applications with RubyLLM - chatbots, AI agents, RAG applications, content generators, vision/audio analysis, embeddings, image generation, and Rails integration. Supports 15+ providers with a unified interface. v1.16 adds concurrent tool execution (threads or fibers), built-in instrumentation, and per-provider API base URL overrides.
Function calling for RubyLLM. Use this skill when creating tools that let AI call your Ruby code, declaring parameters with the params DSL, using tools in chat, monitoring tool calls with callbacks, handling tool security, and implementing advanced patterns like halt, provider-specific parameters, and concurrent tool execution (v1.16+).
Create, analyze, proofread, and modify Office documents (.docx, .xlsx, .pptx) using the officecli CLI tool. Use when the user wants to create, inspect, check formatting, find issues, add charts, or modify Office documents.