nanci

Expert skill for building CLI applications with Cobra and Viper, authored by spf13 — the original creator of both libraries. Covers command-first architecture, decoupled business logic, configuration management, environment variable binding, context-aware commands, and in-memory CLI testing. Use when building or reviewing any Go CLI application that uses Cobra and/or Viper.

Expert Go programming skill authored by spf13 (former Go team lead, author of Cobra, Viper, Hugo, Afero). Covers idiomatic Go — package design, error handling, interfaces, concurrency, testing, and project layout. Use when writing, reviewing, or refactoring any Go code.

Review design specification documents for Go programs before implementation begins. Use this skill when a user has a Go spec to review, wants feedback on a design doc, is about to start implementing from a spec, asks "is this spec ready?", or wants a technical review of a planned feature in a Go codebase. Applies Go philosophy — simplicity, composition, explicit errors, context propagation — plus Cobra/Viper CLI conventions where applicable.