The definitive guide to Spec-Driven Development: build software with AI agents, from method to production code. Book in EN + pt-BR with a ready-to-use SDD kit for Claude Code.
felipefontoura/spec-driven-development-book
Skill Claude CodeCodex
Explicit command-style skill for implementing approved SDD tasks from tasks.md with tight scope, tests, and verification evidence. Use only when the user explicitly asks to execute or implement a specific approved SDD task or feature. Do not auto-load for discussion, planning, review, or unapproved tasks.
felipefontoura/spec-driven-development-book
Skill Claude CodeCodex
Conversational SDD skill for exploring raw product or feature ideas before planning. Use when the user wants to brainstorm, clarify, compare directions, or convert an early idea into a plan or requirements, even without an explicit command. Do not use for implementation or technical task execution.
felipefontoura/spec-driven-development-book
Skill Claude CodeCodex
Explicit command-style skill for initializing or adopting SDD in a project by creating or preparing .ai/, .ai/steering/, and .ai/sdd/. Use only when the user explicitly asks to initialize, set up, adopt, or bootstrap SDD. Do not auto-load for general planning, feature specs, status checks, or implementation.
felipefontoura/spec-driven-development-book
Skill Claude CodeCodex
Cognitive SDD skill for creating or updating optional PLAN.md from captured ideas or project goals. Use when the conversation calls for roadmap, personas, feature mapping, phases, dependencies, and open decisions before requirements, even without an explicit command. Do not use for feature-level requirements or coding.
felipefontoura/spec-driven-development-book
Skill Claude CodeCodex
Core cognitive SDD skill for creating or updating requirements.md from an approved idea, plan, or feature request. Use when the conversation calls for defining WHAT and WHY: user stories, acceptance criteria, EARS functional requirements, NFRs, and boundaries, even without an explicit command. Do not use for technical…
felipefontoura/spec-driven-development-book
Skill Claude CodeCodex
Cognitive SDD skill for reviewing an implementation against requirements.md, design.md, and tasks.md, producing review.md with coverage, findings, verification evidence, and merge readiness. Use when the conversation calls for review after implementation or before completion, even without an explicit command. Do not…
felipefontoura/spec-driven-development-book
Skill Claude CodeCodex
Core cognitive SDD skill for creating design.md technical specifications from approved requirements. Use when the conversation calls for HOW decisions: architecture, components, data/state, APIs, flows, edge cases, technical decisions, risks, and implementation FAQ, even without an explicit command. Do not use for…
felipefontoura/spec-driven-development-book
Skill Claude CodeCodex
Explicit command-style skill for inspecting .ai/sdd state and recommending the next safe action. Use only when the user explicitly asks for SDD status, progress, blockers, readiness, or next action. Do not auto-load for general SDD work; do not create specs or implement code.
felipefontoura/spec-driven-development-book
Skill Claude CodeCodex
Creates or updates reusable project steering documents in .ai/steering for product context, tech stack, conventions, and domain-specific guidance. Use when shared AI context needs to be established or corrected, but confirm before saving durable/global steering changes. Do not use for feature-level requirements or…
felipefontoura/spec-driven-development-book
Skill Claude CodeCodex
Core cognitive SDD skill for decomposing an approved design.md into practical tasks.md. Use when the conversation calls for implementation planning, task dependencies, estimates, acceptance criteria, file targets, and verification steps, even without an explicit command. Do not use for technical design or direct…
At most 3 mods per repository are shown here, and a mod shipped inside a plugin is left to that plugin's page — the rest are on their repository pages: