Spec Kit is an open-source development toolkit from GitHub designed for Spec-Driven Development (SDD) — a methodology that puts specifications first, using them as the source of truth for building software with AI-assisted tools. It helps developers focus on what needs to be built (the specification) before how it’s implemented, enabling more predictable and structured AI-powered development workflows.

Key Features#

• Specification-First Workflow: Specifications become executable artifacts that guide planning, task creation, and implementation.
• AI Integration: Works with AI coding agents such as GitHub Copilot, Claude Code, and Gemini CLI to generate implementations from specs.
• CLI Tools: Includes the specify command-line interface to bootstrap projects, check environment tools, and manage workflows.
• Structured Workflow Commands: Slash commands like /speckit.constitution, /speckit.specify, /speckit.plan, /speckit.tasks, and /speckit.implement guide the development cycle.

How It Works#

Spec Kit replaces traditional code-first workflows with a specification-centric process:

1. Define project principles and standards (/speckit.constitution).
2. Write detailed specs describing the feature or product intent (/speckit.specify).
3. Generate a technical plan based on the spec (/speckit.plan).
4. Break that plan into tasks for implementation (/speckit.tasks).
5. Execute or generate implementation through the AI assistant (/speckit.implement).

This method aims to reduce guesswork, increase alignment between generated code and requirements, and make AI-assisted development more consistent and maintainable.

Why It Matters#

• Improves AI-driven workflows by giving coding agents a precise and persistent understanding of goals.
• Encourages high-quality output with detailed planning and clear specifications.
• Aids team collaboration by using specs as a shared source of truth rather than loose instructions.