Spec Builder interviews you about your requirements, then streams a complete markdown specification — architecture, data models, API routes, and implementation roadmap — ready for Claude Code, Cursor, or any AI coding agent.
Sign up · Purchase tokens · First spec in under 5 minutes
Spec Builder actively interviews you, then produces a specification structured for the way AI coding agents actually read and reason about requirements.
Before generating a single word, the AI interviews you — probing edge cases, user flows, and architectural decisions that most developers overlook.
Every spec includes Overview, Architecture, Data Models, API Design, File Structure, Auth, Error Handling, Testing, Deployment, and Implementation Roadmap.
Choose framework, UI library, database, and auth method. The spec is written specifically for your chosen stack — not a generic template.
Give the AI live access to your existing codebase via Model Context Protocol server URLs — so specs integrate with what you've already built.
Every spec includes an interactive AI chat with full document context. Change architecture decisions, expand sections, or add requirements in natural language.
Choose from GPT-4, Claude, Gemini, and more. Switch models per spec or per refinement pass to balance quality, speed, and token cost.
Download your finished spec in any format — drop the Markdown file directly into Claude Code, Cursor, or any AI coding agent as a system prompt.
Share specs with clients or external collaborators via a public link. Access is controlled by a one-time password — no account required for viewers.
The entire process takes under 10 minutes. Here's exactly what happens when you create a spec.
Start with a plain-language description of what you want to build. No technical jargon required — just describe the problem your app solves and who uses it.
Choose the technologies your app will be built with. Spec Builder tailors every section — from file structure to API design — to your exact stack.
The AI asks smart follow-up questions about the aspects of your app it needs to understand — authentication flows, user roles, data relationships, edge cases.
Watch your complete technical specification generate in real time. Each of the 10 sections streams in — ready to review, edit, or refine with the AI chat.
Download your spec as Markdown and paste it directly into Claude Code, Cursor, or GitHub Copilot as a system prompt. Your AI agent will have everything it needs.
Each spec is structured to give your AI coding agent a complete mental model of the system before it writes a single line of code. No follow-up clarifications needed.
AI coding agents produce far better results when they have a complete, structured specification to work from. Spec Builder creates that specification in minutes.