SpecWriter: AI-Powered Spec Writing
Claude Code builds 70% of what you describe perfectly. The other 30%? Edge cases you forgot to mention. Loading states you assumed were obvious. Features buried in paragraph four that never got implemented. This is the 30% problem — and SpecWriter exists to solve it.
SpecWriter is an AI-powered conversation that draws out every detail, writes a professional specification document, and generates a verification checklist. The Implementation Guide breaks it into sessions. Self-Drive implements them all automatically — from idea to finished feature, without manual intervention.
From idea to implementation-ready spec in minutes
Seven steps. From idea to finished feature — automatically.
Describe what you want
Start a conversation with SpecWriter. Describe your idea in plain language. The AI asks targeted clarifying questions with selectable options — pulling out the details you would naturally skip.
Attach mockups and references
Drag in screenshots, wireframes, PDFs, or design files. SpecWriter analyzes visual references and incorporates their details into the specification — layout, spacing, component hierarchy, interactions.
AI reads your codebase
For feature specs, SpecWriter reads your existing project files. It understands your stack, component patterns, database schema, and naming conventions — so the spec references real paths and real code.
AI writes the specification
SpecWriter generates a professional, structured specification document covering architecture, data models, UI components, API endpoints, error handling, edge cases, and accessibility — everything a developer (or an AI) needs to build it right.
AI generates a verification checklist
Every spec comes with a companion verification checklist — a step-by-step QA plan you can follow after implementation to confirm every requirement was met. No more "I think it's done."
Generate an Implementation Guide
Click Implement to generate a structured, multi-session plan. The guide breaks your spec into ordered sessions — each with a clear scope, pre-built prompts, and a verification checklist. For single-session features, send the spec directly to Claude Code instead.
Self-Drive implements it all
Click Start Self-Drive and walk away. The AI orchestrator sends each session's prompt to Claude Code, verifies the output, fixes errors, runs build checks and tests, and advances through every session automatically. You come back to a finished feature.
New app or new feature — SpecWriter adapts
Whether you are starting from scratch or adding to an existing codebase, SpecWriter tailors the conversation and the output to match your situation.
New Application
Start from zero
Building something entirely new? SpecWriter generates a comprehensive 10-section specification covering everything Claude Code needs to scaffold your project from an empty folder.
Feature Mode
Add to an existing project
Adding a feature to an existing codebase? SpecWriter reads your project files first. The resulting spec references your real file paths, your real component names, and your real data models.
Confidence Tags
SpecWriter tells you when it is guessing. Every recommendation in Feature Mode is tagged with a confidence level:
Know when it's actually done
Every specification comes with a companion verification checklist — a structured QA plan generated from the spec itself. After Claude Code implements the feature, walk through the checklist to confirm every requirement was met, every edge case was handled, and every interaction works as specified.
- Auto-generated from the specification document
- Covers functional requirements, edge cases, and accessibility
- Step-by-step — no ambiguity about what to test
- Catch missing features before they reach users
The spec is the product.
Not the prompt.
When you give Claude Code a chat message, it does its best with what you wrote. When you give it a specification document, it has a contract. Loading states? Documented. Error messages? Specified. That obscure edge case with the empty cart and the expired coupon? Covered in section 7.
No other Claude Code wrapper has anything like SpecWriter. It is the difference between “build me a dashboard” and a document that defines every chart, every filter, every empty state, every permission check, and every animation — before a single line of code is written.
Stop describing. Start specifying.
Download CodeMantis, open SpecWriter, and see what happens when Claude Code gets a real specification instead of a chat message.