Massvai
Build production-ready apps, from a single prompt
About Massvai
Massvai is an AI app builder built around one stack: it turns a plain-language prompt, optionally with a screenshot or reference file, into a full-stack Next.js application written in TypeScript with Tailwind CSS, Supabase auth and a live preview. A durable AI coding agent plans the work before it writes code and preserves progress across long-running tasks, and the finished project can be synced to GitHub and deployed to Vercel from one guided publishing flow. It is aimed at the gap between quick AI prototypes and code a team can inspect, own and ship.
Its distinguishing points are an opinionated Next.js, Supabase and Vercel stack and an emphasis on code ownership: every file can be exported, and the site promises no lock-in. Massvai is a young product - its legal pages carry an effective date of August 5, 2026 - and the site does not name the company behind it. Pricing is credit-based. Each agent generation uses credits; the Free plan gives 100 one-time welcome credits rather than a monthly allowance, while Builder and Pro add credits every month. Payments run through Stripe.
You sign in with Google, GitHub or email and describe the app in plain language, adding a screenshot or reference file when the details matter. The agent plans first, then scaffolds a Next.js 15 and React 19 project with a Tailwind design system, wires up Supabase auth, and builds the interface.
Progress stays visible throughout. A live preview with hot module replacement updates as the agent writes code, and the workspace keeps durable progress and tool history, with Stop and Retry controls when a run needs to be interrupted or repeated. The sign-in page also lists a visual element editor.
When the app is ready, you review every file, push the codebase to GitHub and deploy it to Vercel from the same flow. Pro adds Supabase setup assistance and version history with restore. Code export is available on every plan, including Free.
- •Durable AI coding agent - Plans before it builds, writes maintainable code, handles edge cases and keeps progress across long-running tasks, with tool history plus Stop and Retry.
- •Full-stack Next.js output - Projects use Next.js 15, React 19, TypeScript and Tailwind CSS with Supabase; the site also lists Stripe and Prisma among the tools it works with.
- •Live preview - A real-time preview with hot module replacement shows the app as it is built.
- •GitHub sync and Vercel deploy - A reviewed codebase goes to GitHub and Vercel in one guided flow, with custom preview domains on paid plans.
- •Full code export - Every file can be exported on every plan, and the site states you own the generated code.
- •Supabase setup and version history - The Pro plan adds Supabase setup assistance, version history and restore, and priority product support.
Massvai describes its users as founders, product teams, agencies and developers who need more than a prototype. Solo builders shipping an MVP fit the Builder plan, while founders and teams building every week are the target for Pro. Typical projects named on the site are a SaaS MVP with authentication, dashboards and billing-ready UI, internal tools built from operational workflows, and responsive client websites deployed on a production domain.
Developers who already use Next.js, Supabase and Vercel get code in a familiar shape they can review and keep working on elsewhere. It is less of a fit for anyone who needs a different framework or host, since the stack is fixed. The Free plan's 100 credits are one-time, so it suits a first project rather than ongoing use, and buyers should weigh that the product is new and its operator is not identified on the site.
