An AI app builder from RocketSocial SASU, a French company. Describe the app you want in plain language, and it generates a full-stack application covering the frontend, backend, and database. What sets it apart is that it does not start writing code immediately — the AI first asks who will use the app, what it should accomplish, and how it should look, then firms up the spec before building. Finished apps can be published to the internet with one click and connected to a custom domain. Beyond web apps, it can generate native mobile apps, and a Mac desktop app is distributed free of charge.
Key Features
- Asks before it builds: So that you do not need to be good at writing prompts, the AI confirms the purpose, target users, and design direction while assembling the spec. This helps avoid the classic failure of starting from one vague sentence and getting something off target
- Vibe and Spec, used as needed: You can switch between a “Vibe” approach that turns an idea into something tangible right away, and “Spec Coding,” where a planning assistant writes the spec down before construction begins. Use the former while prototyping and the latter when building things out
- Production essentials included from the start: You can implement what real products have — login, member accounts, data persistence, and payments. It integrates with outside services such as Supabase (database), Stripe (payments), and Google Auth
- Web, mobile, and desktop: In addition to web apps, it generates native iOS and Android apps via Expo. A Mac desktop app is also offered as a working environment
- One-click deploy and custom domains: Apps go straight through to publication, and you can connect your own domain within minutes. Environment variable management is supported, so API keys need not be written directly into the code
- Codebase export: Higher plans let you export the generated codebase. Output uses a common stack — Next.js, TypeScript, Tailwind CSS — leaving open the path to move to conventional development partway through
Pricing
| Plan | Monthly | What’s included |
|---|---|---|
| Starter | $25 | 100 credits, unlimited projects, agentic mode, email support |
| Growth | $69 | 250 credits, codebase export, custom domains, dedicated support channel |
| Professional | $129 | 500 credits, everything in Growth, premium support, early access to new features |
| Business | $299 | 1,000 credits, everything in Professional, dedicated success manager, custom integrations |
Credits can also be bought outright in three packs: 10 credits for $9, 50 credits for $39, and 100 credits for $69. Credits are consumed per message to the AI agent, and the amount varies with the complexity of the task (simple fixes use fewer; adding features or debugging uses more). Purchased credits do not expire.
Note that the official pricing page lists no free plan. The Mac desktop app itself is distributed free and requires no credit card.
Pricing is current as of August 2026. For the latest pricing, including whether annual plans are offered, please check the official site.
Pros & Cons
✅ Pros
- Because the AI asks the questions, beginners who struggle with prompts can still pin down requirements
- Lets you build a working product end to end, including login, payments, and a database
- Handles one-click publishing and custom domain connection, so you are less likely to stall right before launch
- Covers mobile apps as well as web, through the same flow
- Codebase export means you can hand the project over to conventional development later
⚠️ Cons
- There is no free plan; trying it out requires at least the $25/month tier
- The credit model makes costs hard to predict as you build out — complex feature work and debugging consume more credits
- Codebase export and custom domains require Growth ($69/month) or above and are unavailable on the cheapest plan
- No Japanese documentation is provided; official information is primarily in English
- Verifying the quality and security of the generated code ultimately remains the user’s responsibility
Comparison with Similar Services
| Criteria | Capacity | Lovable | Bolt.new | Replit |
|---|---|---|---|---|
| Main use | Full-stack web/mobile app generation | Web app generation | In-browser web app development | Browser-based dev environment |
| Approach | AI asks questions to firm up the spec | Iterative generation from prompts | Iterative generation from prompts | Agent plus a conventional IDE |
| Mobile apps | Supported (Expo) | Limited | Limited | Supported (Expo) |
| Free plan | None | Yes | Yes | Yes |
| Code export | Supported (Growth and up) | Supported | Supported | Supported |
Pricing and free allowances change often across these services, so check each official site for current details when comparing.
Who Is It For
- Non-technical founders who have an idea but cannot write code, and want to ship something working first
- Anyone who needs an MVP including login and payments, quickly, to validate a new business
- People who are unsure about writing prompts and would rather have the AI ask
- Teams that want to prototype web and mobile in the same environment
- Developers who want the AI to produce a first draft, on the assumption of moving to conventional development later
Summary
Among AI app builders, Capacity puts its weight on reaching agreement before construction starts. Rather than spitting something out from a single prompt, it settles the spec through questions first — a design that benefits people least comfortable with prompting. With login, payments, and custom domains all covered, the distance from a rough idea to something testable is short. That said, with no free plan and a credit-based model, the practical approach is to start small on Starter and consider a higher tier once it is clear the project is worth building out.