Describe what you want
Type a plain-English request — "a habit tracker with streaks" — or start from one of 15 free templates for an instant, zero-cost v1. Either way, you land in a chat interface next to a live preview pane, not a code editor.
See the cost before it runs
A live estimate appears in the composer before you send. Generation is streamed from Claude and produces one complete, self-contained HTML app — styling and logic included, no partial files. If the generation fails, its cost is tracked separately and never billed to your build spend; if you report the same bug twice, the AI stops repeating itself and re-diagnoses from scratch instead.
Review the diff and the security scan
Every change lands as a new version with a line-by-line diff against the last one — roll back with one click if you don't like it. In parallel, the build is checked for hardcoded API keys and secrets, eval() / dynamic code execution, and other common AI-coding security mistakes, with the verdict shown as a pass/fail badge on the Security tab.
Download it, or publish it
Download the app as a single portable .html file you can run anywhere — no lock-in, the code is always fully visible. Or publish it to a shareable link; publishing re-runs the security scan server-side and refuses to go live if a critical issue is found, so a bypassed client-side check can never leak onto the public internet.
＋Two ways to pay for it
Bring your own Anthropic API key and pay Anthropic directly at their standard rates — we add no markup and never see your key or your invoice. Or take the $15/month Managed plan and we cover up to $10/month of usage on our own key, no API key required. See full details on the pricing section and the user guide.