How It Works

Building an app with bld402 takes four simple steps. No coding, no technical knowledge, no sign-up required.

1. Open a coding agent

Open a coding agent — like Claude Code, ChatGPT Codex, Cursor, or Windsurf. Tell it what you want to build in plain language.

"I want to build a trivia game where I create questions and my friends can play by joining with a code."

2. Paste the bld402 link

Paste https://bld402.com into the chat. Your coding agent will fetch the instructions and know exactly what to do next.

"I want to build a trivia game. Here are the instructions: https://bld402.com"

3. Answer a few simple questions

Your coding agent will ask you a few yes/no or multiple-choice questions to understand exactly what you want. Things like "Should people need to sign in?" or "What colors do you like?" No technical questions, ever.

4. Get your app

Your coding agent builds and deploys the app, then gives you a link you can share with anyone. The whole process takes just a few minutes.

"Your trivia game is live! Share this link with your friends: https://trivia.run402.com"

After your app is live

Try it out! If you want changes, just tell your coding agent:

"Make the buttons bigger"
"Add a score counter"
"Change the colors to blue and white"
"Add a way to share results"

Your coding agent will make the changes and give you a new link with the updated app. You can iterate as many times as you want.

Good to know

Your app runs for 7 days on the free tier. If you love it, your coding agent can help you make it permanent (starting at $5/month).
Your app works on phones and computers.
Anyone with the link can use your app. No sign-up needed for your users (unless you want it).
bld402 itself is completely free. You only pay for run402 hosting if you keep your app past the trial.