Learn how to create and publish apps with AI.
No programming experience needed — this page will get you started.
Just describe the app you want in plain language, and AI will generate the code for you. Upload it to Blue and your web app is published instantly.
Choose the method that works best for you.
Everything happens inside Blue. Enter a prompt and publish instantly. Start here if you're not sure.
Use ChatGPT, Claude, or Gemini to generate code, then upload to Blue.
Claude Code or Codex handle everything from code generation to deploying on Blue.
Compare the three methods and choose the one that fits your needs.
| Method | Features | Best for |
|---|---|---|
| AI Build Recommended | Everything inside Blue. Enter a prompt, publish instantly | Quick experiments · Simple apps |
| Chat AI (ChatGPT, Claude, etc.) | Generate code through conversation, upload to Blue to publish | Beginners · No special tools needed |
| AI Agents (Claude Code, Codex) | Build advanced apps, auto-deploy via API key | Those who want more sophisticated apps |
Use your favorite chat AI — ChatGPT, Claude, Gemini, or others — to generate app code, then upload it to Blue. No special tools to install; a browser is all you need.
Open your preferred chat AI and describe the app you want to build.
Save the generated code as a file (e.g. index.html). If there are multiple files, put them in a folder and compress it into a ZIP. Even a single file needs to be zipped — just right-click and choose "Compress" in your file manager.
Log in to Blue, open the console (/console), and upload your ZIP file. Your app is published with a URL.
Note: Chat AI cannot deploy directly to Blue, so you upload the code manually. However, this is the most accessible method — no installation required, and you can use whichever AI you already know.
Claude Code (Anthropic) and Codex (OpenAI) are AI tools that can build your app and publish it to Blue for you. Best for more advanced or complex applications.
Launch the Claude Code or Codex desktop app.
Describe the app you want in natural language. The AI will create the files automatically.
Publish the generated code to Blue. There are two ways:
Option A: Upload a ZIP from the console (/console) — same as the Chat AI method.
Option B: Auto-deploy via API key — give the AI agent your Blue deploy key and it will handle deployment automatically.
For API deployment details, see the AI-Ready documentation.
The most casual way to create an app — everything happens inside Blue. Just enter a prompt and publish. Currently best suited for simple apps (single-page HTML, etc.).
Log in to Blue and navigate to the AI Build page. You'll see templates and a prompt input field.
Type a description of the app you want. Works in English or Japanese.
Once the code is generated, click "Deploy". Your app is published with a URL.
The Console's “Showcase image” and “Showcase icon” are only for listings on Blue's home page and Showcase. Your app owns its browser-tab favicon and its Open Graph and social-sharing metadata.
Upload images through an AI Build attachment or Work assets (Asset Library), then tell AI Build which file to use and why. Include favicon files in the app bundle and reference them from the HTML <head>. For Open Graph, use a 1200×630 image where possible and set og:image to an absolute URL that is reachable from the published app.
Before publishing, check og:title, og:description, og:url, og:image, and twitter:card. Do not declare an image URL unless that asset exists.
<link rel="icon" type="image/png" href="/assets/favicon.png">
<link rel="apple-touch-icon" href="/assets/apple-touch-icon.png">
<meta property="og:type" content="website">
<meta property="og:title" content="App name">
<meta property="og:description" content="App description">
<meta property="og:url" content="https://example.com/">
<meta property="og:image" content="https://example.com/assets/ogp.jpg">
<meta property="og:image:width" content="1200">
<meta property="og:image:height" content="630">
<meta name="twitter:card" content="summary_large_image">
<meta name="twitter:image" content="https://example.com/assets/ogp.jpg">Blue supports app secrets while keeping secret values out of prompts, logs, and public URLs.
Store API keys in Settings > Secrets, then tell AI Build which variable name to use. The running app can read it with os.environ["KEY"] in Python or process.env.KEY in Node.js.
If a ZIP contains a root .env, .env.local, .env.development, or .env.production, Blue imports valid keys as app environment variables during upload. Runtime-control keys such as PORT, HOST, PATH, NODE_OPTIONS, and PYTHONPATH remain managed by Blue.
Use simple KEY=value or export KEY=value lines. Blue accepts up to 50 app environment variables and reads each root .env file up to 50 KB; unsupported names, platform-managed keys, and runtime startup keys are skipped.
Dotfiles such as .env are blocked at the app proxy. Deploy warnings may mention that a sensitive file was detected, but secret values are not shown in logs or warnings.
Recommended: use Settings > Secrets for long-lived API keys. Use a ZIP .env when moving an existing local app to Blue or testing a small integration.