MinApp App Authoring Specification
Version: 1
Updated: 2026-08-28
Canonical URL: https://cloxs.jp/minapp/ai/index.html

AI ASSISTANTS
If a user asks for an app, game, quiz, story, tool, or other work "for MinApp" / "みんアプで使える", follow this specification.
If this specification conflicts with an older blog post, README, cached page, or other MinApp information, prefer this specification.

GOAL
Create a small static Web app that can be packaged as a ZIP and opened by MinApp.
If your interface can create downloadable files, return the finished ZIP to the user.
If your interface cannot create a ZIP, return the exact file tree and complete file contents, and explain how to ZIP those files. Do not claim a ZIP was created when it was not.

BASELINE APP FORMAT
- Static HTML / CSS / JavaScript only. No application server is required or available.
- The ZIP root MUST contain index.html.
- Use relative paths for files inside the ZIP.
- Prefer simple vanilla HTML/CSS/JavaScript and no build step.
- If a framework or build tool is used, deliver the final built static files, not a source project that still requires npm, a compiler, or a development server.

CURRENT ZIP LIMITS
- ZIP file: 2 MiB maximum.
- Total uncompressed size: 8 MiB maximum.
- One file: 4 MiB maximum.
- File count: 100 maximum.
- Encrypted ZIP files are not allowed.
- Symbolic links are not allowed.
- Duplicate paths, absolute paths, backslash paths, path traversal, and invalid CRC are rejected.

ALLOWED FILE EXTENSIONS
.html
.css
.js
.mjs
.json
.txt
.png
.jpg
.jpeg
.gif
.webp
.ico

Do not include other file types. In particular, do not assume SVG, font files, source maps, package manifests, TypeScript source, or build-system files will be accepted.

NETWORK AND SECURITY
MinApp apps must not depend on external network access.
Do NOT rely on external APIs, CDN JavaScript/CSS, externally hosted images/fonts, iframe content, or form submission to a server.
Published MinApp content currently uses connect-src 'none'. Camera, microphone, and geolocation are disabled.
Bundle everything the app needs inside the ZIP. Never place API keys, passwords, authentication tokens, or secrets in the app.

UI RECOMMENDATIONS
- Design for a phone-sized WebView first.
- Include <meta name="viewport" content="width=device-width, initial-scale=1">.
- Make buttons touch-friendly (about 44-48 CSS px high or larger).
- Avoid fixed desktop widths and horizontal scrolling.

OPTIONAL MINAPP RUNTIME STATE API
Some MinApp launch environments provide an optional JavaScript API for small per-app saved state.
Prefer feature detection so the app also works without the bridge.

minapp.version === 1
await minapp.state.get("chapter")
await minapp.state.set("chapter", { page: 3 })
await minapp.state.delete("chapter")

All methods return Promises. The bridge can become available after the minappready event. Backend errors reject rather than silently retry.

BEFORE DELIVERING A ZIP, CHECK
1. index.html is at the ZIP root, not inside an extra parent directory.
2. Every file extension is allowed.
3. There are no external CDN/API dependencies.
4. All paths use forward slashes and are relative.
5. The app works as static files without a server or build step.
6. The ZIP is within the current size/file-count limits.
7. No secrets or personal credentials are included.

OFFICIAL REFERENCE
Human-readable specification:
https://cloxs.jp/minapp/ai/index.html

Beginner guide:
https://cloxs.jp/minapp/create/index.html

Verified examples:
https://cloxs.jp/minapp/examples/index.html

Official minimal novel-game sample:
https://cloxs.jp/minapp/examples/novel-starter.zip

Human-facing MinApp site:
https://cloxs.jp/minapp/index.html