✦ EqFix — AI Equation Repair Tool

Paste any broken or garbled math from an AI chat, PDF, or copied text — get back clean LaTeX, MathML, and Unicode with a live rendered preview.

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🔍 What It Does

When you copy equations from AI responses, PDFs, or plain-text sources, the formatting is usually broken — Greek letters become question marks, fractions collapse into ASCII slashes, and subscripts vanish. EqFix sends the raw text to Claude AI and returns:

• ✅ Valid LaTeX (inline $...$ and display $$...$$ ready)
• ✅ Well-formed MathML markup
• ✅ Readable Unicode math (∫ ∑ √ × ≤ …)
• ✅ A live rendered preview via MathJax
• ✅ A plain-English explanation of what the equation means

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✨ Features

Feature	Details
🤖 AI-powered	Uses Claude Sonnet via the Anthropic API
🎨 Dark & Light theme	Toggle button with preference saved to localStorage
📋 One-click copy	Copy LaTeX, MathML, Unicode, inline, or display format
👁️ Live preview	MathJax renders the equation so you can verify it
⌨️ Keyboard shortcut	Ctrl+Enter / Cmd+Enter to fix
💡 6 example equations	From E=mc² to Maxwell's equations
📱 Responsive	Works on desktop and mobile
🔒 No data stored	Everything is processed in-browser per request

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🚀 Live Demo

👉 eqfix.Mustofa-statcn.github.io

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🛠️ Tech Stack

• Vanilla HTML/CSS/JS — zero build step, zero dependencies to install
• Anthropic Claude API (claude-sonnet-4-20250514) — equation parsing & conversion
• MathJax 3 — browser-side LaTeX rendering
• Google Fonts — DM Serif Display, DM Sans, Fira Code

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📦 Project Structure

eqfix/
├── index.html      ← The entire app (single file)
└── README.md       ← This file

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⚡ Getting Started Locally

No build tools needed. Just open the file:

git clone https://github.com/your-username/eqfix.git
cd eqfix
open index.html        # macOS
# or
start index.html       # Windows
# or
xdg-open index.html    # Linux

Note: The Anthropic API key is injected automatically when served from Claude.ai. For standalone hosting, see API Key Setup below.

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🔑 API Key Setup

The app calls the Anthropic API directly from the browser. To host it yourself:

1. Get an API key from console.anthropic.com
2. Open index.html and find the fetch call (around line 690)
3. Add your key to the headers:

headers: {
  "Content-Type": "application/json",
  "x-api-key": "sk-ant-YOUR_KEY_HERE",      // ← add this
  "anthropic-version": "2023-06-01",          // ← add this
  "anthropic-dangerous-direct-browser-access": "true"  // required for browser
},

⚠️ Security note: Embedding an API key in a public HTML file exposes it to anyone who views the source. For production use, proxy the API call through a serverless function (Cloudflare Workers, Vercel Edge, etc.) that keeps the key server-side.

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🌐 Deploying to GitHub Pages

Step 1 — Create the repository

1. Go to github.com/new
2. Name it eqfix (or anything you like)
3. Set visibility to Public
4. Leave "Initialize with README" unchecked (you have your own)
5. Click Create repository

Step 2 — Push your files

# In your project folder:
git init
git add index.html README.md
git commit -m "Initial commit — EqFix equation repair tool"
git branch -M main
git remote add origin https://github.com/YOUR_USERNAME/eqfix.git
git push -u origin main

Step 3 — Enable GitHub Pages

1. In your repo, go to Settings → Pages
2. Under Source, select Deploy from a branch
3. Choose branch: main, folder: / (root)
4. Click Save
5. Wait ~60 seconds, then visit:

https://Mustofa-statcn.github.io/eqfix/

GitHub will show the live URL at the top of the Pages settings once it's deployed.

Step 4 — Update the README link

Edit README.md and replace the placeholder demo URL with your real GitHub Pages URL, then:

git add README.md
git commit -m "Update live demo link"
git push

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🔄 Updating the App

After making changes to index.html:

git add index.html
git commit -m "Your description of the change"
git push

GitHub Pages redeploys automatically within about a minute.

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🧪 Example Inputs

Broken input	What EqFix returns
E = mc^2	E = mc^{2}
x = (-b ± √(b²-4ac)) / 2a	x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
∫_{-∞}^{∞} e^(-x²) dx = √π	\int_{-\infty}^{\infty} e^{-x^2}\,dx = \sqrt{\pi}
∇ × B = μ₀J + μ₀ε₀ ∂E/∂t	\nabla \times \mathbf{B} = \mu_0 \mathbf{J} + \mu_0 \varepsilon_0 \frac{\partial \mathbf{E}}{\partial t}

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🤝 Contributing

Pull requests are welcome! To contribute:

1. Fork the repo
2. Create a branch: git checkout -b feature/my-improvement
3. Make your changes to index.html
4. Commit: git commit -m "Add my improvement"
5. Push: git push origin feature/my-improvement
6. Open a Pull Request on GitHub

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📄 License

MIT — do whatever you want with it. Attribution appreciated but not required.

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🙏 Credits

• Built with Claude by Anthropic
• Math rendering by MathJax
• Fonts by Google Fonts