schema-to-erd

Convert JSON Schema (Draft 2020-12) into simple, human-friendly ERD diagrams.

This tool transforms structured JSON Schema definitions into clear entity-relationship diagrams — making them easier to understand for both technical and non-technical users.

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✨ Features

• 🔄 Convert JSON Schema → ERD diagram
• 🧠 Simplified visual output (focused on clarity)
• 📦 Supports standard JSON Schema format
• 🎨 Export diagrams as PNG (via Graphviz)
• 🧩 CLI + Python API support

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📦 Installation

pip install schema-to-erd

⚠️ Requires Graphviz installed:

Mac

brew install graphviz

Ubuntu

sudo apt install graphviz

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🚀 Quick Start (CLI)

schema-to-erd --input schema.json

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⚙️ CLI Options

schema-to-erd --input schema.json --out-file product --format png

Option	Description
--input	Path to JSON schema file (required)
--out-file	Output file name
--format	Output format (default: png)

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🧪 Example

Input (product.schema.json)

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Product",
  "type": "object",
  "properties": {
    "productId": {
      "type": "integer"
    },
    "productName": {
      "type": "string"
    }
  }
}

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Command

schema-to-erd --input product.schema.json --format png

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Output

The tool generates a diagram with:

• Entity: Product

• Attributes:

  • productId (integer)
  • productName (string)

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🐍 Python Usage

from schema_to_erd import build_erd_from_schema

build_erd_from_schema(
    "product.schema.json",
    "product",
    "png"
)

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📁 Output Behaviour

schema-to-erd --input path/to/product.schema.json

👉 Output:

product.png

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🧠 How It Works

• JSON Schema title → Entity name
• properties → Attributes
• Nested objects / references → Relationships

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🛠️ Development

git clone https://github.com/khalsz/schema-to-ERD.git
cd schema-to-ERD
pip install -e .

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🧪 Testing

pytest

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📄 License

MIT License

🤝 Contributing

Contributions are welcome!

• Open issues
• Suggest improvements
• Submit pull requests

👤 Author

Built by Khalsz