GenerateRawSchema: JSON Schema Generator for Go Structs

GenerateRawSchema is a tool that generates a JSON Schema from a Go struct. The schema is built based on the tags defined in the struct fields.

Supported Tags

• description → Describes the purpose of the field to help the LLM understand its role.
• required → Marks the field as mandatory.
• enum → Specifies a set of allowed values for the field.

The field name is extracted from the json:"name" tag, and the type is inferred based on the Go data type.

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Example 1: Basic Struct Conversion

Consider the following Go struct:

type Product struct {
	ID        int     `json:"id" description:"Unique product identifier" required:"true"`
	Name      string  `json:"name" description:"Product name" required:"true"`
	Category  string  `json:"category" description:"Category of the product" enum:"Electronic,Furniture,Clothing"`
	Price     float64 `json:"price" description:"Price of the product"`
	Available bool    `json:"available" description:"Product availability" required:"true"`
}

This struct generates the following JSON Schema:

{
  "type": "object",
  "properties": {
    "id": {
      "type": "integer",
      "description": "Unique product identifier"
    },
    "name": {
      "type": "string",
      "description": "Product name"
    },
    "category": {
      "type": "string",
      "description": "Category of the product",
      "enum": ["Electronic", "Furniture", "Clothing"]
    },
    "price": {
      "type": "number",
      "description": "Price of the product"
    },
    "available": {
      "type": "boolean",
      "description": "Product availability"
    }
  },
  "required": ["id", "name", "category", "price", "available"],
  "additionalProperties": false
}

Key Features

✅ Automatic Type Inference → The type field is determined based on the Go data type.
✅ Strict Schema Enforcement → The field "additionalProperties": false ensures no extra fields can be added.
✅ Enum Support → The "category" field includes predefined values.

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Example 2: Complex Nested Structs

Go structs can also include nested objects, such as an order system:

type MenuItemSchema struct {
	ItemName string `json:"item_name" description:"Menu item name" required:"true"`
	Quantity int    `json:"quantity" description:"Quantity ordered by the user" required:"true"`
	Price    int    `json:"price" description:"Menu item price" required:"true"`
}

type UserOrderFunctionSchema struct {
	MenuItems       []MenuItemSchema `json:"menu_items" description:"List of ordered menu items" required:"true"`
	DeliveryAddress string           `json:"delivery_address" description:"Order delivery address" required:"true"`
	UserName        string           `json:"user_name" description:"User's name placing the order" required:"true"`
	PhoneNumber     string           `json:"phone_number" description:"User's phone number" required:"true"`
	PaymentMethod   string           `json:"payment_method" description:"Payment method (cash or transfer only)" required:"true" enum:"cash,transfer"`
}

This struct generates the following JSON Schema:

{
  "type": "object",
  "properties": {
    "menu_items": {
      "type": "array",
      "description": "List of ordered menu items",
      "items": {
        "type": "object",
        "properties": {
          "item_name": {
            "type": "string",
            "description": "Menu item name"
          },
          "quantity": {
            "type": "integer",
            "description": "Quantity ordered by the user"
          },
          "price": {
            "type": "integer",
            "description": "Menu item price"
          }
        },
        "required": ["item_name", "quantity", "price"],
        "additionalProperties": false
      }
    },
    "delivery_address": {
      "type": "string",
      "description": "Order delivery address"
    },
    "user_name": {
      "type": "string",
      "description": "User's name placing the order"
    },
    "phone_number": {
      "type": "string",
      "description": "User's phone number"
    },
    "payment_method": {
      "type": "string",
      "description": "Payment method (cash or transfer only)",
      "enum": ["cash", "transfer"]
    }
  },
  "required": ["menu_items", "delivery_address", "user_name", "phone_number", "payment_method"],
  "additionalProperties": false
}

Understanding the Nested Structure

• menu_items is an array of objects, each containing:

  • item_name (string)
  • quantity (integer)
  • price (integer)

• "additionalProperties": false is automatically applied to all objects to prevent extra fields.

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Limitations & Further Exploration

🔹 This tool supports a subset of JSON Schema features and may not handle very complex schemas.
🔹 For advanced use cases, consider using invopop/jsonschema, a Go library for more powerful JSON Schema generation.
🔹 For deeper understanding, refer to the official JSON Schema documentation.