json-schema

name	json-schema
description	Generate and validate JSON Schema definitions. Use when asked to create schemas, validate JSON structure, or document API payloads.
version	1.0.0

JSON Schema Generator

Overview

Creates JSON Schema definitions for data validation and API documentation.

Instructions

When generating JSON Schema:

1. Analyze the data structure or requirements
2. Determine types for each field (string, number, object, array, etc.)
3. Add constraints: required fields, patterns, min/max values
4. Include descriptions for documentation
5. Set appropriate $schema version (draft-07 recommended)

Schema Components

Basic Types

• string - Text values
• number / integer - Numeric values
• boolean - True/false
• object - Nested structures
• array - Lists of items
• null - Null values

Common Constraints

• required - Mandatory fields
• minLength / maxLength - String length
• minimum / maximum - Number bounds
• pattern - Regex validation
• enum - Allowed values
• format - Semantic formats (email, uri, date-time)

Examples

Example: User Schema

Input: "Create a schema for a user with name, email, age, and optional phone"

Output:

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "User",
  "type": "object",
  "required": ["name", "email", "age"],
  "properties": {
    "name": {
      "type": "string",
      "minLength": 1,
      "maxLength": 100,
      "description": "User's full name"
    },
    "email": {
      "type": "string",
      "format": "email",
      "description": "User's email address"
    },
    "age": {
      "type": "integer",
      "minimum": 0,
      "maximum": 150,
      "description": "User's age in years"
    },
    "phone": {
      "type": "string",
      "pattern": "^\\+?[1-9]\\d{1,14}$",
      "description": "Optional phone number in E.164 format"
    }
  },
  "additionalProperties": false
}

Guidelines

Do

• Always include $schema declaration
• Add descriptions for all properties
• Use additionalProperties: false for strict validation
• Prefer specific formats over loose patterns
• Use required array for mandatory fields

Don't

• Use overly permissive types (avoid {} or true)
• Skip validation constraints on user input
• Mix draft versions in same schema
• Forget to handle nullable fields explicitly