JSON Schema is a vocabulary for annotating and validating JSON documents. It defines the expected structure of a JSON object — field names, data types, required fields, and constraints. JSON Schema is used in API documentation (OpenAPI/Swagger), form validation, data pipeline contracts, and configuration validation.

InfraHub's SQL to JSON Schema converter bridges the gap between relational database design and modern API development by automatically generating a valid JSON Schema draft from a SQL CREATE TABLE statement.

The converter parses SQL CREATE TABLE statements using a custom SQL grammar parser. It extracts column names, SQL data types (VARCHAR, INT, BOOLEAN, TIMESTAMP, etc.), NOT NULL constraints, and DEFAULT values. Each SQL column is mapped to the corresponding JSON Schema type: VARCHAR → string, INT → integer, BOOLEAN → boolean, TIMESTAMP → string with format: date-time. NOT NULL columns without defaults are added to the required array.

Backend developers bootstrap API request/response schemas from existing database tables. API designers create OpenAPI component schemas without writing them from scratch. Database-first teams generate input validation schemas for Node.js (Joi/Zod) or Python (Pydantic) from their PostgreSQL or MySQL table definitions. Data engineers define schema contracts for Kafka topics, Avro schemas, or data lake table definitions based on existing SQL models.