Schema Gen Documentation¶

Welcome to Schema Gen - the schema generator for Python!

Schema Gen eliminates schema duplication in Python projects by providing a single source of truth for your data models. Define your schemas once using Python type annotations, then generate Pydantic models, SQLAlchemy tables, and other formats automatically.

Getting Started - Installation and your first schema
Schema Format - Complete field types and constraints reference
CLI Reference - All command-line tools
Configuration - Project configuration options
Examples - Real-world usage examples
API Reference - Python API documentation

Why Schema Gen?¶

The Problem¶

In modern Python applications, especially FastAPI projects, you often need to maintain: - Pydantic models for API request/response validation - SQLAlchemy models for database operations - Data processing schemas for analytics pipelines - Multiple variants of the same model for different use cases

This leads to code duplication, maintenance burden, and version skew.

The Solution¶

Schema Gen provides a single source of truth approach: - ✅ Define once - write your schema definition in one place - ✅ Generate everywhere - automatically create all required variants - ✅ Stay in sync - generated code is always up-to-date - ✅ Version controlled - generated files are committed to git - ✅ Type safe - full IDE support with type hints and validation

Features¶

Current Features¶

Pydantic Generation - Full Pydantic v2 models with validation
Schema Variants - Multiple model variants from single definition
Rich Validation - String, numeric, format, and custom constraints
CLI Tools - Complete command-line interface
File Watching - Auto-regeneration during development
Pre-commit Hooks - Automatic generation in git workflow
Type Safety - Full IDE support and static type checking
Breaking Change Detection - Detect breaking schema changes before merge with schema-gen diff

Planned Features¶

SQLAlchemy Generation - Database models and migrations
Pathway Generation - Data processing schemas
GraphQL Support - Schema and resolver generation
OpenAPI Enhancement - Rich API documentation
Custom Generators - Plugin system for custom formats

Get Started¶

Ready to eliminate schema duplication in your project? Head over to Getting Started to begin!