Python Backend Expert

What it does

This skill provides expert assistance with Python backend development specifically within FastAPI applications. It helps with tasks like defining API endpoints, creating data schemas using Pydantic v2, building SQLAlchemy 2.0 models and queries, implementing data access layers (repository pattern), and managing business logic. The skill is designed to streamline the creation and maintenance of backend services and APIs.

When to use it

• Developing or modifying FastAPI route handlers (endpoints).
• Defining Pydantic v2 schemas for request and response bodies.
• Creating SQLAlchemy 2.0 async models, queries, and relationships.
• Implementing the repository pattern for data access logic.
• Writing service layer business logic within your application.

Key capabilities

• FastAPI route handler development
• Pydantic v2 schema definition and updates
• SQLAlchemy 2.0 async model creation and querying
• Repository pattern implementation
• Service layer business logic writing
• Alembic migration generation and execution
• Dependency injection using Depends()

Example prompts

• "Generate a FastAPI route handler for creating a new user, including Pydantic schema validation."
• "Write an SQLAlchemy 2.0 model for a 'Product' with attributes like name, description, and price."
• "Implement the repository pattern for accessing users from a database."

Tips & gotchas

• This skill is not intended for writing tests (use pytest-patterns instead).
• Avoid using it for FastAPI framework mechanics such as middleware or CORS configuration; use fastapi-patterns for those tasks.
• The skill assumes a project structure similar to the example provided in the documentation, including directories like app/core, app/models, and app/repositories.