Python FastAPI Agent
Agent for Python FastAPI backends with SQLAlchemy, Pydantic validation, async patterns, and production-ready project structure.
A purpose-built agent configuration for Python backend development with FastAPI. This template teaches your AI assistant the conventions that matter for building fast, type-safe, and well-structured APIs — from request validation to database access and async concurrency.
What’s included
- FastAPI project structure — Router-based organization with dependency injection, versioned API prefixes, and a clean separation between routes, services, and data access layers.
- Pydantic models — Request and response schemas with strict validation, custom validators, and a clear naming convention (
CreateUserRequest,UserResponse) that keeps your API contract explicit. - SQLAlchemy async — Async session management, repository pattern for data access, Alembic migrations, and relationship loading strategies. The agent avoids the common pitfalls of lazy loading in async contexts.
- Async patterns — Proper use of
async defvsdeffor route handlers, background tasks withasyncio, and connection pooling best practices. The agent understands when blocking calls need to be offloaded to a thread pool. - Error handling — Consistent exception hierarchy with custom HTTP exception handlers, structured error responses, and proper status code usage across the application.
- Authentication and security — OAuth2 with JWT tokens, dependency-based permission checks, CORS configuration, and rate limiting patterns.
- Testing — pytest with
httpx.AsyncClientfor integration tests, factory-based fixtures, and database transaction rollback between tests for isolation.
Who it’s for
Backend developers building REST APIs with Python who want their AI assistant to produce idiomatic, production-grade FastAPI code. This template is a strong fit for microservices, internal APIs, and data-heavy backends where type safety and performance both matter.
Skills at a glance
Covers endpoint design, database modeling, authentication flows, background job patterns, structured logging, Docker containerization, and OpenAPI documentation customization.
How to use
- Click Use Template to open it in the spaget builder
- Tune the database, auth, and project structure rules to your needs
- Export to Claude Code, Cursor, or Copilot
- Add the configuration file to your project root
Start building your FastAPI agent now. Open this template in spaget and customize it for your stack.