fastapi-patternslisted

FastAPI project structure, directory organization, and file naming conventions. Use when creating new routes, services, components, or any new directory/file in a FastAPI project. Defines what lives where and why — the structural DNA of the project. Do NOT use for general-purpose Python conventions outside a FastAPI project, or for protocol-specific streaming formats (e.g. typed event schemas) that define their own SSE termination/error conventions — this skill's generic SSE rules apply only when no such protocol is in play.
RahulDas-dev/skill_builder · ★ 0 · API & Backend · score 61

Install: claude install-skill RahulDas-dev/skill_builder

# FastAPI Project Structure & Patterns ## When to Use This Skill * Scaffolding a new route, service, component, config concern, or startup step in a FastAPI project * Deciding which directory/file a piece of logic belongs in (`routes/` vs `services/` vs `db/` vs `startops/`) * Reviewing whether an existing FastAPI project follows consistent structure and naming * Adding SSE streaming endpoints, dependency injection, or error-handling to a route ## Dependencies | Package | Role | Required | | --- | --- | --- | | `fastapi` | Web framework — routing, DI, `StreamingResponse` | Yes | | `pydantic` v2 | `BaseModel` request/response models, `Field`, `alias_generators.to_camel` | Yes | | `pydantic-settings` | `BaseSettings` config classes (see `references/configs.md`) | Yes | | `sqlalchemy` (async, 2.0-style `Mapped`/`mapped_column`) | ORM layer (`db/`) | Yes, if using a database | | `asyncpg` / `aiosqlite` | Async DB drivers for Postgres / SQLite respectively | Yes, matching your `DB_TYPE` | | `python-dotenv` | Loads the `.config` env file at startup (`startops/set_env.py`) | Yes | | `sse-starlette` | Alternative SSE response wrapper (see `references/routes.md`) | Optional | | `uvicorn` | ASGI server to run the app | Yes, for local/dev running | This skill documents *conventions* on top of these libraries, not the libraries themselves — see each library's own docs for API details. ## Project Layout ``` <package>/ ├── app.py # FastAPI app factory + lifesp