fastgen

A nest cli-style module manager for FastAPI: it scaffolds a minimal, zero-config module skeleton (entity, service, router, shared session dependency) and keeps a module registry so AI agents and developers can see the project structure at a glance. Fill in the business logic yourself.

Install

pip install fastgen-cli
# or
uv add fastgen-cli

Usage

fastgen --help

# Scaffold a feature module and register it
fastgen make module user

# List registered modules and their boundaries
fastgen list

Both commands support --dir <root> (project root, defaults to cwd), --dry-run (preview without writing) and --force (overwrite existing skeleton files).

Running fastgen make module <feature> generates:

app/
├── core/                        # auto-created on first use
│   ├── config.py                # pydantic-settings Settings (DATABASE_URL in .env)
│   └── database.py              # Base (AsyncAttrs), async engine, get_session dependency
└── modules/
    ├── __init__.py              # module registry (auto-maintained, do not edit)
    └── user/
        ├── __init__.py          # re-exports router
        ├── schemas.py           # Pydantic entity skeleton: class User(BaseModel): pass
        ├── service.py           # business layer boundary: class UserService
        └── router.py            # APIRouter + SessionDep (Annotated[AsyncSession, Depends(get_session)])

Existing code is never overwritten: app/core/config.py / database.py are only generated when missing or empty.

Conventions (fixed)

• Modules live in app/modules/<feature>/, one business unit per folder.
• The router exposes prefix="/<plural>" and tags; the shared session dependency is imported from app.core.database.
• app/modules/__init__.py is a fastgen-maintained registry (modules: dict[str, str]) mapping module name to import path; fastgen list reads it (and each module's docstring) to show the whole project.

Roadmap

• Phase 1: make module (schemas + service skeleton) ✅
• Phase 2: module registry + fastgen list ✅
• Phase 3: make resource (full CRUD router), Alembic migration hints