Reference

Advanced usage

Bring your own user model, or compose the primitives into a login flow of your own design.

Custom user models#

Add your own fields to the user model. Role checks and the CLI respect it:

models.py

from datetime import datetime
from typing import Optional

from sqlmodel import SQLModel, Field

class CustomUser(SQLModel, table=True):
    __tablename__ = "user"  # keep the table name expected by the role system

    id: Optional[int] = Field(default=None, primary_key=True)
    username: str = Field(unique=True, index=True)
    email: str = Field(unique=True)
    hashed_password: str
    disabled: bool = Field(default=False)
    # your extra fields
    first_name: str = Field(default="")
    last_name: str = Field(default="")
    created_at: datetime = Field(default_factory=datetime.now)

auth = FastAuth(
    # ... other parameters ...
    user_model=CustomUser,
)

Don't import fastauth's built-in User model in the same app when using a custom one; two table models for the same table will conflict.

Custom authentication logic#

main.py

@app.post("/custom-login")
async def custom_login(
    username: str,
    password: str,
    session: Session = Depends(get_session),
):
    user = auth.authenticate_user(username, password, session=session)
    if not user:
        raise HTTPException(status_code=401, detail="Invalid credentials")

    access_token = auth.create_access_token(data={"sub": user.username})
    return {"access_token": access_token, "token_type": "bearer"}

The same primitives FastAuth's own routes use are public: auth.token_manager, auth.password_manager, auth.authenticate_user(), and RoleManager. Anything the built-in routes do, your code can do too.