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Custom Auth Model

Use your own user model instead of the built-in admin_users table. This is the recommended pattern when your project already has a User model (SQLAlchemy, SQLModel, or anything that satisfies AdminUserProtocol).

Why use a custom auth model

  • You already have a User model with your schema, password hashing, and email-verification flow. Reusing it avoids two parallel user tables.
  • Your User.id may be a UUID, ULID, or String(36) — the admin tables adapt their user_id columns to match.
  • Roles, permissions, and audit log records reference your real user IDs.

Minimal example

import uuid
from typing import Optional

from fastapi import FastAPI
from sqlalchemy import Column, ForeignKey, Integer, String
from sqlalchemy.orm import DeclarativeBase, relationship
from sqlalchemy.types import Uuid

from fastapi_admin_kit import Admin, DatabaseConfig, DatabaseType
from fastapi_admin_kit.auth.mixins import AuthModelMixin


class Base(DeclarativeBase):
    pass


class User(AuthModelMixin, Base):
    __tablename__ = "users"

    id = Column(Uuid, primary_key=True, default=uuid.uuid4)
    email = Column(String(255), unique=True, nullable=False, index=True)
    hashed_password = Column(String(255), nullable=False)
    name = Column(String(255), nullable=True)

    # AuthModelMixin provides the rest of the protocol surface
    # (is_active, is_superuser, role_ids, verify_password, etc.).


app = FastAPI()
admin = Admin(
    app=app,
    base=Base,
    database_config=DatabaseConfig(
        db_type=DatabaseType.POSTGRESQL,
        url="postgresql+asyncpg://user:pass@localhost/app",
    ),
    secret_key="change-me-to-32-chars-or-more-please",
    auth_model=User,
)

When auth_model= is supplied:

  1. The built-in admin_users and admin_user_roles tables are not created. Your User table is the single source of truth.
  2. The built-in log-pattern user_id columns (admin_audit_log.user_id, admin_user_permissions.user_id, admin_refresh_tokens.user_id, etc.) are retyped to match your User.id type — e.g. Uuid if your User.id is a Uuid.
  3. The built-in UserAdmin CRUD view is not registered. Register your own UserAdmin subclass against your model if you want it in the sidebar.

Lifespan setup

The recommended pattern is to call admin.create_tables() from your lifespan instead of touching AdminBase.metadata directly. The package will skip the built-in user tables and let your project's metadata own them.

from contextlib import asynccontextmanager
from fastapi import FastAPI
from sqlmodel import SQLModel  # or your ORM of choice

@asynccontextmanager
async def lifespan(app: FastAPI):
    # 1. Create your project's tables first
    async with engine.begin() as conn:
        await conn.run_sync(SQLModel.metadata.create_all)

    # 2. Create the admin tables (built-in user tables are skipped
    #    because auth_model=User is configured)
    await admin.create_tables()

    # 3. Wire up routes, middleware, templates
    await admin.setup(app)

    yield

Do not call AdminBase.metadata.create_all directly. It bypasses the custom-auth_model logic and will create the default admin_users / admin_user_roles tables even when you supplied your own user model. Always go through admin.create_tables() or admin.setup().

What you keep

Even with a custom auth_model, the admin still manages these tables:

  • admin_roles and admin_permissions (RBAC)
  • admin_user_permissions (per-user permission overrides)
  • admin_refresh_tokens (session storage)
  • admin_user_totp (2FA secrets)
  • admin_audit_log (change history with user_id and user_email)
  • admin_notifications and friends (when notifications are enabled)
  • admin_ai_* (when AI is enabled)

What you bring

Your auth_model must satisfy AdminUserProtocol (validated at Admin() construction time):

Attribute Type Notes
id any The PK type — int, UUID, etc.
email str Used as the login identifier
is_active bool Inactive users cannot log in
is_superuser bool Bypasses all RBAC checks
hashed_password str bcrypt / argon2 hash
role_ids list[int] Property that returns role IDs
roles relationship M2M to Role model
verify_password(plain) method Returns bool

fastapi_admin_kit.auth.mixins.AuthModelMixin provides all of the above for SQLAlchemy declarative models — inherit from it to get is_active, is_superuser, role_ids, and password helpers for free.

Troubleshooting

'NoneType' object has no attribute '_run_ddl_visitor'

You called AdminBase.metadata.create_all directly, or you constructed Admin() without an engine and without a database_config. Pass one of:

admin = Admin(
    engine=engine,                  # explicit engine
    # or
    database_config=DatabaseConfig(...),  # lazy engine from URL
)

If you want the admin to skip table creation entirely (e.g. you manage schema with Alembic), pass use_alembic=True.

admin_users table keeps being created

Make sure you're using admin.create_tables() or admin.setup(), not AdminBase.metadata.create_all. The package never mutates the shared AdminBase.metadata (its FacadeDict is immutable); it filters the excluded tables only at create_all time, and only via the public Admin API.

TypeError: Object of type UUID is not JSON serializable on login

The session cookie is signed via itsdangerous, whose default JSON encoder doesn't know about UUID. The admin's SignedCookieSessionBackend registers a default= handler that converts UUID → str, datetime → ISO string, Decimal → str, and set/frozenset → list. This covers every payload type a typical auth_model exposes (user.id, iat, optional exp), so a UUID PK works out of the box.

If you replace the session backend with a custom one, make sure your encoder handles the same set of types — or coerce user.id to str before stuffing it into the payload.