User Registration

A framework-agnostic and database-agnostic user registration package for Python applications.

user-registration provides the domain and application layer for registering users while keeping framework and persistence concerns outside the core package.

Features

• Python 3.12+
• Typed Python API
• Framework independent
• Database independent
• Configurable registration behavior
• Username validation
• Email validation
• Extensible validation registry
• Password policy integration via password-validator-s
• Argon2 password hashing
• Repository abstraction
• Custom repository implementations
• Registration hooks
• Duplicate-user detection
• FastAPI adapter
• SQLAlchemy adapter
• Unit and integration tests
• Static type checking with mypy
• Linting and formatting with Ruff

Core flow

            RegistrationRequest
                 |
                 v
            RegistrationService
 +--------------------------------+
  |      |          |         |
  v      v          v         v
fields validation password repository
                   policy
                     |
                     v
                  hashing
                     |
                     v
                    User

Architecture

The core package does not depend on FastAPI, Django, Flask, SQLAlchemy, PostgreSQL, MongoDB, or any other infrastructure technology.

                       Application
                            |
                            v
                  +--------------------+
                  | RegistrationService|
                  +---------+----------+
                            |
          +-----------------+------------------+
          |                 |                  |
          v                 v                  v
   ValidationRegistry  PasswordHasher   UserRepository
                            |
                            v
                         Argon2

Basic usage

from user_registration import (
    Argon2Hasher,
    PasswordValidatorAdapter,
    RegistrationConfig,
    RegistrationRequest,
    RegistrationService,
)

service = RegistrationService(
    repository=repository,
    password_hasher=Argon2Hasher(),
    password_validator=PasswordValidatorAdapter(),
    config=RegistrationConfig(),
)

result = service.register(
    RegistrationRequest(
        username="shuvo",
        email="shuvo@example.com",
        password="StrongPassword123!",
    )
)

if result.success:
    print(result.user_id)
else:
    print(result.status, result.errors)

The application supplies the repository implementation.

Explicitly out of scope

The core does not implement login, JWT, OAuth/OIDC, sessions, MFA, RBAC, password reset, email delivery, ORM models, database connections, or HTTP routing.

Development

.venv/bin/python -m pytest -v
.venv/bin/python -m mypy src
.venv/bin/python -m ruff check src tests
.venv/bin/python -m ruff format --check src tests
.venv/bin/python -m build

License

MIT

Visit https://github.com/ShamimurRahmanShuvo/user_registration/tree/main/docs, for more details