Implement fintech payment service backend with FastAPI and SQLite

- Set up project structure with FastAPI
- Implement user and account management
- Add send and receive money functionality
- Set up transaction processing system
- Add JWT authentication
- Configure SQLAlchemy with SQLite
- Set up Alembic for database migrations
- Create comprehensive API documentation

README.md

@@ -1,3 +1,186 @@
-# FastAPI Application
+# Fintech Payment Service
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A FastAPI backend for fintech payment services, providing APIs for users, accounts, and money transfer operations.
+
+## Features
+
+- **User Management**: Create and manage user accounts
+- **Account Management**: Create and manage financial accounts
+- **Transaction Processing**:
+  - Send money to external accounts
+  - Receive money from external sources
+  - Make internal transfers between accounts
+  - View transaction history
+- **Security**: JWT authentication for secure API access
+
+## Tech Stack
+
+- **Framework**: FastAPI
+- **Database**: SQLite
+- **ORM**: SQLAlchemy
+- **Migrations**: Alembic
+- **Authentication**: JWT (JSON Web Tokens)
+- **Password Hashing**: Bcrypt
+
+## API Endpoints
+
+### Authentication
+
+- `POST /api/v1/login/access-token` - Get access token
+
+### Users
+
+- `POST /api/v1/users/` - Create a new user
+- `GET /api/v1/users/me` - Get current user info
+- `PUT /api/v1/users/me` - Update current user info
+- `GET /api/v1/users/{user_id}` - Get user by ID
+
+### Accounts
+
+- `GET /api/v1/accounts/` - List user accounts
+- `POST /api/v1/accounts/` - Create a new account
+- `GET /api/v1/accounts/{account_id}` - Get account details
+- `PUT /api/v1/accounts/{account_id}` - Update account details
+- `DELETE /api/v1/accounts/{account_id}` - Delete an account
+
+### Transactions
+
+- `GET /api/v1/transactions/` - List user transactions
+- `GET /api/v1/transactions/account/{account_id}` - List account transactions
+- `POST /api/v1/transactions/deposit` - Create a deposit
+- `POST /api/v1/transactions/withdrawal` - Create a withdrawal
+- `POST /api/v1/transactions/transfer` - Transfer between accounts
+- `POST /api/v1/transactions/receive` - Receive money from external source
+- `POST /api/v1/transactions/send` - Send money to external destination
+- `GET /api/v1/transactions/{transaction_id}` - Get transaction details
+
+### Health Check
+
+- `GET /api/v1/health` - Check API health
+
+## Setup Instructions
+
+### Prerequisites
+
+- Python 3.8+
+- pip
+
+### Installation
+
+1. Clone the repository:
+   ```bash
+   git clone <repository-url>
+   cd fintechpaymentservice
+   ```
+
+2. Install dependencies:
+   ```bash
+   pip install -r requirements.txt
+   ```
+
+3. Set up environment variables:
+   ```bash
+   # Create a .env file with the following variables
+   SECRET_KEY=your_secret_key_here
+   ALGORITHM=HS256
+   ACCESS_TOKEN_EXPIRE_MINUTES=30
+   ```
+
+4. Run database migrations:
+   ```bash
+   alembic upgrade head
+   ```
+
+5. Start the server:
+   ```bash
+   uvicorn main:app --reload
+   ```
+
+6. Access the API documentation:
+   - Swagger UI: http://localhost:8000/docs
+   - ReDoc: http://localhost:8000/redoc
+
+## Usage Examples
+
+### Create a User
+
+```bash
+curl -X POST "http://localhost:8000/api/v1/users/" \
+  -H "Content-Type: application/json" \
+  -d '{
+    "email": "user@example.com",
+    "first_name": "John",
+    "last_name": "Doe",
+    "password": "securepassword"
+  }'
+```
+
+### Get Access Token
+
+```bash
+curl -X POST "http://localhost:8000/api/v1/login/access-token" \
+  -H "Content-Type: application/x-www-form-urlencoded" \
+  -d "username=user@example.com&password=securepassword"
+```
+
+### Create an Account
+
+```bash
+curl -X POST "http://localhost:8000/api/v1/accounts/" \
+  -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
+  -H "Content-Type: application/json" \
+  -d '{
+    "account_type": "savings",
+    "currency": "USD"
+  }'
+```
+
+### Receive Money
+
+```bash
+curl -X POST "http://localhost:8000/api/v1/transactions/receive" \
+  -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
+  -H "Content-Type: application/json" \
+  -d '{
+    "receiver_account_id": 1,
+    "external_sender_info": "Bank XYZ - Account 12345",
+    "amount": 500.00,
+    "currency": "USD",
+    "description": "Salary payment"
+  }'
+```
+
+### Send Money
+
+```bash
+curl -X POST "http://localhost:8000/api/v1/transactions/send" \
+  -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
+  -H "Content-Type: application/json" \
+  -d '{
+    "sender_account_id": 1,
+    "external_receiver_info": "Bank ABC - Account 67890",
+    "amount": 100.00,
+    "currency": "USD",
+    "description": "Utility bill payment"
+  }'
+```
+
+## Development
+
+### Running Tests
+
+```bash
+pytest
+```
+
+### Code Linting
+
+```bash
+ruff check .
+```
+
+### Code Formatting
+
+```bash
+ruff format .
+```

alembic.ini

@@ -0,0 +1,85 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = migrations
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# timezone to use when rendering the date
+# within the migration file as well as the filename.
+# string value is passed to dateutil.tz.gettz()
+# leave blank for localtime
+# timezone =
+
+# max length of characters to apply to the
+# "slug" field
+# truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; this defaults
+# to migrations/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path
+# version_locations = %(here)s/bar %(here)s/bat migrations/versions
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+# SQLite URL using absolute path
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+[post_write_hooks]
+# post_write_hooks defines scripts or Python functions that are run
+# on newly generated revision scripts.  See the documentation for further
+# detail and examples
+
+# format using "black" - use the console_scripts runner, against the "black" entrypoint
+# hooks=black
+# black.type=console_scripts
+# black.entrypoint=black
+# black.options=-l 79
+
+# Logging configuration
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

app/api/deps.py

@@ -0,0 +1,46 @@
+
+from fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer
+from jose import jwt, JWTError
+from pydantic import ValidationError
+from sqlalchemy.orm import Session
+
+from app import models, schemas
+from app.core.config import settings
+from app.db.session import get_db
+from app.crud.user import get_user_by_id
+
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/v1/login/access-token")
+
+
+def get_current_user(
+    db: Session = Depends(get_db), token: str = Depends(oauth2_scheme)
+) -> models.User:
+    """
+    Get the current user from the token
+    """
+    try:
+        payload = jwt.decode(
+            token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM]
+        )
+        token_data = schemas.TokenPayload(**payload)
+    except (JWTError, ValidationError):
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Could not validate credentials",
+        )
+    user = get_user_by_id(db, id=token_data.sub)
+    if not user:
+        raise HTTPException(status_code=404, detail="User not found")
+    return user
+
+
+def get_current_active_user(
+    current_user: models.User = Depends(get_current_user),
+) -> models.User:
+    """
+    Get the current active user
+    """
+    if not current_user.is_active:
+        raise HTTPException(status_code=400, detail="Inactive user")
+    return current_user

app/api/v1/__init__.py

@@ -0,0 +1,11 @@
+from fastapi import APIRouter
+
+from app.api.v1 import health, users, login, accounts, transactions
+
+api_router = APIRouter()
+
+api_router.include_router(health.router, prefix="/health", tags=["health"])
+api_router.include_router(login.router, prefix="/login", tags=["login"])
+api_router.include_router(users.router, prefix="/users", tags=["users"])
+api_router.include_router(accounts.router, prefix="/accounts", tags=["accounts"])
+api_router.include_router(transactions.router, prefix="/transactions", tags=["transactions"])

app/api/v1/accounts.py

@@ -0,0 +1,92 @@
+from typing import Any, List
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app import crud, models, schemas
+from app.api import deps
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[schemas.Account])
+def read_accounts(
+    skip: int = 0,
+    limit: int = 100,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Retrieve accounts for the current user.
+    """
+    accounts = crud.get_user_accounts(db, owner_id=current_user.id, skip=skip, limit=limit)
+    return accounts
+
+
+@router.post("/", response_model=schemas.Account)
+def create_account(
+    account_in: schemas.AccountCreate,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Create new account for the current user.
+    """
+    account = crud.create_account(db, account_in=account_in, owner_id=current_user.id)
+    return account
+
+
+@router.get("/{account_id}", response_model=schemas.Account)
+def read_account(
+    account_id: int,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Get account by ID.
+    """
+    account = crud.get_account_by_id(db, id=account_id)
+    if not account:
+        raise HTTPException(status_code=404, detail="Account not found")
+    if account.owner_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not enough permissions")
+    return account
+
+
+@router.put("/{account_id}", response_model=schemas.Account)
+def update_account(
+    account_id: int,
+    account_in: schemas.AccountUpdate,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Update an account.
+    """
+    account = crud.get_account_by_id(db, id=account_id)
+    if not account:
+        raise HTTPException(status_code=404, detail="Account not found")
+    if account.owner_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not enough permissions")
+    account = crud.update_account(db, account=account, account_in=account_in)
+    return account
+
+
+@router.delete("/{account_id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
+def delete_account(
+    account_id: int,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> None:
+    """
+    Delete an account.
+    """
+    account = crud.get_account_by_id(db, id=account_id)
+    if not account:
+        raise HTTPException(status_code=404, detail="Account not found")
+    if account.owner_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not enough permissions")
+    if account.balance > 0:
+        raise HTTPException(status_code=400, detail="Cannot delete account with positive balance")
+    crud.delete_account(db, account=account)
+    return None

app/api/v1/health.py

@@ -0,0 +1,22 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+
+from app.db.session import get_db
+
+router = APIRouter()
+
+
+@router.get("")
+def health_check(db: Session = Depends(get_db)):
+    """
+    Check the health of the application.
+    
+    This endpoint can be used to verify that the application is running
+    and able to connect to the database.
+    """
+    try:
+        # Try to execute a simple query
+        db.execute("SELECT 1")
+        return {"status": "healthy", "database": "connected"}
+    except Exception as e:
+        return {"status": "unhealthy", "database": str(e)}

app/api/v1/login.py

@@ -0,0 +1,40 @@
+from datetime import timedelta
+from typing import Any
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordRequestForm
+from sqlalchemy.orm import Session
+
+from app import crud, schemas
+from app.api import deps
+from app.core import security
+from app.core.config import settings
+
+router = APIRouter()
+
+
+@router.post("/access-token", response_model=schemas.Token)
+def login_access_token(
+    db: Session = Depends(deps.get_db),
+    form_data: OAuth2PasswordRequestForm = Depends(),
+) -> Any:
+    """
+    OAuth2 compatible token login, get an access token for future requests.
+    """
+    user = crud.authenticate(
+        db, email=form_data.username, password=form_data.password
+    )
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Incorrect email or password",
+        )
+    if not user.is_active:
+        raise HTTPException(status_code=400, detail="Inactive user")
+    access_token_expires = timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
+    return {
+        "access_token": security.create_access_token(
+            user.id, expires_delta=access_token_expires
+        ),
+        "token_type": "bearer",
+    }

app/api/v1/transactions.py

@@ -0,0 +1,196 @@
+from typing import Any, List
+
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.orm import Session
+
+from app import crud, models, schemas
+from app.api import deps
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[schemas.Transaction])
+def read_transactions(
+    skip: int = 0,
+    limit: int = 100,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Retrieve transactions for the current user.
+    """
+    transactions = crud.get_user_transactions(db, user_id=current_user.id, skip=skip, limit=limit)
+    return transactions
+
+
+@router.get("/account/{account_id}", response_model=List[schemas.Transaction])
+def read_account_transactions(
+    account_id: int,
+    skip: int = 0,
+    limit: int = 100,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Retrieve transactions for a specific account.
+    """
+    account = crud.get_account_by_id(db, id=account_id)
+    if not account:
+        raise HTTPException(status_code=404, detail="Account not found")
+    if account.owner_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not enough permissions")
+    
+    transactions = crud.get_account_transactions(db, account_id=account_id, skip=skip, limit=limit)
+    return transactions
+
+
+@router.post("/deposit", response_model=schemas.Transaction)
+def create_deposit(
+    deposit_in: schemas.DepositCreate,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Create a deposit transaction.
+    """
+    # Verify account ownership
+    account = crud.get_account_by_id(db, id=deposit_in.account_id)
+    if not account:
+        raise HTTPException(status_code=404, detail="Account not found")
+    if account.owner_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not enough permissions")
+    
+    # Create and process transaction
+    transaction = crud.create_deposit(db, deposit_in=deposit_in, user_id=current_user.id)
+    transaction = crud.process_transaction(db, transaction=transaction)
+    
+    return transaction
+
+
+@router.post("/withdrawal", response_model=schemas.Transaction)
+def create_withdrawal(
+    withdrawal_in: schemas.WithdrawalCreate,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Create a withdrawal transaction.
+    """
+    # Verify account ownership
+    account = crud.get_account_by_id(db, id=withdrawal_in.account_id)
+    if not account:
+        raise HTTPException(status_code=404, detail="Account not found")
+    if account.owner_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not enough permissions")
+    
+    # Check sufficient balance
+    if account.balance < withdrawal_in.amount:
+        raise HTTPException(status_code=400, detail="Insufficient funds")
+    
+    # Create and process transaction
+    transaction = crud.create_withdrawal(db, withdrawal_in=withdrawal_in, user_id=current_user.id)
+    transaction = crud.process_transaction(db, transaction=transaction)
+    
+    return transaction
+
+
+@router.post("/transfer", response_model=schemas.Transaction)
+def create_transfer(
+    transfer_in: schemas.TransferCreate,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Create a transfer transaction between accounts.
+    """
+    # Verify sender account ownership
+    sender_account = crud.get_account_by_id(db, id=transfer_in.sender_account_id)
+    if not sender_account:
+        raise HTTPException(status_code=404, detail="Sender account not found")
+    if sender_account.owner_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not enough permissions")
+    
+    # Verify receiver account exists
+    receiver_account = crud.get_account_by_id(db, id=transfer_in.receiver_account_id)
+    if not receiver_account:
+        raise HTTPException(status_code=404, detail="Receiver account not found")
+    
+    # Check sufficient balance
+    if sender_account.balance < transfer_in.amount:
+        raise HTTPException(status_code=400, detail="Insufficient funds")
+    
+    # Create and process transaction
+    transaction = crud.create_transfer(db, transfer_in=transfer_in, user_id=current_user.id)
+    transaction = crud.process_transaction(db, transaction=transaction)
+    
+    return transaction
+
+
+@router.post("/receive", response_model=schemas.Transaction)
+def receive_money(
+    receive_in: schemas.ReceiveMoneyCreate,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Receive money from an external source.
+    """
+    # Verify account ownership
+    account = crud.get_account_by_id(db, id=receive_in.receiver_account_id)
+    if not account:
+        raise HTTPException(status_code=404, detail="Account not found")
+    if account.owner_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not enough permissions")
+    
+    # Create and process transaction
+    transaction = crud.create_receive_money(db, receive_in=receive_in, user_id=current_user.id)
+    transaction = crud.process_transaction(db, transaction=transaction)
+    
+    return transaction
+
+
+@router.post("/send", response_model=schemas.Transaction)
+def send_money(
+    send_in: schemas.SendMoneyCreate,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Send money to an external destination.
+    """
+    # Verify account ownership
+    account = crud.get_account_by_id(db, id=send_in.sender_account_id)
+    if not account:
+        raise HTTPException(status_code=404, detail="Account not found")
+    if account.owner_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not enough permissions")
+    
+    # Check sufficient balance
+    if account.balance < send_in.amount:
+        raise HTTPException(status_code=400, detail="Insufficient funds")
+    
+    # Create and process transaction
+    transaction = crud.create_send_money(db, send_in=send_in, user_id=current_user.id)
+    transaction = crud.process_transaction(db, transaction=transaction)
+    
+    return transaction
+
+
+@router.get("/{transaction_id}", response_model=schemas.Transaction)
+def read_transaction(
+    transaction_id: int,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Get transaction by ID.
+    """
+    transaction = crud.get_transaction_by_id(db, id=transaction_id)
+    if not transaction:
+        raise HTTPException(status_code=404, detail="Transaction not found")
+    
+    # Verify user is involved in the transaction
+    if transaction.sender_id != current_user.id and transaction.receiver_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not enough permissions")
+    
+    return transaction

app/api/v1/users.py

@@ -0,0 +1,70 @@
+from typing import Any
+
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.orm import Session
+
+from app import crud, models, schemas
+from app.api import deps
+
+router = APIRouter()
+
+
+@router.post("/", response_model=schemas.User)
+def create_user(
+    user_in: schemas.UserCreate,
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Create a new user.
+    """
+    user = crud.get_user_by_email(db, email=user_in.email)
+    if user:
+        raise HTTPException(
+            status_code=400,
+            detail="A user with this email already exists",
+        )
+    user = crud.create_user(db, user_in=user_in)
+    return user
+
+
+@router.get("/me", response_model=schemas.User)
+def read_user_me(
+    current_user: models.User = Depends(deps.get_current_active_user),
+) -> Any:
+    """
+    Get current user.
+    """
+    return current_user
+
+
+@router.put("/me", response_model=schemas.User)
+def update_user_me(
+    user_in: schemas.UserUpdate,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Update current user.
+    """
+    user = crud.update_user(db, user=current_user, user_in=user_in)
+    return user
+
+
+@router.get("/{user_id}", response_model=schemas.User)
+def read_user_by_id(
+    user_id: int,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Get a specific user by id.
+    """
+    user = crud.get_user_by_id(db, id=user_id)
+    if user == current_user:
+        return user
+    if not user:
+        raise HTTPException(
+            status_code=404,
+            detail="User not found",
+        )
+    return user

app/core/config.py

@@ -0,0 +1,26 @@
+from pydantic_settings import BaseSettings
+from pathlib import Path
+
+
+class Settings(BaseSettings):
+    PROJECT_NAME: str = "Fintech Payment Service"
+    PROJECT_DESCRIPTION: str = "A FastAPI backend for fintech payment services"
+    VERSION: str = "0.1.0"
+
+    # Security settings
+    SECRET_KEY: str = "supersecretkey"  # Change in production
+    ALGORITHM: str = "HS256"
+    ACCESS_TOKEN_EXPIRE_MINUTES: int = 30
+    
+    # Database settings
+    DB_DIR = Path("/app") / "storage" / "db"
+    DB_DIR.mkdir(parents=True, exist_ok=True)
+    SQLALCHEMY_DATABASE_URL: str = f"sqlite:///{DB_DIR}/db.sqlite"
+
+    class Config:
+        env_file = ".env"
+        env_file_encoding = "utf-8"
+        case_sensitive = True
+
+
+settings = Settings()

app/core/security.py

@@ -0,0 +1,42 @@
+from datetime import datetime, timedelta
+from typing import Any, Union
+
+from jose import jwt
+from passlib.context import CryptContext
+
+from app.core.config import settings
+
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+
+def create_access_token(
+    subject: Union[str, Any], expires_delta: timedelta = None
+) -> str:
+    """
+    Create a JWT access token
+    """
+    if expires_delta:
+        expire = datetime.utcnow() + expires_delta
+    else:
+        expire = datetime.utcnow() + timedelta(
+            minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES
+        )
+    to_encode = {"exp": expire, "sub": str(subject)}
+    encoded_jwt = jwt.encode(
+        to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM
+    )
+    return encoded_jwt
+
+
+def verify_password(plain_password: str, hashed_password: str) -> bool:
+    """
+    Verify a password against a hash
+    """
+    return pwd_context.verify(plain_password, hashed_password)
+
+
+def get_password_hash(password: str) -> str:
+    """
+    Hash a password
+    """
+    return pwd_context.hash(password)

app/crud/__init__.py

@@ -0,0 +1,37 @@
+from app.crud.user import get_user_by_id, get_user_by_email, get_users, create_user, update_user, delete_user, authenticate
+from app.crud.account import get_account_by_id, get_account_by_number, get_user_accounts, create_account, update_account, delete_account, update_account_balance
+from app.crud.transaction import get_transaction_by_id, get_transaction_by_reference, get_user_transactions, get_account_transactions, create_deposit, create_withdrawal, create_transfer, create_receive_money, create_send_money, update_transaction, process_transaction
+
+# Define __all__ to make explicit what's exported from this module
+__all__ = [
+    # User CRUD
+    "get_user_by_id",
+    "get_user_by_email",
+    "get_users",
+    "create_user",
+    "update_user",
+    "delete_user",
+    "authenticate",
+    
+    # Account CRUD
+    "get_account_by_id",
+    "get_account_by_number",
+    "get_user_accounts",
+    "create_account",
+    "update_account",
+    "delete_account",
+    "update_account_balance",
+    
+    # Transaction CRUD
+    "get_transaction_by_id",
+    "get_transaction_by_reference",
+    "get_user_transactions",
+    "get_account_transactions",
+    "create_deposit",
+    "create_withdrawal",
+    "create_transfer",
+    "create_receive_money",
+    "create_send_money",
+    "update_transaction",
+    "process_transaction",
+]

app/crud/account.py

@@ -0,0 +1,94 @@
+from typing import Optional, List
+import random
+import string
+
+from sqlalchemy.orm import Session
+
+from app.models.account import Account
+from app.schemas.account import AccountCreate, AccountUpdate
+
+
+def generate_account_number() -> str:
+    """
+    Generate a random account number
+    """
+    # Generate a 10-digit account number
+    return ''.join(random.choices(string.digits, k=10))
+
+
+def get_account_by_id(db: Session, id: int) -> Optional[Account]:
+    """
+    Get an account by ID
+    """
+    return db.query(Account).filter(Account.id == id).first()
+
+
+def get_account_by_number(db: Session, account_number: str) -> Optional[Account]:
+    """
+    Get an account by account number
+    """
+    return db.query(Account).filter(Account.account_number == account_number).first()
+
+
+def get_user_accounts(db: Session, owner_id: int, skip: int = 0, limit: int = 100) -> List[Account]:
+    """
+    Get all accounts owned by a user
+    """
+    return db.query(Account).filter(Account.owner_id == owner_id).offset(skip).limit(limit).all()
+
+
+def create_account(db: Session, account_in: AccountCreate, owner_id: int) -> Account:
+    """
+    Create a new account for a user
+    """
+    # Generate a unique account number
+    account_number = generate_account_number()
+    while get_account_by_number(db, account_number):
+        account_number = generate_account_number()
+    
+    db_account = Account(
+        account_number=account_number,
+        owner_id=owner_id,
+        account_type=account_in.account_type,
+        balance=0.0,
+        currency=account_in.currency,
+    )
+    db.add(db_account)
+    db.commit()
+    db.refresh(db_account)
+    return db_account
+
+
+def update_account(db: Session, account: Account, account_in: AccountUpdate) -> Account:
+    """
+    Update an account
+    """
+    update_data = account_in.dict(exclude_unset=True)
+    
+    for field, value in update_data.items():
+        setattr(account, field, value)
+    
+    db.add(account)
+    db.commit()
+    db.refresh(account)
+    return account
+
+
+def delete_account(db: Session, account: Account) -> Account:
+    """
+    Delete an account
+    """
+    db.delete(account)
+    db.commit()
+    return account
+
+
+def update_account_balance(db: Session, account: Account, amount: float) -> Account:
+    """
+    Update an account balance
+    """
+    account.balance += amount
+    db.add(account)
+    db.commit()
+    db.refresh(account)
+    return account

app/crud/transaction.py

@@ -0,0 +1,292 @@
+from typing import Optional, List
+import random
+import string
+from datetime import datetime
+
+from sqlalchemy.orm import Session
+from sqlalchemy import or_
+
+from app.models.transaction import Transaction, TransactionType, TransactionStatus
+from app.models.account import Account
+from app.crud.account import update_account_balance
+from app.schemas.transaction import (
+    TransferCreate, 
+    DepositCreate, 
+    WithdrawalCreate,
+    ReceiveMoneyCreate,
+    SendMoneyCreate,
+    TransactionUpdate
+)
+
+
+def generate_transaction_reference() -> str:
+    """
+    Generate a random transaction reference
+    """
+    # Generate a 12-character transaction reference
+    chars = string.ascii_uppercase + string.digits
+    return 'TX-' + ''.join(random.choices(chars, k=12))
+
+
+def get_transaction_by_id(db: Session, id: int) -> Optional[Transaction]:
+    """
+    Get a transaction by ID
+    """
+    return db.query(Transaction).filter(Transaction.id == id).first()
+
+
+def get_transaction_by_reference(db: Session, reference: str) -> Optional[Transaction]:
+    """
+    Get a transaction by reference
+    """
+    return db.query(Transaction).filter(Transaction.transaction_reference == reference).first()
+
+
+def get_user_transactions(db: Session, user_id: int, skip: int = 0, limit: int = 100) -> List[Transaction]:
+    """
+    Get all transactions for a user (sent or received)
+    """
+    return db.query(Transaction).filter(
+        or_(
+            Transaction.sender_id == user_id,
+            Transaction.receiver_id == user_id
+        )
+    ).offset(skip).limit(limit).all()
+
+
+def get_account_transactions(db: Session, account_id: int, skip: int = 0, limit: int = 100) -> List[Transaction]:
+    """
+    Get all transactions for an account (sent or received)
+    """
+    return db.query(Transaction).filter(
+        or_(
+            Transaction.sender_account_id == account_id,
+            Transaction.receiver_account_id == account_id
+        )
+    ).offset(skip).limit(limit).all()
+
+
+def create_deposit(db: Session, deposit_in: DepositCreate, user_id: int) -> Transaction:
+    """
+    Create a deposit transaction
+    """
+    # Generate a unique transaction reference
+    transaction_reference = generate_transaction_reference()
+    while get_transaction_by_reference(db, transaction_reference):
+        transaction_reference = generate_transaction_reference()
+    
+    # Create the transaction
+    db_transaction = Transaction(
+        transaction_reference=transaction_reference,
+        receiver_id=user_id,
+        receiver_account_id=deposit_in.account_id,
+        amount=deposit_in.amount,
+        currency=deposit_in.currency,
+        transaction_type=TransactionType.DEPOSIT,
+        status=TransactionStatus.PENDING,
+        description=deposit_in.description,
+    )
+    db.add(db_transaction)
+    db.commit()
+    db.refresh(db_transaction)
+    
+    return db_transaction
+
+
+def create_withdrawal(db: Session, withdrawal_in: WithdrawalCreate, user_id: int) -> Transaction:
+    """
+    Create a withdrawal transaction
+    """
+    # Generate a unique transaction reference
+    transaction_reference = generate_transaction_reference()
+    while get_transaction_by_reference(db, transaction_reference):
+        transaction_reference = generate_transaction_reference()
+    
+    # Create the transaction
+    db_transaction = Transaction(
+        transaction_reference=transaction_reference,
+        sender_id=user_id,
+        sender_account_id=withdrawal_in.account_id,
+        amount=withdrawal_in.amount,
+        currency=withdrawal_in.currency,
+        transaction_type=TransactionType.WITHDRAWAL,
+        status=TransactionStatus.PENDING,
+        description=withdrawal_in.description,
+    )
+    db.add(db_transaction)
+    db.commit()
+    db.refresh(db_transaction)
+    
+    return db_transaction
+
+
+def create_transfer(db: Session, transfer_in: TransferCreate, user_id: int) -> Transaction:
+    """
+    Create a transfer transaction
+    """
+    # Generate a unique transaction reference
+    transaction_reference = generate_transaction_reference()
+    while get_transaction_by_reference(db, transaction_reference):
+        transaction_reference = generate_transaction_reference()
+    
+    # Create the transaction
+    db_transaction = Transaction(
+        transaction_reference=transaction_reference,
+        sender_id=user_id,
+        sender_account_id=transfer_in.sender_account_id,
+        receiver_account_id=transfer_in.receiver_account_id,
+        amount=transfer_in.amount,
+        currency=transfer_in.currency,
+        transaction_type=TransactionType.TRANSFER,
+        status=TransactionStatus.PENDING,
+        description=transfer_in.description,
+    )
+    
+    # Get the receiver account to set the receiver_id
+    receiver_account = db.query(Account).filter(Account.id == transfer_in.receiver_account_id).first()
+    if receiver_account:
+        db_transaction.receiver_id = receiver_account.owner_id
+    
+    db.add(db_transaction)
+    db.commit()
+    db.refresh(db_transaction)
+    
+    return db_transaction
+
+
+def create_receive_money(db: Session, receive_in: ReceiveMoneyCreate, user_id: int) -> Transaction:
+    """
+    Create a transaction for receiving money from an external source
+    """
+    # Generate a unique transaction reference
+    transaction_reference = generate_transaction_reference()
+    while get_transaction_by_reference(db, transaction_reference):
+        transaction_reference = generate_transaction_reference()
+    
+    # Create the transaction
+    db_transaction = Transaction(
+        transaction_reference=transaction_reference,
+        receiver_id=user_id,
+        receiver_account_id=receive_in.receiver_account_id,
+        amount=receive_in.amount,
+        currency=receive_in.currency,
+        transaction_type=TransactionType.DEPOSIT,
+        status=TransactionStatus.PENDING,
+        description=f"External deposit from: {receive_in.external_sender_info}. {receive_in.description or ''}",
+    )
+    db.add(db_transaction)
+    db.commit()
+    db.refresh(db_transaction)
+    
+    return db_transaction
+
+
+def create_send_money(db: Session, send_in: SendMoneyCreate, user_id: int) -> Transaction:
+    """
+    Create a transaction for sending money to an external destination
+    """
+    # Generate a unique transaction reference
+    transaction_reference = generate_transaction_reference()
+    while get_transaction_by_reference(db, transaction_reference):
+        transaction_reference = generate_transaction_reference()
+    
+    # Create the transaction
+    db_transaction = Transaction(
+        transaction_reference=transaction_reference,
+        sender_id=user_id,
+        sender_account_id=send_in.sender_account_id,
+        amount=send_in.amount,
+        currency=send_in.currency,
+        transaction_type=TransactionType.WITHDRAWAL,
+        status=TransactionStatus.PENDING,
+        description=f"External withdrawal to: {send_in.external_receiver_info}. {send_in.description or ''}",
+    )
+    db.add(db_transaction)
+    db.commit()
+    db.refresh(db_transaction)
+    
+    return db_transaction
+
+
+def update_transaction(db: Session, transaction: Transaction, transaction_in: TransactionUpdate) -> Transaction:
+    """
+    Update a transaction
+    """
+    update_data = transaction_in.dict(exclude_unset=True)
+    
+    # If status is changing to completed, set the completed_at timestamp
+    if "status" in update_data and update_data["status"] == TransactionStatus.COMPLETED and transaction.status != TransactionStatus.COMPLETED:
+        update_data["completed_at"] = datetime.utcnow()
+    
+    for field, value in update_data.items():
+        setattr(transaction, field, value)
+    
+    db.add(transaction)
+    db.commit()
+    db.refresh(transaction)
+    return transaction
+
+
+def process_transaction(db: Session, transaction: Transaction) -> Transaction:
+    """
+    Process a pending transaction
+    """
+    # Only process pending transactions
+    if transaction.status != TransactionStatus.PENDING:
+        return transaction
+    
+    try:
+        # Process based on transaction type
+        if transaction.transaction_type == TransactionType.DEPOSIT:
+            # Handle deposit
+            if transaction.receiver_account_id:
+                receiver_account = db.query(Account).filter(Account.id == transaction.receiver_account_id).first()
+                if receiver_account:
+                    update_account_balance(db, receiver_account, transaction.amount)
+                    transaction.status = TransactionStatus.COMPLETED
+                    transaction.completed_at = datetime.utcnow()
+        
+        elif transaction.transaction_type == TransactionType.WITHDRAWAL:
+            # Handle withdrawal
+            if transaction.sender_account_id:
+                sender_account = db.query(Account).filter(Account.id == transaction.sender_account_id).first()
+                if sender_account:
+                    # Check if there's enough balance
+                    if sender_account.balance >= transaction.amount:
+                        update_account_balance(db, sender_account, -transaction.amount)
+                        transaction.status = TransactionStatus.COMPLETED
+                        transaction.completed_at = datetime.utcnow()
+                    else:
+                        transaction.status = TransactionStatus.FAILED
+                        transaction.description = transaction.description + " (Insufficient funds)"
+        
+        elif transaction.transaction_type == TransactionType.TRANSFER:
+            # Handle transfer between accounts
+            if transaction.sender_account_id and transaction.receiver_account_id:
+                sender_account = db.query(Account).filter(Account.id == transaction.sender_account_id).first()
+                receiver_account = db.query(Account).filter(Account.id == transaction.receiver_account_id).first()
+                
+                if sender_account and receiver_account:
+                    # Check if there's enough balance
+                    if sender_account.balance >= transaction.amount:
+                        update_account_balance(db, sender_account, -transaction.amount)
+                        update_account_balance(db, receiver_account, transaction.amount)
+                        transaction.status = TransactionStatus.COMPLETED
+                        transaction.completed_at = datetime.utcnow()
+                    else:
+                        transaction.status = TransactionStatus.FAILED
+                        transaction.description = transaction.description + " (Insufficient funds)"
+        
+        db.add(transaction)
+        db.commit()
+        db.refresh(transaction)
+        return transaction
+    
+    except Exception as e:
+        # If there's an error, mark the transaction as failed
+        transaction.status = TransactionStatus.FAILED
+        transaction.description = transaction.description + f" (Error: {str(e)})"
+        db.add(transaction)
+        db.commit()
+        db.refresh(transaction)
+        return transaction

app/crud/user.py

@@ -0,0 +1,85 @@
+from typing import Optional, List
+
+from sqlalchemy.orm import Session
+
+from app.core.security import get_password_hash, verify_password
+from app.models.user import User
+from app.schemas.user import UserCreate, UserUpdate
+
+
+def get_user_by_id(db: Session, id: int) -> Optional[User]:
+    """
+    Get a user by ID
+    """
+    return db.query(User).filter(User.id == id).first()
+
+
+def get_user_by_email(db: Session, email: str) -> Optional[User]:
+    """
+    Get a user by email
+    """
+    return db.query(User).filter(User.email == email).first()
+
+
+def get_users(db: Session, skip: int = 0, limit: int = 100) -> List[User]:
+    """
+    Get a list of users
+    """
+    return db.query(User).offset(skip).limit(limit).all()
+
+
+def create_user(db: Session, user_in: UserCreate) -> User:
+    """
+    Create a new user
+    """
+    db_user = User(
+        email=user_in.email,
+        first_name=user_in.first_name,
+        last_name=user_in.last_name,
+        hashed_password=get_password_hash(user_in.password),
+        is_active=user_in.is_active,
+    )
+    db.add(db_user)
+    db.commit()
+    db.refresh(db_user)
+    return db_user
+
+
+def update_user(db: Session, user: User, user_in: UserUpdate) -> User:
+    """
+    Update a user
+    """
+    update_data = user_in.dict(exclude_unset=True)
+    if update_data.get("password"):
+        hashed_password = get_password_hash(update_data["password"])
+        del update_data["password"]
+        update_data["hashed_password"] = hashed_password
+    
+    for field, value in update_data.items():
+        setattr(user, field, value)
+    
+    db.add(user)
+    db.commit()
+    db.refresh(user)
+    return user
+
+
+def delete_user(db: Session, user: User) -> User:
+    """
+    Delete a user
+    """
+    db.delete(user)
+    db.commit()
+    return user
+
+
+def authenticate(db: Session, email: str, password: str) -> Optional[User]:
+    """
+    Authenticate a user
+    """
+    user = get_user_by_email(db, email=email)
+    if not user:
+        return None
+    if not verify_password(password, user.hashed_password):
+        return None
+    return user

app/db/base.py

@@ -0,0 +1,3 @@
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()

app/db/session.py

@@ -0,0 +1,18 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+
+from app.core.config import settings
+
+engine = create_engine(
+    settings.SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False},
+)
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+# Dependency to get DB session
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/__init__.py

@@ -0,0 +1,13 @@
+from app.models.user import User
+from app.models.account import Account, AccountType
+from app.models.transaction import Transaction, TransactionType, TransactionStatus
+
+# Define __all__ to make explicit what's exported from this module
+__all__ = [
+    "User",
+    "Account",
+    "AccountType",
+    "Transaction",
+    "TransactionType",
+    "TransactionStatus",
+]

app/models/account.py

@@ -0,0 +1,38 @@
+from sqlalchemy import Column, Integer, String, Float, ForeignKey, DateTime, Enum
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+import enum
+
+from app.db.base import Base
+
+
+class AccountType(str, enum.Enum):
+    SAVINGS = "savings"
+    CHECKING = "checking"
+    INVESTMENT = "investment"
+
+
+class Account(Base):
+    __tablename__ = "accounts"
+
+    id = Column(Integer, primary_key=True, index=True)
+    account_number = Column(String, unique=True, index=True, nullable=False)
+    owner_id = Column(Integer, ForeignKey("users.id"), nullable=False)
+    account_type = Column(Enum(AccountType), nullable=False)
+    balance = Column(Float, default=0.0, nullable=False)
+    currency = Column(String, default="USD", nullable=False)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+    
+    # Relationships
+    owner = relationship("User", back_populates="accounts")
+    sent_transactions = relationship(
+        "Transaction", 
+        foreign_keys="[Transaction.sender_account_id]", 
+        back_populates="sender_account"
+    )
+    received_transactions = relationship(
+        "Transaction", 
+        foreign_keys="[Transaction.receiver_account_id]", 
+        back_populates="receiver_account"
+    )

app/models/transaction.py

@@ -0,0 +1,50 @@
+from sqlalchemy import Column, Integer, String, Float, ForeignKey, DateTime, Enum
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+import enum
+
+from app.db.base import Base
+
+
+class TransactionType(str, enum.Enum):
+    DEPOSIT = "deposit"
+    WITHDRAWAL = "withdrawal"
+    TRANSFER = "transfer"
+
+
+class TransactionStatus(str, enum.Enum):
+    PENDING = "pending"
+    COMPLETED = "completed"
+    FAILED = "failed"
+    CANCELLED = "cancelled"
+
+
+class Transaction(Base):
+    __tablename__ = "transactions"
+
+    id = Column(Integer, primary_key=True, index=True)
+    transaction_reference = Column(String, unique=True, index=True, nullable=False)
+    
+    sender_id = Column(Integer, ForeignKey("users.id"), nullable=True)
+    sender_account_id = Column(Integer, ForeignKey("accounts.id"), nullable=True)
+    
+    receiver_id = Column(Integer, ForeignKey("users.id"), nullable=True)
+    receiver_account_id = Column(Integer, ForeignKey("accounts.id"), nullable=True)
+    
+    amount = Column(Float, nullable=False)
+    currency = Column(String, default="USD", nullable=False)
+    
+    transaction_type = Column(Enum(TransactionType), nullable=False)
+    status = Column(Enum(TransactionStatus), default=TransactionStatus.PENDING, nullable=False)
+    
+    description = Column(String, nullable=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+    completed_at = Column(DateTime(timezone=True), nullable=True)
+    
+    # Relationships
+    sender = relationship("User", foreign_keys=[sender_id], back_populates="sent_transactions")
+    receiver = relationship("User", foreign_keys=[receiver_id], back_populates="received_transactions")
+    
+    sender_account = relationship("Account", foreign_keys=[sender_account_id], back_populates="sent_transactions")
+    receiver_account = relationship("Account", foreign_keys=[receiver_account_id], back_populates="received_transactions")

app/models/user.py

@@ -0,0 +1,31 @@
+from sqlalchemy import Column, Integer, String, Boolean, DateTime
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from app.db.base import Base
+
+
+class User(Base):
+    __tablename__ = "users"
+
+    id = Column(Integer, primary_key=True, index=True)
+    email = Column(String, unique=True, index=True, nullable=False)
+    first_name = Column(String, nullable=False)
+    last_name = Column(String, nullable=False)
+    hashed_password = Column(String, nullable=False)
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+    
+    # Relationships
+    accounts = relationship("Account", back_populates="owner", cascade="all, delete-orphan")
+    sent_transactions = relationship(
+        "Transaction", 
+        foreign_keys="[Transaction.sender_id]", 
+        back_populates="sender"
+    )
+    received_transactions = relationship(
+        "Transaction", 
+        foreign_keys="[Transaction.receiver_id]", 
+        back_populates="receiver"
+    )

app/schemas/__init__.py

@@ -0,0 +1,44 @@
+from app.schemas.user import User, UserCreate, UserUpdate, UserInDB
+from app.schemas.account import Account, AccountCreate, AccountUpdate, AccountType
+from app.schemas.transaction import (
+    Transaction, 
+    TransactionType, 
+    TransactionStatus,
+    DepositCreate, 
+    WithdrawalCreate, 
+    TransferCreate,
+    ReceiveMoneyCreate,
+    SendMoneyCreate,
+    TransactionUpdate
+)
+from app.schemas.token import Token, TokenPayload
+
+# Define __all__ to make explicit what's exported from this module
+__all__ = [
+    # User schemas
+    "User",
+    "UserCreate",
+    "UserUpdate",
+    "UserInDB",
+    
+    # Account schemas
+    "Account",
+    "AccountCreate",
+    "AccountUpdate",
+    "AccountType",
+    
+    # Transaction schemas
+    "Transaction",
+    "TransactionType",
+    "TransactionStatus",
+    "DepositCreate",
+    "WithdrawalCreate",
+    "TransferCreate",
+    "ReceiveMoneyCreate",
+    "SendMoneyCreate",
+    "TransactionUpdate",
+    
+    # Token schemas
+    "Token",
+    "TokenPayload",
+]

app/schemas/account.py

@@ -0,0 +1,43 @@
+from pydantic import BaseModel
+from typing import Optional
+from datetime import datetime
+from enum import Enum
+
+
+class AccountType(str, Enum):
+    SAVINGS = "savings"
+    CHECKING = "checking"
+    INVESTMENT = "investment"
+
+
+class AccountBase(BaseModel):
+    account_type: AccountType
+    currency: str = "USD"
+
+
+class AccountCreate(AccountBase):
+    """Request model for creating a new account"""
+    pass
+
+
+class AccountUpdate(BaseModel):
+    """Request model for updating an existing account"""
+    account_type: Optional[AccountType] = None
+    currency: Optional[str] = None
+
+
+class AccountInDBBase(AccountBase):
+    id: int
+    account_number: str
+    owner_id: int
+    balance: float
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True
+
+
+class Account(AccountInDBBase):
+    """Response model for account data"""
+    pass

app/schemas/token.py

@@ -0,0 +1,11 @@
+from pydantic import BaseModel
+from typing import Optional
+
+
+class Token(BaseModel):
+    access_token: str
+    token_type: str
+
+
+class TokenPayload(BaseModel):
+    sub: Optional[int] = None

app/schemas/transaction.py

@@ -0,0 +1,79 @@
+from pydantic import BaseModel, Field
+from typing import Optional
+from datetime import datetime
+from enum import Enum
+
+
+class TransactionType(str, Enum):
+    DEPOSIT = "deposit"
+    WITHDRAWAL = "withdrawal"
+    TRANSFER = "transfer"
+
+
+class TransactionStatus(str, Enum):
+    PENDING = "pending"
+    COMPLETED = "completed"
+    FAILED = "failed"
+    CANCELLED = "cancelled"
+
+
+class TransactionBase(BaseModel):
+    amount: float = Field(..., gt=0)
+    currency: str = "USD"
+    description: Optional[str] = None
+
+
+class DepositCreate(TransactionBase):
+    """Request model for creating a deposit"""
+    account_id: int
+
+
+class WithdrawalCreate(TransactionBase):
+    """Request model for creating a withdrawal"""
+    account_id: int
+
+
+class TransferCreate(TransactionBase):
+    """Request model for creating a transfer between accounts"""
+    sender_account_id: int
+    receiver_account_id: int
+
+
+class ReceiveMoneyCreate(TransactionBase):
+    """Request model for receiving money from external source"""
+    receiver_account_id: int
+    external_sender_info: str
+
+
+class SendMoneyCreate(TransactionBase):
+    """Request model for sending money to external destination"""
+    sender_account_id: int
+    external_receiver_info: str
+
+
+class TransactionUpdate(BaseModel):
+    """Request model for updating a transaction"""
+    status: Optional[TransactionStatus] = None
+    description: Optional[str] = None
+
+
+class TransactionInDBBase(TransactionBase):
+    id: int
+    transaction_reference: str
+    sender_id: Optional[int] = None
+    sender_account_id: Optional[int] = None
+    receiver_id: Optional[int] = None
+    receiver_account_id: Optional[int] = None
+    transaction_type: TransactionType
+    status: TransactionStatus
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+    completed_at: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True
+
+
+class Transaction(TransactionInDBBase):
+    """Response model for transaction data"""
+    pass

app/schemas/user.py

@@ -0,0 +1,41 @@
+from pydantic import BaseModel, EmailStr, Field
+from typing import Optional
+from datetime import datetime
+
+
+class UserBase(BaseModel):
+    email: EmailStr
+    first_name: str = Field(..., min_length=1, max_length=100)
+    last_name: str = Field(..., min_length=1, max_length=100)
+    is_active: Optional[bool] = True
+
+
+class UserCreate(UserBase):
+    password: str = Field(..., min_length=8)
+
+
+class UserUpdate(BaseModel):
+    email: Optional[EmailStr] = None
+    first_name: Optional[str] = Field(None, min_length=1, max_length=100)
+    last_name: Optional[str] = Field(None, min_length=1, max_length=100)
+    is_active: Optional[bool] = None
+    password: Optional[str] = Field(None, min_length=8)
+
+
+class UserInDBBase(UserBase):
+    id: int
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True
+
+
+class User(UserInDBBase):
+    """Response model for user without sensitive data"""
+    pass
+
+
+class UserInDB(UserInDBBase):
+    """Model with password hash for internal use"""
+    hashed_password: str

main.py

@@ -0,0 +1,61 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.openapi.utils import get_openapi
+
+from app.api.v1 import api_router
+from app.core.config import settings
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    description=settings.PROJECT_DESCRIPTION,
+    version=settings.VERSION,
+    openapi_url="/openapi.json",
+    docs_url="/docs",
+    redoc_url="/redoc",
+)
+
+# Set up CORS middleware
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include API router
+app.include_router(api_router, prefix="/api/v1")
+
+
+@app.get("/")
+def root():
+    """Root endpoint that returns basic information about the API."""
+    return {
+        "name": settings.PROJECT_NAME,
+        "description": settings.PROJECT_DESCRIPTION,
+        "version": settings.VERSION,
+        "documentation": "/docs",
+        "redoc": "/redoc",
+        "health_check": "/api/v1/health",
+    }
+
+
+def custom_openapi():
+    if app.openapi_schema:
+        return app.openapi_schema
+    openapi_schema = get_openapi(
+        title=settings.PROJECT_NAME,
+        version=settings.VERSION,
+        description=settings.PROJECT_DESCRIPTION,
+        routes=app.routes,
+    )
+    app.openapi_schema = openapi_schema
+    return app.openapi_schema
+
+
+app.openapi = custom_openapi
+
+if __name__ == "__main__":
+    import uvicorn
+
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/env.py

@@ -0,0 +1,83 @@
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+
+from alembic import context
+
+# Import the models for Alembic migrations
+from app.db.base import Base
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+target_metadata = Base.metadata
+
+# other values from the config, defined by the needs of env.py,
+# can be acquired:
+# my_important_option = config.get_main_option("my_important_option")
+# ... etc.
+
+
+def run_migrations_offline():
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+        render_as_batch=True,  # Important for SQLite
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online():
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        is_sqlite = connection.dialect.name == "sqlite"
+        
+        context.configure(
+            connection=connection,
+            target_metadata=target_metadata,
+            render_as_batch=is_sqlite,  # Important for SQLite
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

migrations/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

migrations/versions/f86c03d2e03d_initial_migration.py

@@ -0,0 +1,118 @@
+"""Initial migration
+
+Revision ID: f86c03d2e03d
+Revises: 
+Create Date: 2023-06-01 12:00:00.000000
+
+"""
+from alembic import op
+import sqlalchemy as sa
+import enum
+
+
+# revision identifiers, used by Alembic.
+revision = 'f86c03d2e03d'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+# Enums for account and transaction tables
+class AccountType(str, enum.Enum):
+    SAVINGS = "savings"
+    CHECKING = "checking"
+    INVESTMENT = "investment"
+
+
+class TransactionType(str, enum.Enum):
+    DEPOSIT = "deposit"
+    WITHDRAWAL = "withdrawal"
+    TRANSFER = "transfer"
+
+
+class TransactionStatus(str, enum.Enum):
+    PENDING = "pending"
+    COMPLETED = "completed"
+    FAILED = "failed"
+    CANCELLED = "cancelled"
+
+
+def upgrade():
+    # Create users table
+    op.create_table(
+        'users',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('email', sa.String(), nullable=False),
+        sa.Column('first_name', sa.String(), nullable=False),
+        sa.Column('last_name', sa.String(), nullable=False),
+        sa.Column('hashed_password', sa.String(), nullable=False),
+        sa.Column('is_active', sa.Boolean(), nullable=True, default=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)')),
+        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=True),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_users_email'), 'users', ['email'], unique=True)
+    op.create_index(op.f('ix_users_id'), 'users', ['id'], unique=False)
+    
+    # Create accounts table
+    op.create_table(
+        'accounts',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('account_number', sa.String(), nullable=False),
+        sa.Column('owner_id', sa.Integer(), nullable=False),
+        sa.Column('account_type', sa.Enum('savings', 'checking', 'investment', name='accounttype'), nullable=False),
+        sa.Column('balance', sa.Float(), nullable=False, default=0.0),
+        sa.Column('currency', sa.String(), nullable=False, default='USD'),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)')),
+        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=True),
+        sa.ForeignKeyConstraint(['owner_id'], ['users.id'], ),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_accounts_account_number'), 'accounts', ['account_number'], unique=True)
+    op.create_index(op.f('ix_accounts_id'), 'accounts', ['id'], unique=False)
+    
+    # Create transactions table
+    op.create_table(
+        'transactions',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('transaction_reference', sa.String(), nullable=False),
+        sa.Column('sender_id', sa.Integer(), nullable=True),
+        sa.Column('sender_account_id', sa.Integer(), nullable=True),
+        sa.Column('receiver_id', sa.Integer(), nullable=True),
+        sa.Column('receiver_account_id', sa.Integer(), nullable=True),
+        sa.Column('amount', sa.Float(), nullable=False),
+        sa.Column('currency', sa.String(), nullable=False, default='USD'),
+        sa.Column('transaction_type', sa.Enum('deposit', 'withdrawal', 'transfer', name='transactiontype'), nullable=False),
+        sa.Column('status', sa.Enum('pending', 'completed', 'failed', 'cancelled', name='transactionstatus'), nullable=False, default='pending'),
+        sa.Column('description', sa.String(), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)')),
+        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=True),
+        sa.Column('completed_at', sa.DateTime(timezone=True), nullable=True),
+        sa.ForeignKeyConstraint(['receiver_account_id'], ['accounts.id'], ),
+        sa.ForeignKeyConstraint(['receiver_id'], ['users.id'], ),
+        sa.ForeignKeyConstraint(['sender_account_id'], ['accounts.id'], ),
+        sa.ForeignKeyConstraint(['sender_id'], ['users.id'], ),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_transactions_id'), 'transactions', ['id'], unique=False)
+    op.create_index(op.f('ix_transactions_transaction_reference'), 'transactions', ['transaction_reference'], unique=True)
+
+
+def downgrade():
+    # Drop tables in reverse order
+    op.drop_index(op.f('ix_transactions_transaction_reference'), table_name='transactions')
+    op.drop_index(op.f('ix_transactions_id'), table_name='transactions')
+    op.drop_table('transactions')
+    
+    op.drop_index(op.f('ix_accounts_id'), table_name='accounts')
+    op.drop_index(op.f('ix_accounts_account_number'), table_name='accounts')
+    op.drop_table('accounts')
+    
+    op.drop_index(op.f('ix_users_id'), table_name='users')
+    op.drop_index(op.f('ix_users_email'), table_name='users')
+    op.drop_table('users')
+    
+    # Drop enum types
+    sa.Enum(name='transactionstatus').drop(op.get_bind(), checkfirst=False)
+    sa.Enum(name='transactiontype').drop(op.get_bind(), checkfirst=False)
+    sa.Enum(name='accounttype').drop(op.get_bind(), checkfirst=False)

requirements.txt

@@ -0,0 +1,11 @@
+fastapi>=0.100.0
+uvicorn>=0.22.0
+pydantic>=2.0.0
+pydantic-settings>=2.0.0
+sqlalchemy>=2.0.0
+alembic>=1.11.1
+python-jose[cryptography]>=3.3.0
+passlib[bcrypt]>=1.7.4
+python-multipart>=0.0.6
+ruff>=0.0.272
+python-dotenv>=1.0.0