One-Time Secret Sharing Service

A secure API backend for a one-time secret sharing service built with FastAPI and SQLite.

Features

• Create and share secrets securely
• Secrets can only be viewed once
• Automatic deletion after viewing or expiration
• Customizable time-to-live (TTL) for secrets
• Background cleanup of expired secrets
• Encrypted storage of secrets

API Endpoints

Health Check

GET /health

Returns the health status of the API and database connection.

Create a Secret

POST /api/v1/secrets

Create a new secret and get a token to access it.

Request Body:

{
  "content": "Your secret message here",
  "ttl_hours": 24  // Optional, defaults to 24 hours
}

Response:

{
  "token": "unique-token-id",
  "expires_at": "2023-07-28T10:00:00.000Z",
  "message": "Secret stored successfully"
}

Retrieve a Secret

GET /api/v1/secrets/{token}

Retrieve a secret using its token. The secret is deleted immediately after retrieval.

Response:

{
  "content": "Your secret message here",
  "message": "Secret retrieved successfully"
}

Error Responses:

• 404 Not Found - Secret not found, already viewed, or expired

Setup and Installation

Prerequisites

• Python 3.8+
• SQLite

Environment Variables

The application uses the following environment variables:

• SECRET_KEY: Secret key for encryption (defaults to "development_secret_key" in development)

Environment Detection

The application automatically detects the environment it's running in:

• In local development, it uses the project directory for database storage
• In container deployment, it uses the /app/storage/db directory
• Database permissions are automatically set to ensure write access

Installation

1. Clone the repository
2. Create a virtual environment and activate it:

   python -m venv venv
   source venv/bin/activate  # On Windows: venv\Scripts\activate
   

3. Install dependencies:

   pip install -r requirements.txt
   

Database Setup

Run Alembic migrations to set up the database:

alembic upgrade head

The SQLite database will be created automatically in the storage/db directory with the proper permissions. The application will ensure that both the directory and the database file have appropriate write permissions.

Running the Application

Start the application with uvicorn:

uvicorn main:app --host 0.0.0.0 --port 8000 --reload

The API will be available at http://localhost:8000.

• API Documentation: http://localhost:8000/docs
• ReDoc Documentation: http://localhost:8000/redoc
• OpenAPI Specification: http://localhost:8000/openapi.json

Security Considerations

• Secrets are encrypted before storage
• Secrets are automatically deleted after viewing
• Expired secrets are cleaned up regularly
• The service uses a TTL (time-to-live) mechanism to ensure secrets don't persist indefinitely

Development

Project Structure

.
├── alembic.ini                  # Alembic configuration
├── app/                         # Application code
│   ├── api/                     # API endpoints
│   │   └── routes/              # Route definitions
│   ├── core/                    # Core application code
│   │   └── config.py            # Application configuration
│   ├── db/                      # Database related code
│   │   └── session.py           # Database session setup
│   ├── models/                  # SQLAlchemy models
│   │   ├── base.py              # Base model
│   │   └── secret.py            # Secret model
│   ├── schemas/                 # Pydantic schemas
│   │   └── secret.py            # Secret schemas
│   └── services/                # Business logic
│       ├── encryption.py        # Encryption service
│       └── secret_service.py    # Secret service
├── main.py                      # Application entry point
├── migrations/                  # Alembic migrations
│   └── versions/                # Migration scripts
├── README.md                    # This file
└── requirements.txt             # Python dependencies