💲 leggen

An Open Banking CLI and API service for managing bank connections and transactions.

This tool provides FastAPI backend service (leggend), a React Web Interface and a command-line interface (leggen) to connect to banks using the GoCardless Open Banking API.

Having your bank data accessible through both CLI and REST API gives you the power to backup, analyze, create reports, and integrate with other applications.

🛠️ Technologies

🔌 API & Backend

• FastAPI: High-performance async API backend (leggend service)
• GoCardless Open Banking API: for connecting to banks
• APScheduler: Background job scheduling with configurable cron

📦 Storage

• SQLite: for storing transactions, simple and easy to use

Frontend

• React: Modern web interface with TypeScript
• Vite: Fast build tool and development server
• Tailwind CSS: Utility-first CSS framework
• TanStack Query: Powerful data synchronization for React

✨ Features

🎯 Core Banking Features

• Connect to banks using GoCardless Open Banking API (30+ EU countries)
• List all connected banks and their connection statuses
• View balances of all connected accounts
• List and filter transactions across all accounts
• Support for both booked and pending transactions

🔄 Data Management

• Sync all transactions with SQLite database
• Background sync scheduling with configurable cron expressions
• Automatic transaction deduplication and status tracking
• Real-time sync status monitoring

📡 API & Integration

• REST API: Complete FastAPI backend with comprehensive endpoints
• CLI Interface: Enhanced command-line tools with new options

🔔 Notifications & Monitoring

• Discord and Telegram notifications for filtered transactions
• Configurable transaction filters (case-sensitive/insensitive)
• Account expiry notifications and status alerts
• Comprehensive logging and error handling

🚀 Quick Start

Prerequisites

1. Create a GoCardless account at https://gocardless.com/bank-account-data/
2. Get your API credentials (key and secret)

Installation Options

Option 1: Docker Compose (Recommended)

The easiest way to get started is with Docker Compose, which includes both the React frontend and FastAPI backend:

# Clone the repository
git clone https://github.com/elisiariocouto/leggen.git
cd leggen

# Create your configuration
mkdir -p leggen && cp config.example.toml leggen/config.toml
# Edit leggen/config.toml with your GoCardless credentials

# Start all services (frontend + backend)
docker compose up -d

# Access the web interface at http://localhost:3000
# API is available at http://localhost:8000

Option 2: Local Development

For development or local installation:

# Install with uv (recommended) or pip
uv sync  # or pip install -e .

# Start the API service
uv run leggend --reload  # Development mode with auto-reload

# Use the CLI (in another terminal)
uv run leggen --help

Configuration

Create a configuration file at ~/.config/leggen/config.toml:

[gocardless]
key = "your-api-key"
secret = "your-secret-key"
url = "https://bankaccountdata.gocardless.com/api/v2"

[database]
sqlite = true

# Optional: Background sync scheduling
[scheduler.sync]
enabled = true
hour = 3      # 3 AM
minute = 0
# cron = "0 3 * * *"  # Alternative: use cron expression

# Optional: Discord notifications
[notifications.discord]
webhook = "https://discord.com/api/webhooks/..."
enabled = true

# Optional: Telegram notifications
[notifications.telegram]
token = "your-bot-token"
chat_id = 12345
enabled = true

# Optional: Transaction filters for notifications
[filters]
case-insensitive = ["salary", "utility"]
case-sensitive = ["SpecificStore"]

📖 Usage

API Service (leggend)

Start the FastAPI backend service:

# Production mode
leggend

# Development mode with auto-reload
leggend --reload

# Custom host and port
leggend --host 127.0.0.1 --port 8080

API Documentation: Visit http://localhost:8000/docs for interactive API documentation.

CLI Commands (leggen)

Basic Commands

# Check connection status
leggen status

# Connect to a new bank
leggen bank add

# View account balances
leggen balances

# List recent transactions
leggen transactions --limit 20

# View detailed transactions
leggen transactions --full

Sync Operations

# Start background sync
leggen sync

# Synchronous sync (wait for completion)
leggen sync --wait

# Force sync (override running sync)
leggen sync --force --wait

API Integration

# Use custom API URL
leggen --api-url http://localhost:8080 status

# Set via environment variable
export LEGGEND_API_URL=http://localhost:8080
leggen status

Docker Usage

# Start all services (frontend + backend)
docker compose up -d

# View service status
docker compose ps

# Check logs
docker compose logs frontend
docker compose logs leggend

# Access the web interface at http://localhost:3000
# API documentation at http://localhost:8000/docs

# Stop all services
docker compose down

🔌 API Endpoints

The FastAPI backend provides comprehensive REST endpoints:

Banks & Connections

• GET /api/v1/banks/institutions?country=PT - List available banks
• POST /api/v1/banks/connect - Create bank connection
• GET /api/v1/banks/status - Connection status
• GET /api/v1/banks/countries - Supported countries

Accounts & Balances

• GET /api/v1/accounts - List all accounts
• GET /api/v1/accounts/{id} - Account details
• GET /api/v1/accounts/{id}/balances - Account balances
• GET /api/v1/accounts/{id}/transactions - Account transactions

Transactions

• GET /api/v1/transactions - All transactions with filtering
• GET /api/v1/transactions/stats - Transaction statistics

Sync & Scheduling

• POST /api/v1/sync - Trigger background sync
• POST /api/v1/sync/now - Synchronous sync
• GET /api/v1/sync/status - Sync status
• GET/PUT /api/v1/sync/scheduler - Scheduler configuration

Notifications

• GET/PUT /api/v1/notifications/settings - Manage notifications
• POST /api/v1/notifications/test - Test notifications

🛠️ Development

Local Development Setup

# Clone and setup
git clone https://github.com/elisiariocouto/leggen.git
cd leggen

# Install dependencies
uv sync

# Start API service with auto-reload
uv run leggend --reload

# Use CLI commands
uv run leggen status

Testing

Run the comprehensive test suite with:

# Run all tests
uv run pytest

# Run unit tests only
uv run pytest tests/unit/

# Run with verbose output
uv run pytest tests/unit/ -v

# Run specific test files
uv run pytest tests/unit/test_config.py -v
uv run pytest tests/unit/test_scheduler.py -v
uv run pytest tests/unit/test_api_banks.py -v

# Run tests by markers
uv run pytest -m unit      # Unit tests
uv run pytest -m api       # API endpoint tests
uv run pytest -m cli       # CLI tests

The test suite includes:

• Configuration management tests - TOML config loading/saving
• API endpoint tests - FastAPI route testing with mocked dependencies
• CLI API client tests - HTTP client integration testing
• Background scheduler tests - APScheduler job management
• Mock data and fixtures - Realistic test data for banks, accounts, transactions

Code Structure

leggen/              # CLI application
├── commands/        # CLI command implementations
├── utils/           # Shared utilities
└── api_client.py    # API client for leggend service

leggend/             # FastAPI backend service
├── api/             # API routes and models
├── services/        # Business logic
├── background/      # Background job scheduler
└── main.py          # FastAPI application

tests/               # Test suite
├── conftest.py      # Shared test fixtures
└── unit/            # Unit tests
    ├── test_config.py      # Configuration tests
    ├── test_scheduler.py   # Background scheduler tests
    ├── test_api_banks.py   # Banks API tests
    ├── test_api_accounts.py # Accounts API tests
    └── test_api_client.py  # CLI API client tests

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes with tests
4. Submit a pull request

⚠️ Notes

• This project is in active development
• GoCardless API rate limits apply
• Some banks may require additional authorization steps
• Docker images are automatically built and published on releases