Stablecoin Supply API

A FastAPI-based service for collecting and serving stablecoin circulating supply data from DeFiLlama.

Features

• Collects stablecoin supply data from DeFiLlama
• Stores data in PostgreSQL database with UTC timestamps
• Provides REST API endpoints for accessing the data
• Supports filtering by stablecoin symbol and chain
• Tracks supply changes over 24h, 7d, and 30d periods

Setup

1. Prerequisites

• Python 3.8 or higher
• PostgreSQL 12 or higher
• psql command-line tool

2. Database Setup

# Create PostgreSQL database
createdb stables

3. Python Environment

# Create virtual environment
python -m venv venv

# Activate virtual environment
source venv/bin/activate  # On Windows: venv\Scripts\activate

# Install dependencies
pip install -r requirements.txt

4. Environment Configuration

Create a .env file in the backend directory:

# Default configuration
DATABASE_URL=postgresql://postgres:postgres@localhost:5432/stables

5. Database Migration

# Initialize database schema
alembic upgrade head

6. Start the Server

# Development mode with auto-reload
uvicorn app.main:app --reload

# Production mode
uvicorn app.main:app --host 0.0.0.0 --port 8000

Database Schema

Stablecoin Table

• id: Primary key (from DeFiLlama)
• name: Stablecoin name
• symbol: Token symbol (indexed)
• gecko_id: CoinGecko ID (indexed)
• peg_type: Type of peg (e.g., USD, EUR)
• peg_mechanism: Peg mechanism type
• total_circulating: Total supply across all chains
• time_utc: Timestamp with minute precision

Chain Circulating Table

• Composite primary key: (stable_id, chain, time_utc)
• stable_id: Foreign key to stablecoin table
• chain: Blockchain name
• circulating: Circulating supply on this chain
• time_utc: Timestamp with minute precision

API Endpoints

• GET /: Root endpoint with API information
• GET /supply: Get circulating supply data
  • Query parameters:
    • symbol: Filter by stablecoin symbol
    • chain: Filter by chain
    • limit: Maximum number of records (default: 100)
• POST /collect: Trigger data collection from DeFiLlama

Development

Database Migrations

# Create a new migration
alembic revision --autogenerate -m "description"

# Apply migrations
alembic upgrade head

# Rollback one version
alembic downgrade -1

Code Style

The project follows PEP 8 guidelines. Before committing:

# Install development dependencies
pip install black isort

# Format code
black .
isort .