Backend Setup

Guide for setting up and running the QsnDEX Rust backend locally.

Prerequisites

• Rust 1.75 or later (install via rustup)
• PostgreSQL 16
• Redis 7

Environment Configuration

Copy the example environment file and fill in the required values:

cp .env.example .env

Required environment variables:

Variable	Description
DATABASE_URL	PostgreSQL connection string (e.g., postgres://user:pass@localhost:5432/qsndex)
REDIS_URL	Redis connection string (e.g., redis://localhost:6379)
GROQ_API_KEY	API key for Groq LLM inference
KEEPER_PRIVATE_KEY	Private key for keeper operations (limit orders, alerts)
TAIKO_RPC_URL	Taiko mainnet RPC endpoint
ARB_SEPOLIA_RPC_URL	Arbitrum Sepolia testnet RPC endpoint

Build

cd backend
cargo build --release

The release binary is output to target/release/.

Run

The backend.sh management script provides convenient commands:

./backend.sh build     # Build the release binary
./backend.sh start     # Start the server in the background
./backend.sh stop      # Stop the running server
./backend.sh restart   # Restart the server
./backend.sh status    # Check if the server is running
./backend.sh logs      # Tail server logs

Alternatively, run directly:

cd backend
cargo run --release

Verify

Once running, the API is available at:

• API: http://localhost:8080
• Swagger UI: http://localhost:8080/swagger-ui

Test with a simple request:

curl http://localhost:8080/api/tokens?chain_id=167000

Database Migrations

SQL migrations are located in backend/migrations/. They are applied automatically on server startup via SQLx. To run migrations manually:

cd backend
sqlx migrate run

Development Tips

• Use cargo watch -x run for automatic recompilation during development.
• Set RUST_LOG=debug for verbose logging.
• Redis must be running for rate limiting and caching to function.