ethdca

Making automated DCA accessible to everyone as a public good.

How It Works

1. Fund wallet with USDC via Coinbase Apple Pay
2. Start DCA - Balance is divided over 52 weeks
3. First swap executes immediately, then weekly on Mondays at 12pm UTC
4. Add USDC anytime - Weekly amount auto-adjusts

Weekly Amount: currentBalance / remainingWeeks

Technical Architecture

Privy Session Signers

User-authorized server keys enable gasless automated swaps without requiring signatures for each transaction:

1. User logs in and authorizes a session signer
2. Server stores authorization key (PRIVY_AUTHORIZATION_PRIVATE_KEY)
3. Cron job uses this key to execute swaps on user's behalf
4. All transactions are gas-sponsored by Privy

Result: True automation - no approval needed for weekly swaps.

0x Swap Aggregation

Each swap routes through 0x Protocol for best execution:

1. Cron fetches quote for USDC → ETH swap
2. 0x aggregates liquidity across all Base DEXes
3. Returns optimized route with best price
4. Executes via 0x's AllowanceHolder contract

Result: Best available price across Uniswap, Curve, and other DEXes.

Infrastructure

• Vercel KV - Redis storage for DCA schedules
• Vercel Cron - Weekly execution (Mondays 12pm UTC)
• Base L2 - Low fees, fast finality

Deployment

1. Create Vercel KV Database

Go to Vercel project → Storage → Create Database → Select "KV"

2. Environment Variables

NEXT_PUBLIC_PRIVY_APP_ID=your_privy_app_id
PRIVY_APP_SECRET=your_privy_app_secret
PRIVY_AUTHORIZATION_PRIVATE_KEY=your_privy_auth_key
ZEROX_API_KEY=your_0x_api_key
CRON_SECRET=$(openssl rand -base64 32)

Vercel KV variables are auto-added when you create the database.

3. Deploy

npm install
npm run build

Deploy to Vercel and the cron job will automatically run weekly.

Stack

• Next.js 16 - React framework
• Privy - Embedded wallets + session signers
• 0x Protocol - DEX aggregation
• Vercel - Hosting + cron + KV storage
• Base - L2 network
• viem - Ethereum interactions

Contributing

This is a public good project. Contributions welcome!

License

MIT