Gas Service for Arbitrum

This service monitors username changes in the Supabase database and provides gas funds to new user wallets on the Arbitrum network.

Features

• Monitors username changes in Supabase (using realtime subscriptions)
• Sends gas to new wallets (configurable amount)
• Whitelist mode for testing
• Automatic gas funding on username changes
• RPC resilience with retry mechanism
• Detailed logging
• Database tracking of funded wallets

Setup

1. Configure your environment variables in .env:

# Server
PORT=3001
LOG_LEVEL=debug # options: debug, info, warn, error

# Supabase
SUPABASE_URL=https://your-project.supabase.co
SUPABASE_KEY=your-anon-key
SUPABASE_SERVICE_ROLE_KEY=your-service-role-key

# Arbitrum RPC URL
ARBITRUM_RPC_URL=https://rpc.ankr.com/arbitrum

# Funder wallet details
FUNDER_PRIVATE_KEY=your-private-key
FUNDER_ADDRESS=your-address
GAS_AMOUNT_TO_SEND=0.001
MAX_TX_PER_MINUTE=10

# Whitelist (optional, for testing)
WHITELIST_ENABLED=true
WHITELISTED_ADDRESSES=0x123...,0x456...

2. Enable realtime for your tables in Supabase:

-- Run this in Supabase SQL Editor
DROP PUBLICATION IF EXISTS supabase_realtime;
CREATE PUBLICATION supabase_realtime FOR TABLE users, gas_tracking;
ALTER PUBLICATION supabase_realtime SET TABLE users, gas_tracking;

3. Install dependencies and build:

npm install
npm run build

Running the Service

npm start

Testing Tools

1. Manually Trigger Gas Funding

To test gas funding for a specific wallet:

cd gas-service
npx ts-node src/test-manual-trigger.ts <WALLET_ADDRESS>

This will:

• Check the target wallet's balance
• Send gas from the funder wallet
• Update the gas_tracking table
• Log detailed information about the process

2. Test Realtime Events

To verify realtime events are working:

cd gas-service
npx ts-node src/test-realtime.ts

This will set up a subscription to the users table and log all events it receives.

3. Health Check API

The service exposes a health check endpoint:

GET http://localhost:3001/health

Troubleshooting

Row-Level Security Issues

If you encounter RLS errors when updating the gas_tracking table:

1. Add your SUPABASE_SERVICE_ROLE_KEY to the .env file
2. The service will automatically retry with the service role key

Realtime Not Working

If realtime events aren't being received:

1. Verify you've run the SQL to enable realtime for your tables
2. Check the Supabase dashboard > Database > Replication to ensure your tables are listed
3. Look at the debug logs to see if the subscription has been established

Low Gas Balance

If you get an "Insufficient funder balance" error, add more ETH to your funder wallet.

Logging

Set LOG_LEVEL to control logging verbosity:

• debug: All logs (best for development)
• info: Normal operation logs (good for production)
• warn: Only warnings and errors
• error: Only errors