Onchain SMS

Public wallet notes on Robinhood Chain and Base. Each send is one EVM transaction that:

1. pays a small ETH fee to the treasury; and
2. embeds the recipient and message in calldata.

Firebase authenticates wallets and indexes confirmed txs for inbox and sent views. The chain is the source of truth; Firebase is an index.

Messages are public. Do not post secrets or personal data.

Architecture

• Wagmi connects MetaMask, Rabby, Robinhood Wallet, and WalletConnect wallets.
• A signed nonce proves ownership and becomes the Firebase Auth UID (lowercase address).
• The browser submits one tx with the 0.00025 ETH fee and encoded message.
• A Cloud Function checks the receipt, sender, treasury, fee, chain, and payload.
• Firestore stores only verified txs and rejects hash reuse.
• Clients read Firestore; only Admin SDK Cloud Functions write index entries.

Configuration

Copy .env.example to .env.local and set Firebase web config, Reown project ID, treasury, and fee:

VITE_REOWN_PROJECT_ID=
VITE_FIREBASE_API_KEY=
VITE_FIREBASE_AUTH_DOMAIN=
VITE_FIREBASE_PROJECT_ID=
VITE_FIREBASE_STORAGE_BUCKET=
VITE_FIREBASE_MESSAGING_SENDER_ID=
VITE_FIREBASE_APP_ID=
VITE_TREASURY_ADDRESS=0x...
VITE_MESSAGE_FEE_ETH=0.00025

Copy functions/.env.example to functions/.env.<firebase-project-id>:

TREASURY_ADDRESS=0x...
MESSAGE_FEE_ETH_WEI=250000000000000
ROBINHOOD_RPC_URL=https://your-production-rpc
BASE_RPC_URL=https://your-production-rpc

Deploy:

npm run build
firebase deploy --only functions,firestore,hosting

Development

npm install
npm install --prefix functions
npm run dev

Network	Chain ID	Explorer
Robinhood Chain	4663	https://robinhoodchain.blockscout.com
Base	8453	https://base.blockscout.com