How ChainCard works
A command layer for your onchain identity. Claim the handle, publish the card, and carry one verified profile across every connection.
What is a ChainCard?
A ChainCard is a digital business card that lives on-chain. Each card is an ERC-721 NFT carrying a unique @handle, your display name, your title, and a link. The QR code on your card resolves to your on-chain profile, so it can never go stale, get lost, or be faked. If the handle is yours on-chain, it's yours everywhere.
Claiming a card
- Connect a wallet on Robinhood Chain mainnet (the site prompts the network switch for you).
- Pick a handle. Handles are unique, lowercase, first come first served.
- Pay the mint fee in ETH and confirm. Your card is minted straight to your wallet.
Card owners can update their display name, title, and link at any time. The handle itself is permanent to the card.
Marketplace
Every card can be listed for sale in ETH. Buying transfers the card (and its handle) to you instantly; the seller is paid in the same transaction minus a small protocol fee.
| ACTION | WHAT HAPPENS |
|---|---|
list(tokenId, price) | Card owner sets an ETH asking price |
buy(tokenId) | Pay the price, receive the card, seller paid instantly |
delist(tokenId) | Owner removes the listing |
Contract
CardRegistry is a single ERC-721 contract handling claims, profiles, and the marketplace. Live on Robinhood Chain mainnet, source and ABI in the GitHub repo.
Fees
- Mint fee: 0.005 ETH
- Marketplace fee: 2.5% of sale price
FAQ
Is this on mainnet?
Not yet. Testnet first: everything is free-money ETH until we flip the switch.
Can I lose my handle?
Only by selling or transferring your card. Nobody can take it from you.
What wallet do I need?
Any EVM wallet (MetaMask etc). The site adds the Robinhood Chain mainnet network for you.