🐾 Capybara Petter

The onchain capybara petting competition on Base mainnet.

Pet capybaras, climb the leaderboard, become the Top Petter.

Live: capybara-petter.vercel.app

Contract: 0xe09C6b3A7390Fc24A3E07AcEF9C31AaDb883a9Ba (Base Mainnet)

What it is

A single-page dapp where every capybara pet is an onchain transaction on Base. The contract tracks per-wallet pet counts, a global pet counter, and the current Top Petter (the wallet with the most pets). Users can name their petter, climb the leaderboard, and share their pets on X and Farcaster.

The visual is loosely inspired by the yuzu onsen — capybaras are famous hot-spring soakers, so the page reads as a steamy pond with floating citrus, lily pads, and bubbles.

Features

• Onchain everything — every pet is a real transaction on Base mainnet
• Live leaderboard with Basenames resolution
• Streak tracking (local) and milestone badges (1, 10, 50, 100, 500, 1000 pets)
• Light + dark theme with prefers-color-scheme auto-detection
• Sponsored gas via Base Paymaster (EIP-5792 wallet_sendCalls) when the wallet supports it; falls back to regular eth_sendTransaction
• Multi-wallet — EIP-6963 discovery, Coinbase Smart Wallet SDK, injected fallback
• Farcaster Mini App — runs natively in Warpcast with auto-connect
• base.dev registered app
• ERC-8021 attribution wired into every transaction (builder code bc_4j84s978)
• Bottom navigation bar for mobile-friendly section jumping
• Share to X / Warpcast with one click
• No build step — single index.html, deploys to anything

Stack

• index.html — vanilla HTML/CSS/JS, no framework, no build
• CapybaraPetter.sol — Solidity 0.8.24, deployed on Base mainnet
• @farcaster/miniapp-sdk via ESM for Mini App embedding
• @coinbase/wallet-sdk via ESM for Smart Wallet support
• Direct eth_call / eth_sendTransaction / wallet_sendCalls against a public Base RPC — no wallet library
• Custom keccak256 implementation for Basenames reverse resolution

Deploy

The repo auto-deploys to Vercel on push to main.

Contract

function petCapybara() external;
function setPetterName(string calldata name) external;
function getPetterStats(address petter) external view returns (uint256 pets, string memory name, bool isTop);

License

MIT — see LICENSE.