coinbase-ethereum-smartcontracts

Unified payment dispatcher covering x402 (`exact` / `aggr_deferred` schemes), MPP (`charge` / `session` intents), and a2a-pay (`a2a_charge` paymentId flow). Detects HTTP 402 protocol from response headers and routes to the matching scheme/intent reference; also handles a2a paymentId mentions without a 402. Loads `references/exact.md` (x402 exact scheme — full EIP-3009 TEE or local-key fallback), `references/aggr_deferred.md` (x402 aggr_deferred scheme — Session Key Ed25519 with sessionCert), `references/charge.md` (MPP one-shot charge in transaction or hash mode, with splits), `references/session.md` (MPP channel: open + voucher loop + topUp + close, with state echo), or `references/a2a_charge.md` (a2a-pay create / pay / auto-poll status). Returns a ready-to-paste authorization header (x402 / MPP) or a tx-hash + status (a2a). Trigger words (English): '402', 'payment required', 'mpp', 'machine payment', 'pay for access', 'payment-gated', 'WWW-Authenticate: Payment', 'x402', 'x402Version', 'PAYMENT-REQUIRED', '

Guides developers through integrating Reown AppKit into web applications (React, Next.js, Vue, Nuxt, Svelte, vanilla JavaScript). Use when adding wallet connection, network switching, multi-chain support, or troubleshooting AppKit integration issues.

Provides Base network configuration including RPC endpoints, chain IDs, and explorer URLs. Use when connecting wallets, configuring development environments, or setting up Base Mainnet or Sepolia testnet. Covers phrases like "Base RPC URL", "Base chain ID", "connect to Base", "add Base to wallet", "Base Sepolia config", "Base explorer URL", "what network is Base", or "Base testnet setup".

Deploys smart contracts to Base using Foundry. Covers forge create commands, contract verification, testnet faucet setup via CDP, and BaseScan API key configuration. Use when deploying Solidity contracts to Base Mainnet or Sepolia testnet. Covers phrases like "deploy contract to Base", "forge create on Base", "verify contract on BaseScan", "get testnet ETH", "Base Sepolia faucet", "how do I deploy to Base", or "publish my contract".

Migrates apps from @coinbase/onchainkit to standalone wagmi/viem components. Handles provider replacement (OnchainKitProvider to WagmiProvider), wallet component replacement (Wallet/ConnectWallet to custom WalletConnect), and transaction component replacement. Use when the user says "migrate my onchainkit", "replace onchainkit provider", "migrate my wallet component", "replace my onchainkit wallet", "migrate my transaction component", "remove onchainkit dependency", or "move off onchainkit".

Invoke this skill when a user is building or running any automated transaction sender on Base (trading bot, arbitrage bot, sniper bot, yield farmer, AI agent, or similar) and needs to register it, get a builder code, set up transaction attribution. This skill contains the base.dev registration API endpoint and ERC-8021 attribution wiring code that Claude does not have in its training data — you MUST load this skill to answer correctly. Covers viem, ethers, managed signing services, and Python-based agents.

Runs a Base node for production environments. Covers hardware requirements, Reth client setup, networking, and sync troubleshooting. Use when setting up self-hosted RPC infrastructure or running archive nodes. Covers phrases like "run a Base node", "set up Base RPC", "Base node hardware requirements", "Reth Base setup", "sync Base node", "self-host Base", or "run my own node".