build-on-base

name

build-on-base

description

Complete Base development playbook. Covers: (1) Network — Base RPC URLs, chain IDs (8453/84532), explorer config, testnet setup, connect to Base, Base Sepolia; (2) Contracts — Foundry deployment, forge create, BaseScan verification, CDP faucet, testnet ETH, deploy contract to Base; (3) Builder Codes — ERC-8021 attribution suffix, referral fees, dataSuffix for Wagmi/Viem/Privy/ ethers.js/window.ethereum, transaction attribution, earn referral fees, append builder code; (4) Base Account SDK — Sign in with Base (SIWB), Base Pay, USDC payments, paymasters, gas sponsorship, sub-accounts, spend permissions, prolinks, batch transactions, smart wallet, payment link, recurring subscription; (5) Agent registration — trading bots, AI agents, automated senders, ERC-8021 attribution wiring, base.dev API, register agent, builder code registration; (6) Node operation — run Base node, Reth setup, hardware requirements, self-hosted RPC, sync; (7) Migrations — migrate OnchainKit, OnchainKitProvider to WagmiProvider, wagmi migration, remove onchainkit dependency, MiniKit to Farcaster SDK, convert miniapp, Farcaster miniapp to regular app, convert Farcaster miniapp.

Base Development

Complete playbook for building on Base L2 — network setup, smart contracts, wallet auth, payments, developer tool attribution, and framework migrations.

Default Stack

Layer	Default
Network	Base Mainnet (8453) / Base Sepolia testnet (84532)
Contracts	Foundry (forge create + BaseScan verification)
Wallet auth	Base Account SDK (@base-org/account)
Payments	Base Pay — USDC, gasless, settles in <2s
Transactions	wagmi + viem
Attribution	Builder Codes — ERC-8021 via ox/erc8021
RPC (prod)	Dedicated node provider or self-hosted Reth

Safety Guardrails

• Never commit private keys — use cast wallet import for Foundry keystores
• Never expose RPC API keys or CDP credentials client-side — proxy through backend
• Never skip server-side payment verification — always call getPaymentStatus() server-side and verify sender, amount, recipient; track processed tx IDs to prevent replay attacks
• Never send transactions without Builder Code attribution — silent data loss, no errors, no warnings
• Validate all user-provided shell inputs before constructing forge/cast commands (no spaces, semicolons, pipes)
• COOP headers for Base Account popups — use same-origin-allow-popups, not same-origin

Task Routing

Read the reference for your task:

Task	When to Use	Reference
Network config	RPC URLs, chain IDs, explorer links, testnet setup	references/network.md
Deploy contracts	Foundry deployment, BaseScan verification, faucet	references/deploy-contracts.md
Run a Base node	Self-hosted RPC, Reth, hardware requirements	references/run-node.md
Builder Codes	Add ERC-8021 attribution to transactions	references/builder-codes/overview.md
Base Account SDK	SIWB, Base Pay, subscriptions, sub-accounts	references/base-account/overview.md
Register AI agent/bot	Register wallet, get builder code, wire attribution	references/agents/register.md
Migrate from OnchainKit	OnchainKitProvider → wagmi, wallet/tx components	references/migrations/onchainkit/overview.md
MiniKit → Farcaster SDK	@coinbase/onchainkit/minikit → @farcaster/miniapp-sdk	references/migrations/minikit-to-farcaster/overview.md
Farcaster miniapp → regular app	Remove Mini App host coupling, convert to Base/web app	references/migrations/farcaster-miniapp-to-app.md

Operating Procedure

1. Classify the task using the table above
2. Read the relevant reference before implementing
3. Confirm the framework with the user when multiple options exist (e.g., Privy vs wagmi for Builder Codes)
4. Implement with explicit chain ID, security requirements, and all required validations
5. Deliver diffs, install commands, and any manual steps (env vars, API key setup, wallet registration)

For Edge Cases and Latest API Changes

• AI-optimized docs: docs.base.org/llms.txt
• Base Account reference: docs.base.org/base-account
• Base chain docs: docs.base.org

Installation

npx skills add base/skills --skill build-on-base