building-with-base-account

Original：🇺🇸 English

Translated

Integrates Base Account SDK for authentication and payments. Covers Sign in with Base (SIWB), Base Pay, Paymasters, Sub Accounts, Spend Permissions, Prolinks, and batch transactions. Use when building apps with wallet authentication, USDC payments, sponsored transactions, smart wallet features, recurring subscriptions, shareable payment links, or any onchain interaction on Base. Covers phrases like "add sign in with Base", "SIWB button", "accept USDC payments", "Base Pay", "paymaster setup", "gas sponsorship", "smart wallet", "sub account", "spend permissions", or "payment link".

2installs

Sourcebase/skills

Added on2026-02-25

NPX Install

npx skill4agent add base/skills building-with-base-account

SKILL.md Content

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Building with Base Account

Base Account is an ERC-4337 smart wallet providing universal sign-on, one-tap USDC payments, and multi-chain support (Base, Arbitrum, Optimism, Zora, Polygon, BNB, Avalanche, Lordchain, Ethereum Mainnet).

Quick Start

bash

npm install @base-org/account @base-org/account-ui

typescript

import { createBaseAccountSDK } from '@base-org/account';

const sdk = createBaseAccountSDK({
  appName: 'My App',
  appLogoUrl: 'https://example.com/logo.png',
  appChainIds: [8453], // Base Mainnet
});

const provider = sdk.getProvider();

Feature References

Read the reference for the feature you're implementing:

Feature	Reference	When to Read
Sign in with Base	references/authentication.md	Wallet auth, SIWE, backend verification, SignInWithBaseButton, Wagmi/Privy setup
Base Pay	references/payments.md	One-tap USDC payments, payerInfo, server-side verification, BasePayButton
Subscriptions	references/subscriptions.md	Recurring charges, spend permissions, CDP wallet setup, charge/revoke lifecycle
Sub Accounts	references/sub-accounts.md	App-specific embedded wallets, key generation, funding
Capabilities	references/capabilities.md	Batch transactions, gas sponsorship (paymasters), atomic execution, auxiliaryFunds, attribution
Prolinks	references/prolinks.md	Shareable payment links, QR codes, encoded transaction URLs
Troubleshooting	references/troubleshooting.md	Popup issues, gas usage, unsupported calls, migration, doc links

Critical Requirements

Security

Track transaction IDs to prevent replay attacks
Verify sender matches authenticated user to prevent impersonation
Use a proxy to protect Paymaster URLs from frontend exposure
Paymaster providers must be ERC-7677-compliant
Never expose CDP credentials client-side (subscription backend only)

Popup Handling

Generate nonces before user clicks "Sign in" to avoid popup blockers

Use

Cross-Origin-Opener-Policy: same-origin-allow-popups

```
same-origin
```
breaks the Base Account popup

Base Pay

Base Pay works independently from SIWB — no auth required for
```
pay()
```
```
testnet
```
param in
```
getPaymentStatus()
```
must match
```
pay()
```
call
Never disable actions based on onchain balance alone — check
```
auxiliaryFunds
```
capability

Sub Accounts

Call
```
wallet_addSubAccount
```
each session before use
Ownership changes expected on new devices/browsers
Only Coinbase Smart Wallet contracts supported for import

Smart Wallets

ERC-6492 wrapper enables signature verification before wallet deployment
Viem's
```
verifyMessage
```
/
```
verifyTypedData
```
handle this automatically

For Edge Cases and Latest API Changes

AI-optimized docs: docs.base.org/llms.txt
Full reference: docs.base.org/base-account