> ## Documentation Index
> Fetch the complete documentation index at: https://docs.base.org/llms.txt
> Use this file to discover all available pages before exploring further.

# prepareSpendCallData

> Prepare calldata to approve (if needed) and spend using a Spend Permission

export const Button = ({children, disabled, variant = "primary", size = "medium", iconName, roundedFull = false, className = '', fullWidth = false, onClick = undefined}) => {
  const variantStyles = {
    primary: 'bg-blue text-black border border-blue hover:bg-blue-80 active:bg-[#06318E] dark:text-white',
    secondary: 'bg-white border border-white text-palette-foreground hover:bg-zinc-15 active:bg-zinc-30',
    outlined: 'bg-transparent text-white border border-white hover:bg-white hover:text-black active:bg-[#E3E7E9]'
  };
  const sizeStyles = {
    medium: 'text-md px-4 py-2 gap-3',
    large: 'text-lg px-6 py-4 gap-5'
  };
  const sizeIconRatio = {
    medium: '0.75rem',
    large: '1rem'
  };
  const classes = ['text-md px-4 py-2 whitespace-nowrap', 'flex items-center justify-center', 'disabled:opacity-40 disabled:pointer-events-none', 'transition-all', variantStyles[variant], sizeStyles[size], roundedFull ? 'rounded-full' : 'rounded-lg', fullWidth ? 'w-full' : 'w-auto', className];
  const buttonClasses = classes.filter(Boolean).join(' ');
  const iconSize = sizeIconRatio[size];
  return <button type="button" disabled={disabled} className={buttonClasses} onClick={onClick}>
      <span>{children}</span>
      {iconName && <Icon name={iconName} width={iconSize} height={iconSize} color="currentColor" />}
    </button>;
};

export const BaseBanner = ({content = null, id, dismissable = true}) => {
  const LOCAL_STORAGE_KEY_PREFIX = 'cb-docs-banner';
  const [isVisible, setIsVisible] = useState(false);
  const onDismiss = () => {
    localStorage.setItem(`${LOCAL_STORAGE_KEY_PREFIX}-${id}`, 'false');
    setIsVisible(false);
  };
  useEffect(() => {
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    setIsVisible(storedValue !== 'false');
  }, []);
  if (!isVisible) {
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  return <div className="fixed bottom-0 left-0 right-0 bg-white py-8 px-4 lg:px-12 z-50 text-black dark:bg-black dark:text-white border-t dark:border-gray-95">
      <div className="flex items-center max-w-8xl mx-auto">
        {typeof content === 'function' ? content({
    onDismiss
  }) : content}
        {dismissable && <button onClick={onDismiss} className="flex-shrink-0 text-gray-400 hover:text-gray-600 dark:hover:text-gray-300 transition-colors" aria-label="Dismiss banner">
          ✕
        </button>}
      </div>
    </div>;
};

Defined in the [Base Account SDK](https://github.com/base/account-sdk)

<Info>
  Returns one or two calls your app's spender can submit to execute a spend. If
  the permission is not yet registered onchain, an `approveWithSignature` call
  is prepended before the `spend` call.
</Info>

## Parameters

<ParamField body="permission" type="SpendPermission" required>
  Signed permission returned from [`requestSpendPermission`](/base-account/reference/spend-permission-utilities/requestSpendPermission) or fetched via [`fetchPermissions`](/base-account/reference/spend-permission-utilities/fetchPermissions).

  <Expandable title="SpendPermission properties">
    <ParamField body="permissionHash" type="string">
      Deterministic EIP-712 hash of the permission.
    </ParamField>

    <ParamField body="signature" type="string">
      Signature for the EIP-712 payload.
    </ParamField>

    <ParamField body="chainId" type="number">
      Target chain ID.
    </ParamField>

    <ParamField body="permission" type="object">
      Underlying permission fields.

      <Expandable title="permission fields">
        <ParamField body="account" type="address" />

        <ParamField body="spender" type="address" />

        <ParamField body="token" type="address" />

        <ParamField body="allowance" type="bigint" />

        <ParamField body="period" type="number">Duration in seconds.</ParamField>
        <ParamField body="start" type="number">Unix timestamp (seconds).</ParamField>
        <ParamField body="end" type="number">Unix timestamp (seconds).</ParamField>

        <ParamField body="salt" type="string" />

        <ParamField body="extraData" type="string" />
      </Expandable>
    </ParamField>
  </Expandable>
</ParamField>

<ParamField body="amount" type="bigint">
  Amount to spend (in wei). Omit to spend the remaining allowance.
</ParamField>

## Returns

<ResponseField name="result" type="Call[]">
  Array of calls to submit in order.

  <Expandable title="Call type">
    <ResponseField name="to" type="string" />

    <ResponseField name="data" type="`0x${string}`" />

    <ResponseField name="value" type="`0x0`" />
  </Expandable>
</ResponseField>

<RequestExample>
  ```typescript Prepare and submit spend calls theme={null}
  import { prepareSpendCallData } from "@base-org/account/spend-permission";

  const spendCalls = await prepareSpendCallData({
    permission,
    amount: 10_000n, // optional
  });

  // If supported, submit both in a batch via wallet_sendCalls
  await provider.request({
    method: "wallet_sendCalls",
    params: [
      {
        version: "2.0",
        atomicRequired: true,
        from: spender,
        calls: spendCalls,
      },
    ],
  });

  // Or submit sequentially with eth_sendTransaction
  for (const call of spendCalls) {
    await provider.request({
      method: "eth_sendTransaction",
      params: [{ ...call, from: spender }],
    });
  }
  ```
</RequestExample>

## Error Handling

Always wrap the call in a try-catch block to handle these errors gracefully.

<Info>
  Use `getPermissionStatus` to check `isActive` and `remainingSpend` before preparing a spend.
</Info>

<BaseBanner
  id="privacy-policy"
  dismissable={false}
  content={({ onDismiss }) => (
<div className="flex items-center">
  <div className="mr-2">
    We're updating the Base Privacy Policy, effective July 25, 2025, to reflect an expansion of Base services. Please review the updated policy here:{" "}
    <a
      href="https://docs.base.org/privacy-policy-2025"
      target="_blank"
      className="whitespace-nowrap"
    >
      Base Privacy Policy
    </a>. By continuing to use Base services, you confirm that you have read and understand the updated policy.
  </div>
  <Button onClick={onDismiss}>I Acknowledge</Button>
</div>
)}
/>