> ## Documentation Index
> Fetch the complete documentation index at: https://docs.x402x.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Fetch parameters

> Inputs for wrapFetchWithPayment

## Signature

```ts theme={null}
wrapFetchWithPayment(
  fetch: typeof globalThis.fetch,
  walletClient: WalletClient,
  maxValue?: string,
  paymentRequirementsSelector?: (r402: Response402) => PaymentRequirements
): typeof globalThis.fetch
```

## Notes

* `maxValue`: the maximum allowed payable amount (strongly recommended)
* `paymentRequirementsSelector`: custom selector for requirements

## Full signature and types

```ts theme={null}
import type { WalletClient } from "viem";

type PaymentRequirementsSelector = (
  requirements: PaymentRequirements[],
  network?: string[],
  scheme?: string
) => PaymentRequirements;

interface X402Config {
  svmConfig?: {
    rpcUrl?: string;
  };
  evmConfig?: {
    rpcUrls?: Record<number, string>;
  };
}

wrapFetchWithPayment(
  fetch: typeof globalThis.fetch,
  walletClient: WalletClient,
  maxValue?: bigint,
  paymentRequirementsSelector?: PaymentRequirementsSelector,
  config?: X402Config
): typeof globalThis.fetch;
```

> Tip: choose a conservative default for `maxValue`; in production, set it explicitly to prevent excessive payments.