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

# createX402Signature

Create x402 signature

> **Group:** Onchain APIs

Use this when you need: **Create x402 signature**.

## Usage

```ts theme={"system"}
import { NeynarAPIClient, Configuration } from "@neynar/nodejs-sdk";

const client = new NeynarAPIClient(
  new Configuration({ apiKey: "YOUR_NEYNAR_API_KEY" })
);

const res = await client.createX402Signature({
  xWalletId: "example", // Wallet ID to use for transactions
  xApiKey: "example", // required
  createX402SignatureRequest: "value", // required
});
console.log(res);
```

## Parameters

| Parameter                    | Type                         | Required | Description                       |
| ---------------------------- | ---------------------------- | :------: | --------------------------------- |
| `xWalletId`                  | `string`                     |     ✅    | Wallet ID to use for transactions |
| `xApiKey`                    | `string`                     |     ✅    | -                                 |
| `createX402SignatureRequest` | `CreateX402SignatureRequest` |     ✅    | -                                 |

## Response

Returns a `RequestArgs` object.

## Error Handling

```ts theme={"system"}
try {
  const res = await client.createX402Signature({
    xWalletId: "example",
    xApiKey: "example",
    createX402SignatureRequest: "value"
  });
  // use res
} catch (err) {
  // Axios/HTTP errors, invalid params, auth issues, etc.
  console.error(err);
}
```

## Related API Reference

📖 **API Reference:** [createX402Signature](/reference/create-x402-signature)

For detailed information about the HTTP endpoint, request/response schemas, and additional examples, see the complete API documentation.

## Tips

* Provide a **viewerFid** when supported to respect mutes/blocks and include `viewer_context`.
* Keep requests scoped (e.g., use `limit`) to improve latency.
* Cache results where sensible.