> For the complete documentation index, see [llms.txt](https://developers-apps-in-toss.toss.im/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers-apps-in-toss.toss.im/documentation/api-and-sdk-en/sdk/domains-api/tosspay/tosspay.authorize.md).

# TossPay.authorize

> Functional API `checkoutPayment`You can use the same functionality with the function-style API as well. The function-style API is the same as v2 `{ params: { payToken } }` It takes arguments in the form of.

### Feature description

It opens the Toss Pay payment window and performs user authentication. When authentication is complete, it returns whether it was successful.

Actual payment approval is done on the server `payToken`must be handled separately with.

### Type

```ts
TossPay.authorize(params: CheckoutPaymentOptions): Promise<CheckoutPaymentResult>;
```

**Params**

```ts
type CheckoutPaymentOptions = {
  /** Payment token. */
  payToken: string;
};
```

**Response**

```ts
type CheckoutPaymentResult = {
  /** Whether authentication succeeded. */
  success: boolean;
  /** The reason if authentication failed. */
  reason?: string;
};
```

### Example code

```js
import { TossPay } from "@apps-in-toss/web-framework";

async function handlePayment() {
  try {
    // Replace this with the API endpoint that creates the payment in the actual implementation.
    const { payToken } = await fetch("/my-api/payment/create").then((res) =>
      res.json(),
    );

    const { success, reason } = await TossPay.authorize({ payToken });

    if (success) {
      // Replace this with the API endpoint that executes the payment in the actual implementation.
      await fetch("/my-api/payment/execute", {
        method: "POST",
        body: JSON.stringify({ payToken }),
        headers: { "Content-Type": "application/json" },
      });
    } else {
      console.log("Authentication failed:", reason);
    }
  } catch (error) {
    console.error("An error occurred during payment authentication:", error);
  }
}

document.querySelector("#pay-button").addEventListener("click", handlePayment);
```


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