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

# Choose iframe or popup mode

> Decide between mounting the Onramp widget inline as an iframe or launching it in a popup window, and handle the cases where popups are blocked.

The App Kit SDK exposes two ways to mount the Onramp widget:

* `kit.onramp.mountIframe` embeds the widget as an inline `<iframe>` inside a
  container element you own. Use this when you have room in your layout for a
  720+ pixel-tall surface.
* `kit.onramp.openWindow` launches the widget as a separate popup window. Use
  this when inline embedding does not fit your UX, when iOS Safari's storage
  restrictions block the iframe flow, or when you want the widget to feel
  separate from your app.

Both are synchronous functions. Both return a widget controller you can
subscribe to. They differ in where the widget renders and in what can go wrong.

## When to pick each mode

| Situation                                               | Recommended mode |
| ------------------------------------------------------- | :--------------: |
| Default for most apps                                   |   `mountIframe`  |
| Page has no space for an inline 720px widget            |   `openWindow`   |
| Users are on iOS Safari and KYC fails inside the iframe |   `openWindow`   |
| App is installed as a PWA in standalone mode            |   `mountIframe`  |
| You need to launch the widget from a modal or drawer    |   `mountIframe`  |

iOS Safari's Intelligent Tracking Prevention can restrict storage inside a
cross-origin iframe, which sometimes breaks the embedded app's session handling.
If you see issues isolated to iOS Safari, use `openWindow` on that platform.

## Iframe mode

`mountIframe` does not require a user gesture. You can call it on page load,
from your framework's mounted lifecycle, or after any `await`. The container
element must already be attached to the document and must have an explicit,
non-zero height:

```typescript TypeScript theme={null}
const widget = kit.onramp.mountIframe({
  session,
  container: document.getElementById("onramp-root")!,
});
```

See the [quickstart](/app-kit/quickstarts/onramp-embed-widget) for an end-to-end
example.

## Popup mode

`openWindow` must be called **synchronously from a user gesture** (a click
handler, for example). If you `await` before calling, the browser blocks the
popup because the user-gesture context has expired.

Mint the session ahead of time, then call `openWindow` directly from the click
handler:

```typescript TypeScript theme={null}
import { AppKit } from "@circle-fin/app-kit";

const kit = new AppKit();

// Mint the session when the form is rendered, not on click.
const session = await kit.onramp.fetchSession({
  url: "/api/onramp/sessions",
  body: { appUserId, destinationAddress },
});

button.addEventListener("click", () => {
  const result = kit.onramp.openWindow({
    session,
    onDepositSettled: ({ payload }) => console.log("settled", payload),
  });

  if (result.status === "opened") {
    result.widget.on("DEPOSIT_NOT_COMPLETED", ({ code }) => {
      console.log("not completed", code);
    });
  }
});
```

`openWindow` returns a discriminated result rather than throwing, so a blocked
popup is a normal flow you handle in code, not an exception.

### Handle a blocked popup

When `openWindow` cannot open a usable popup, it returns
`{ status: 'blocked', reason }`. The `reason` field tells you why, and what to
do about it:

| `reason`         | Cause                                                                                         | Recommended fallback                                                                     |
| :--------------- | :-------------------------------------------------------------------------------------------- | :--------------------------------------------------------------------------------------- |
| `popup_blocked`  | The browser's popup blocker rejected the call, or an `await` ran before `openWindow`.         | Ask the user to retry from a fresh synchronous click.                                    |
| `in_app_browser` | The page is running inside an Instagram, Facebook, TikTok, LinkedIn, WeChat, or LINE WebView. | Fall back to `mountIframe`, or prompt the user to open the page in their system browser. |
| `pwa_standalone` | The page is running inside an installed PWA in standalone display mode.                       | Fall back to `mountIframe`.                                                              |

Example with all three fallbacks:

```typescript TypeScript theme={null}
button.addEventListener("click", () => {
  const result = kit.onramp.openWindow({ session, onDepositSettled });

  if (result.status === "blocked") {
    if (result.reason === "popup_blocked") {
      showPopupRetryDialog(result.errorMessage);
    } else {
      kit.onramp.mountIframe({ session, container });
    }
    return;
  }

  result.widget.on("DEPOSIT_NOT_COMPLETED", handleNotCompleted);
});
```

### Popup behavior on mobile

On mobile browsers, `window.open` opens a new tab rather than a sized popup. The
`width` and `height` features are ignored. Design your UX for both outcomes.

### Popup closed before deposit

If the user closes the popup before submitting a deposit, the App Kit SDK
detects it and synthesizes a `DEPOSIT_NOT_COMPLETED` event with code
`CANCELED_BY_CUSTOMER`. Your `onDepositNotCompleted` handler runs without any
extra polling on your side.

## Close the widget

Both `mountIframe` and `openWindow` return a controller with a `close()` method.
Call it when the user leaves the view, closes the modal, or starts over:

```typescript TypeScript theme={null}
let widget: { close: () => void } | undefined;

function mountCurrentSession() {
  widget?.close();
  widget = kit.onramp.mountIframe({ session, container });
}

function stopOnramp() {
  widget?.close();
  widget = undefined;
}
```

For iframe mode, the kit auto-disposes the widget if the container is removed
from the DOM without a `close()` call. Call `widget.close()` when you know the
widget is no longer needed.