AI SDK RSCError Handling

Error Handling

Two categories of errors can occur when working with the RSC API: errors while streaming user interfaces and errors while streaming other values.

Handling UI Errors

To handle errors while generating UI, the streamableUI object exposes an error() method.

app/actions.tsx

'use server';

import { createStreamableUI } from 'ai/rsc';

export async function getStreamedUI() {
  const ui = createStreamableUI();

  (async () => {
    ui.update(<div>loading</div>);
    const data = await fetchData();
    ui.done(<div>{data}</div>);
  })().catch(e => {
    ui.error(<div>Error: {e.message}</div>);
  });

  return ui.value;
}

With this method, you can catch any error with the stream, and return relevant UI. On the client, you can also use a React Error Boundary to wrap the streamed component and catch any additional errors.

app/page.tsx

import { getStreamedUI } from '@/actions';
import { useState } from 'react';
import { ErrorBoundary } from './ErrorBoundary';

export default function Page() {
  const [streamedUI, setStreamedUI] = useState(null);

  return (
    <div>
      <button
        onClick={async () => {
          const newUI = await getStreamedUI();
          setStreamedUI(newUI);
        }}
      >
        What does the new UI look like?
      </button>
      <ErrorBoundary>{streamedUI}</ErrorBoundary>
    </div>
  );
}

Handling Other Errors

To handle other errors while streaming, you can return an error object that the reciever can use to determine why the failure occurred.

app/actions.tsx

'use server';

import { createStreamableValue } from 'ai/rsc';
import { fetchData, emptyData } from '../utils/data';

export const getStreamedData = async () => {
  const streamableData = createStreamableValue<string>(emptyData);

  try {
    (() => {
      const data1 = await fetchData();
      streamableData.update(data1);

      const data2 = await fetchData();
      streamableData.update(data2);

      const data3 = await fetchData();
      streamableData.done(data3);
    })();

    return { data: streamableData.value };
  } catch (e) {
    return { error: e.message };
  }
};