> ## Documentation Index
> Fetch the complete documentation index at: https://trigger-maxcomputeseconds.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Streams hooks

> Subscribe to real-time streams from your tasks in React components

These hooks allow you to consume real-time streams from your tasks. Streams are useful for displaying AI/LLM outputs as they're generated, or any other real-time data from your tasks.

<Note>
  To learn how to emit streams from your tasks, see our [Realtime Streams](/tasks/streams)
  documentation.
</Note>

## useRealtimeStream (Recommended)

<Note>
  Available in SDK version **4.1.0 or later**. This is the recommended way to consume streams in
  your React components.
</Note>

The `useRealtimeStream` hook allows you to subscribe to a specific stream by its run ID and stream key. This hook is designed to work seamlessly with [defined streams](/tasks/streams#defining-typed-streams-recommended) for full type safety.

### Basic Usage

```tsx theme={null}
"use client";

import { useRealtimeStream } from "@trigger.dev/react-hooks";

export function StreamViewer({
  runId,
  publicAccessToken,
}: {
  runId: string;
  publicAccessToken: string;
}) {
  const { parts, error } = useRealtimeStream<string>(runId, "ai-output", {
    accessToken: publicAccessToken,
  });

  if (error) return <div>Error: {error.message}</div>;
  if (!parts) return <div>Loading...</div>;

  return (
    <div>
      {parts.map((part, i) => (
        <span key={i}>{part}</span>
      ))}
    </div>
  );
}
```

### With Defined Streams

The recommended approach is to use defined streams for full type safety:

```tsx theme={null}
"use client";

import { useRealtimeStream } from "@trigger.dev/react-hooks";
import { aiStream } from "@/app/streams";

export function StreamViewer({
  runId,
  publicAccessToken,
}: {
  runId: string;
  publicAccessToken: string;
}) {
  // Pass the defined stream directly - full type safety!
  const { parts, error } = useRealtimeStream(aiStream, runId, {
    accessToken: publicAccessToken,
    timeoutInSeconds: 600,
    onData: (chunk) => {
      console.log("New chunk:", chunk); // chunk is typed!
    },
  });

  if (error) return <div>Error: {error.message}</div>;
  if (!parts) return <div>Loading...</div>;

  return (
    <div>
      {parts.map((part, i) => (
        <span key={i}>{part}</span>
      ))}
    </div>
  );
}
```

### Streaming AI Responses

Here's a complete example showing how to display streaming AI responses:

```tsx theme={null}
"use client";

import { useRealtimeStream } from "@trigger.dev/react-hooks";
import { aiStream } from "@/trigger/streams";
import { Streamdown } from "streamdown";

export function AIStreamViewer({
  runId,
  publicAccessToken,
}: {
  runId: string;
  publicAccessToken: string;
}) {
  const { parts, error } = useRealtimeStream(aiStream, runId, {
    accessToken: publicAccessToken,
    timeoutInSeconds: 300,
  });

  if (error) return <div>Error: {error.message}</div>;
  if (!parts) return <div>Loading stream...</div>;

  const text = parts.join("");

  return (
    <div className="prose">
      <Streamdown isAnimating={true}>{text}</Streamdown>
    </div>
  );
}
```

### Options

The `useRealtimeStream` hook accepts the following options:

```tsx theme={null}
const { parts, error } = useRealtimeStream(streamOrRunId, streamKeyOrOptions, {
  accessToken: "pk_...", // Required: Public access token
  baseURL: "https://api.trigger.dev", // Optional: Custom API URL
  timeoutInSeconds: 60, // Optional: Timeout (default: 60)
  startIndex: 0, // Optional: Start from specific chunk
  throttleInMs: 16, // Optional: Throttle updates (default: 16ms)
  onData: (chunk) => {}, // Optional: Callback for each chunk
});
```

### Using Default Stream

You can omit the stream key to use the default stream:

```tsx theme={null}
const { parts, error } = useRealtimeStream<string>(runId, {
  accessToken: publicAccessToken,
});
```

For more information on defining and using streams, see the [Realtime Streams v2](/tasks/streams) documentation.

## useRealtimeRunWithStreams

<Note>
  For new projects, we recommend using `useRealtimeStream` instead (available in SDK 4.1.0+). This
  hook is still supported for backward compatibility and use cases where you need to subscribe to
  both the run and all its streams at once.
</Note>

The `useRealtimeRunWithStreams` hook allows you to subscribe to a run by its ID and also receive any streams that are emitted by the task. This is useful when you need to access both the run metadata and multiple streams simultaneously.

```tsx theme={null}
"use client"; // This is needed for Next.js App Router or other RSC frameworks

import { useRealtimeRunWithStreams } from "@trigger.dev/react-hooks";

export function MyComponent({
  runId,
  publicAccessToken,
}: {
  runId: string;
  publicAccessToken: string;
}) {
  const { run, streams, error } = useRealtimeRunWithStreams(runId, {
    accessToken: publicAccessToken,
  });

  if (error) return <div>Error: {error.message}</div>;

  return (
    <div>
      <div>Run: {run.id}</div>
      <div>
        {Object.keys(streams).map((stream) => (
          <div key={stream}>Stream: {stream}</div>
        ))}
      </div>
    </div>
  );
}
```

You can also provide the type of the streams to the `useRealtimeRunWithStreams` hook to get type-safety:

```tsx theme={null}
import { useRealtimeRunWithStreams } from "@trigger.dev/react-hooks";
import type { myTask } from "@/trigger/myTask";

type STREAMS = {
  openai: string; // this is the type of each "part" of the stream
};

export function MyComponent({
  runId,
  publicAccessToken,
}: {
  runId: string;
  publicAccessToken: string;
}) {
  const { run, streams, error } = useRealtimeRunWithStreams<typeof myTask, STREAMS>(runId, {
    accessToken: publicAccessToken,
  });

  if (error) return <div>Error: {error.message}</div>;

  const text = streams.openai?.map((part) => part).join("");

  return (
    <div>
      <div>Run: {run.id}</div>
      <div>{text}</div>
    </div>
  );
}
```

As you can see above, each stream is an array of the type you provided, keyed by the stream name. If instead of a pure text stream you have a stream of objects, you can provide the type of the object:

```tsx theme={null}
import type { TextStreamPart } from "ai";
import type { myTask } from "@/trigger/myTask";

type STREAMS = { openai: TextStreamPart<{}> };

export function MyComponent({
  runId,
  publicAccessToken,
}: {
  runId: string;
  publicAccessToken: string;
}) {
  const { run, streams, error } = useRealtimeRunWithStreams<typeof myTask, STREAMS>(runId, {
    accessToken: publicAccessToken,
  });

  if (error) return <div>Error: {error.message}</div>;

  const text = streams.openai
    ?.filter((stream) => stream.type === "text-delta")
    ?.map((part) => part.text)
    .join("");

  return (
    <div>
      <div>Run: {run.id}</div>
      <div>{text}</div>
    </div>
  );
}
```

### Streaming AI responses with useRealtimeRunWithStreams

Here's an example showing how to display streaming OpenAI responses using `useRealtimeRunWithStreams`:

```tsx theme={null}
import { useRealtimeRunWithStreams } from "@trigger.dev/react-hooks";
import type { aiStreaming, STREAMS } from "./trigger/ai-streaming";

function MyComponent({ runId, publicAccessToken }: { runId: string; publicAccessToken: string }) {
  const { streams } = useRealtimeRunWithStreams<typeof aiStreaming, STREAMS>(runId, {
    accessToken: publicAccessToken,
  });

  if (!streams.openai) {
    return <div>Loading...</div>;
  }

  const text = streams.openai.join(""); // `streams.openai` is an array of strings

  return (
    <div>
      <h2>OpenAI response:</h2>
      <p>{text}</p>
    </div>
  );
}
```

### AI SDK with tools

When using the AI SDK with tools with `useRealtimeRunWithStreams`, you can access tool calls and results:

```tsx theme={null}
import { useRealtimeRunWithStreams } from "@trigger.dev/react-hooks";
import type { aiStreamingWithTools, STREAMS } from "./trigger/ai-streaming";

function MyComponent({ runId, publicAccessToken }: { runId: string; publicAccessToken: string }) {
  const { streams } = useRealtimeRunWithStreams<typeof aiStreamingWithTools, STREAMS>(runId, {
    accessToken: publicAccessToken,
  });

  if (!streams.openai) {
    return <div>Loading...</div>;
  }

  // streams.openai is an array of TextStreamPart
  const toolCall = streams.openai.find(
    (stream) => stream.type === "tool-call" && stream.toolName === "getWeather"
  );
  const toolResult = streams.openai.find((stream) => stream.type === "tool-result");
  const textDeltas = streams.openai.filter((stream) => stream.type === "text-delta");

  const text = textDeltas.map((delta) => delta.textDelta).join("");
  const weatherLocation = toolCall ? toolCall.args.location : undefined;
  const weather = toolResult ? toolResult.result.temperature : undefined;

  return (
    <div>
      <h2>OpenAI response:</h2>
      <p>{text}</p>
      <h2>Weather:</h2>
      <p>
        {weatherLocation
          ? `The weather in ${weatherLocation} is ${weather} degrees.`
          : "No weather data"}
      </p>
    </div>
  );
}
```

### Throttling updates

The `useRealtimeRunWithStreams` hook accepts an `experimental_throttleInMs` option to throttle the updates from the server. This can be useful if you are getting too many updates and want to reduce the number of updates.

```tsx theme={null}
import { useRealtimeRunWithStreams } from "@trigger.dev/react-hooks";

export function MyComponent({
  runId,
  publicAccessToken,
}: {
  runId: string;
  publicAccessToken: string;
}) {
  const { run, streams, error } = useRealtimeRunWithStreams(runId, {
    accessToken: publicAccessToken,
    experimental_throttleInMs: 1000, // Throttle updates to once per second
  });

  if (error) return <div>Error: {error.message}</div>;

  return (
    <div>
      <div>Run: {run.id}</div>
      {/* Display streams */}
    </div>
  );
}
```

All other options (accessToken, baseURL, enabled, id) work the same as the other realtime hooks.

For the newer `useRealtimeStream` hook, use the `throttleInMs` option instead (see [options above](#options)).