---
title: ReplicateStream
description: Learn to use ReplicateStream helper function in your application.
url: "https://ai-sdk.dev/v5/docs/reference/stream-helpers/replicate-stream"
docs_index: /llms.txt
---

> For an index of all documentation, see [/llms.txt](/llms.txt).

ReplicateStream has been removed in AI SDK 4.0.

ReplicateStream is part of the legacy Replicate integration. It is not
compatible with the AI SDK 3.1 functions.

The ReplicateStream function is a utility that handles extracting the stream from the output of [Replicate](https://replicate.com)'s API. It expects a Prediction object as returned by the [Replicate JavaScript SDK](https://github.com/replicate/replicate-javascript), and returns a ReadableStream. Unlike other wrappers, ReplicateStream returns a Promise because it makes a fetch call to the [Replicate streaming API](https://github.com/replicate/replicate-javascript#streaming) under the hood.

## Import

### React

```
import { ReplicateStream } from "ai"
```

## API Signature

### Parameters

- `pre` (`Prediction`): Object returned by the Replicate JavaScript SDK.
- `callbacks?` (`AIStreamCallbacksAndOptions`): An object containing callback functions to handle the start, each token, and completion of the AI response. In the absence of this parameter, default behavior is implemented.
  - `AIStreamCallbacksAndOptions`
    - `onStart` (`() => Promise<void>`): An optional function that is called at the start of the stream processing.
    - `onCompletion` (`(completion: string) => Promise<void>`): An optional function that is called for every completion. It's passed the completion as a string.
    - `onFinal` (`(completion: string) => Promise<void>`): An optional function that is called once when the stream is closed with the final completion message.
    - `onToken` (`(token: string) => Promise<void>`): An optional function that is called for each token in the stream. It's passed the token as a string.
- `options` (`{ headers?: Record<string, string> }`): An optional parameter for passing additional headers.

### Returns

A `ReadableStream` wrapped in a promise.

---

For a semantic overview of all documentation, see [/sitemap.md](/sitemap.md)

For an index of all available documentation, see [/llms.txt](/llms.txt)

For agent-facing discovery, including API and MCP surfaces, see [/agents.md](/agents.md)