ai/docs/07-reference/04-stream-helpers/13-cohere-stream.mdx

AI SDK by Vercel - The AI Toolkit for TypeScript and JavaScript

---
title: CohereStream
description: Learn to use CohereStream helper function in your application.
---

# `CohereStream`

<Note type="warning">CohereStream has been removed in AI SDK 4.0.</Note>

<Note type="warning">
  CohereStream is part of the legacy Cohere integration. It is not compatible
  with the AI SDK 3.1 functions.
</Note>

The CohereStream function is a utility that transforms the output from Cohere's API into a ReadableStream. It uses AIStream under the hood, applying a specific parser for the Cohere's response data structure. This works with the official Cohere API, and it's supported in both Node.js, the Edge Runtime, and browser environments.

## Import

### React

<Snippet text={`import { CohereStream } from "ai"`} prompt={false} />

## API Signature

### Parameters

<PropertiesTable
  content={[
    {
      name: 'response',
      type: 'Response',
      description:
        'The response object returned by a call made by the Provider SDK.',
    },
    {
      name: 'callbacks',
      type: 'AIStreamCallbacksAndOptions',
      isOptional: true,
      description:
        '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.',
      properties: [
        {
          type: 'AIStreamCallbacksAndOptions',
          parameters: [
            {
              name: 'onStart',
              type: '() => Promise<void>',
              description:
                'An optional function that is called at the start of the stream processing.',
            },
            {
              name: 'onCompletion',
              type: '(completion: string) => Promise<void>',
              description:
                "An optional function that is called for every completion. It's passed the completion as a string.",
            },
            {
              name: 'onFinal',
              type: '(completion: string) => Promise<void>',
              description:
                'An optional function that is called once when the stream is closed with the final completion message.',
            },
            {
              name: 'onToken',
              type: '(token: string) => Promise<void>',
              description:
                "An optional function that is called for each token in the stream. It's passed the token as a string.",
            },
          ],
        },
      ],
    },
  ]}
/>

### Returns

A `ReadableStream`.