Skip to content


Vercel AI SDK provides a set of utilities to make it easy to use Cohere's API. In this guide, we'll walk through how to use the utilities to create a text completion app.

Guide: Text Completion

Create a Next.js app

Create a Next.js application and install ai:

pnpm dlx create-next-app my-ai-app
cd my-ai-app
pnpm install ai

Add your Cohere API Key to .env


Create a Route Handler

Create a Next.js Route Handler that uses the Edge Runtime to generate a response to a series of messages via Cohere's API, and returns the response as a streaming text response.

For this example, we'll create a route handler at app/api/completion/route.ts that accepts a POST request with a prompt string:

import { StreamingTextResponse, CohereStream } from 'ai';
export async function POST(req: Request) {
  // Extract the `prompt` from the body of the request
  const { prompt } = await req.json();
  const body = JSON.stringify({
    model: 'command-nightly',
    max_tokens: 300,
    stop_sequences: [],
    temperature: 0.9,
    return_likelihoods: 'NONE',
    stream: true,
  const response = await fetch('', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      Authorization: `Bearer ${process.env.COHERE_API_KEY}`,
  // Check for errors
  if (!response.ok) {
    return new Response(await response.text(), {
      status: response.status,
  // Extract the text response from the Cohere stream
  const stream = CohereStream(response);
  // Respond with the stream
  return new StreamingTextResponse(stream);

Wire up the UI

Create a Client component with a form that we'll use to gather the prompt from the user and then stream back the completion from.

By default, the useCompletion hook will use the POST Route Handler we created above (it defaults to /api/completion). You can override this by passing a api prop to useCompletion({ api: '...'}).

'use client';
import { useCompletion } from 'ai/react';
export default function Chat() {
  const { completion, input, handleInputChange, handleSubmit, error } =
  return (
    <div className="flex flex-col w-full max-w-md py-24 mx-auto stretch">
      <h4 className="text-xl font-bold text-gray-900 md:text-xl pb-4">
        useCompletion Example
      {error && (
        <div className="fixed top-0 left-0 w-full p-4 text-center bg-red-500 text-white">
      <form onSubmit={handleSubmit}>
          className="fixed bottom-0 w-full max-w-md p-2 mb-8 border border-gray-300 rounded shadow-xl"
          placeholder="Say something..."

© 2023 Vercel Inc.