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Integrate Mastra in your React + Vite project

In this guide, you'll build a tool-calling AI agent using Mastra, then connect it to React by calling the agent directly from Mastra's standalone server.

You'll use AI SDK UI and AI Elements to create a beautiful, interactive chat experience.

Before you begin
Direct link to Before you begin

  • You'll need an API key from a supported model provider. If you don't have a preference, use OpenAI.
  • Install Node.js v22.13.0 or later

Create a new React + Vite app (optional)
Direct link to Create a new React + Vite app (optional)

If you already have a React + Vite app using Tailwind, skip to the next step.

Project scaffold
Direct link to Project scaffold

Run the following command to create a new React + Vite app:

npm create vite@latest mastra-react -- --template react-ts

This creates a project called mastra-react, but you can replace it with any name you want.

Navigate to your project directory:

cd mastra-react

Tailwind
Direct link to Tailwind

Next, install Tailwind:

npm install tailwindcss @tailwindcss/vite

Configure the Vite plugins:

vite.config.ts
import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'
import path from 'path'
import tailwindcss from '@tailwindcss/vite'

export default defineConfig({
  plugins: [react(), tailwindcss()],
  resolve: {
    alias: {
      '@': path.resolve(__dirname, './src'),
    },
  },
})

Replace everything in src/index.css with the following:

src/index.css
@import 'tailwindcss';

Add these compilerOptions to tsconfig.json:

tsconfig.json
{
  // ...
  "compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "@/*": ["./src/*"],
    },
  },
}

Edit tsconfig.app.json to resolve paths:

tsconfig.app.json
{
  "compilerOptions": {
    // ...
    "baseUrl": ".",
    "paths": {
      "@/*": ["./src/*"],
    },
    // ...
  },
}

Initialize Mastra
Direct link to Initialize Mastra

Run mastra init. When prompted, choose a provider (e.g. OpenAI) and enter your key:

npx mastra@latest init

This creates a src/mastra folder with an example weather agent and the following files:

  • index.ts - Mastra config, including memory
  • tools/weather-tool.ts - a tool to fetch weather for a given location
  • agents/weather-agent.ts- a weather agent with a prompt that uses the tool

You'll call weather-agent.ts from your chat UI in the next steps.

Install AI SDK UI & AI elements
Direct link to Install AI SDK UI & AI elements

Install AI SDK UI along with the Mastra adapter:

npm install @mastra/ai-sdk@latest @ai-sdk/react ai

Next, initialize AI Elements. When prompted, choose the default options:

npx ai-elements@latest

This downloads the entire AI Elements UI component library into a @/components/ai-elements folder.

Create a chat route
Direct link to Create a chat route

Open ⁠src/mastra/index.ts and add a ⁠chatRoute() to your config. This creates an API route your React frontend can call for AI SDK-compatible chat responses, which you’ll use with ⁠useChat() next.

src/mastra/index.ts
import { Mastra } from '@mastra/core/mastra'
// Existing imports...
import { chatRoute } from '@mastra/ai-sdk'

export const mastra = new Mastra({
  // Existing config...
  server: {
    apiRoutes: [
      chatRoute({
        path: '/chat/:agentId',
      }),
    ],
  },
})

Add the chat UI
Direct link to Add the chat UI

Replace the src/App.tsx file to create a chat interface:

src/App.tsx
import * as React from 'react'
import { DefaultChatTransport, type ToolUIPart } from 'ai'
import { useChat } from '@ai-sdk/react'

import {
  PromptInput,
  PromptInputBody,
  PromptInputTextarea,
} from '@/components/ai-elements/prompt-input'

import {
  Conversation,
  ConversationContent,
  ConversationScrollButton,
} from '@/components/ai-elements/conversation'

import { Message, MessageContent, MessageResponse } from '@/components/ai-elements/message'

import { Tool, ToolHeader, ToolContent, ToolInput, ToolOutput } from '@/components/ai-elements/tool'

export default function App() {
  const [input, setInput] = React.useState<string>('')

  const { messages, sendMessage, status } = useChat({
    transport: new DefaultChatTransport({
      api: 'http://localhost:4111/chat/weather-agent',
    }),
  })

  const handleSubmit = async () => {
    if (!input.trim()) return

    sendMessage({ text: input })
    setInput('')
  }

  return (
    <div className="relative mx-auto size-full h-screen max-w-4xl p-6">
      <div className="flex h-full flex-col">
        <Conversation className="h-full">
          <ConversationContent>
            {messages.map(message => (
              <div key={message.id}>
                {message.parts?.map((part, i) => {
                  if (part.type === 'text') {
                    return (
                      <Message key={`${message.id}-${i}`} from={message.role}>
                        <MessageContent>
                          <MessageResponse>{part.text}</MessageResponse>
                        </MessageContent>
                      </Message>
                    )
                  }

                  if (part.type?.startsWith('tool-')) {
                    return (
                      <Tool key={`${message.id}-${i}`}>
                        <ToolHeader
                          type={(part as ToolUIPart).type}
                          state={(part as ToolUIPart).state || 'output-available'}
                          className="cursor-pointer"
                        />
                        <ToolContent>
                          <ToolInput input={(part as ToolUIPart).input || {}} />
                          <ToolOutput
                            output={(part as ToolUIPart).output}
                            errorText={(part as ToolUIPart).errorText}
                          />
                        </ToolContent>
                      </Tool>
                    )
                  }

                  return null
                })}
              </div>
            ))}
            <ConversationScrollButton />
          </ConversationContent>
        </Conversation>
        <PromptInput onSubmit={handleSubmit} className="mt-20">
          <PromptInputBody>
            <PromptInputTextarea
              onChange={e => setInput(e.target.value)}
              className="md:leading-10"
              value={input}
              placeholder="Ask about the weather..."
              disabled={status !== 'ready'}
            />
          </PromptInputBody>
        </PromptInput>
      </div>
    </div>
  )
}

This component connects useChat() to the chat/weather-agent endpoint, sending prompts there and streaming the response back in chunks.

It renders the response text using the <MessageResponse> component, and shows any tool invocations with the <Tool> component.

Test your agent
Direct link to Test your agent

To test your agent with the chat interface, run both the Mastra server and the Vite development server.

  1. Start the Mastra development server:

    npx mastra dev

  2. In a separate terminal window, start the Vite development server:

    npm run dev

  3. Open your application at http://localhost:5173

  4. Try asking about the weather. If your API key is set up correctly, you'll get a response

Next steps
Direct link to Next steps

Congratulations on building your Mastra agent with React! 🎉

From here, you can extend the project with your own tools and logic:

  • Learn more about agents
  • Give your agent its own tools
  • Add human-like memory to your agent

When you're ready, read more about how Mastra integrates with AI SDK UI and React, and how to deploy your agent anywhere:

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