Nuxt

In this guide, you'll build a tool-calling AI agent using Mastra, then connect it to Nuxt by importing and calling the agent directly from your server routes.

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

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 Nuxt app (optional)

If you already have a Nuxt app, skip to the next step.

Run the following command to create a new Nuxt app:

npm

npm create nuxt@latest mastra-nuxt -- --template minimal --packageManager npm --gitInit --modules

pnpm

pnpm create nuxt mastra-nuxt --template minimal --packageManager npm --gitInit --modules

Yarn

yarn create nuxt mastra-nuxt --template minimal --packageManager npm --gitInit --modules

Bun

bunx create-nuxt mastra-nuxt --template minimal --packageManager npm --gitInit --modules

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

Initialize Mastra

Navigate to your Nuxt project:

cd mastra-nuxt

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

npm

npx mastra@latest init

pnpm

pnpm dlx mastra@latest init

Yarn

yarn dlx mastra@latest init

Bun

bun x mastra@latest init

This creates a 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 Nuxt server routes in the next steps.

Install AI SDK UI

Install AI SDK UI along with the Mastra adapter:

npm

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

pnpm

pnpm add @mastra/ai-sdk@latest @ai-sdk/vue ai

Yarn

yarn add @mastra/ai-sdk@latest @ai-sdk/vue ai

Bun

bun add @mastra/ai-sdk@latest @ai-sdk/vue ai

Create a chat route

Create server/api/chat.ts:

server/api/chat.ts

import { handleChatStream } from '@mastra/ai-sdk'
import { toAISdkV5Messages } from '@mastra/ai-sdk/ui'
import { createUIMessageStreamResponse } from 'ai'
import { mastra } from '../../src/mastra'

const THREAD_ID = 'example-user-id'
const RESOURCE_ID = 'weather-chat'

export default defineEventHandler(async event => {
  const method = event.method

  if (method === 'POST') {
    const params = await readBody(event)
    const stream = await handleChatStream({
      mastra,
      agentId: 'weather-agent',
      params: {
        ...params,
        memory: {
          ...params.memory,
          thread: THREAD_ID,
          resource: RESOURCE_ID,
        },
      },
    })

    return createUIMessageStreamResponse({ stream })
  }

  if (method === 'GET') {
    const memory = await mastra.getAgentById('weather-agent').getMemory()
    let response = null

    try {
      response = await memory?.recall({
        threadId: THREAD_ID,
        resourceId: RESOURCE_ID,
      })
    } catch {
      console.log('No previous messages found.')
    }

    const uiMessages = toAISdkV5Messages(response?.messages || [])

    return uiMessages
  }
})

The POST handler accepts a prompt and streams the agent's response back in AI SDK format, while the GET handler fetches message history from memory so the UI can be hydrated when the client reloads.

Add the chat UI

Replace the contents of app/app.vue with the following:

app/app.vue

<script setup lang="ts">
  import { ref, onMounted } from 'vue'
  import { Chat } from '@ai-sdk/vue'
  import { DefaultChatTransport, type ToolUIPart } from 'ai'

  const chat = new Chat({
    transport: new DefaultChatTransport({
      api: '/api/chat',
    }),
  })

  const STATE_TO_LABEL_MAP: Record<string, string> = {
    'input-streaming': 'Pending',
    'input-available': 'Running',
    'output-available': 'Completed',
    'output-error': 'Error',
    'output-denied': 'Denied',
  }

  const input = ref('')

  onMounted(async () => {
    const res = await fetch('/api/chat')
    const data = await res.json()
    chat.messages = [...data]
  })

  function handleSubmit() {
    if (!input.value.trim()) return

    chat.sendMessage({ text: input.value })
    input.value = ''
  }
</script>

<template>
  <div class="chat-container">
    <div class="messages">
      <div v-for="message in chat.messages" :key="message.id" class="message-wrapper">
        <div v-for="(part, i) in message.parts" :key="`${message.id}-${i}`">
          <div v-if="part.type === 'text'" :class="['message', message.role]">
            <div class="message-content">{{ part.text }}</div>
          </div>

          <details v-else-if="part.type?.startsWith('tool-')" class="tool">
            <summary class="tool-header">
              {{ (part as ToolUIPart).type?.split('-').slice(1).join('-') }} - {{
              STATE_TO_LABEL_MAP[(part as ToolUIPart).state ?? 'output-available'] }}
            </summary>
            <div class="tool-content">
              <div class="tool-section">
                <div class="tool-label">Parameters</div>
                <pre><code>{{ JSON.stringify((part as ToolUIPart).input, null, 2) }}</code></pre>
              </div>
              <div class="tool-section">
                <div class="tool-label">
                  {{ (part as ToolUIPart).errorText ? 'Error' : 'Result' }}
                </div>
                <pre><code>{{ JSON.stringify((part as ToolUIPart).output, null, 2) }}</code></pre>
                <div v-if="(part as ToolUIPart).errorText" class="tool-error">
                  {{ (part as ToolUIPart).errorText }}
                </div>
              </div>
            </div>
          </details>
        </div>
      </div>
    </div>

    <form class="input-form" @submit.prevent="handleSubmit">
      <input
        v-model="input"
        type="text"
        placeholder="Ask about the weather..."
        :disabled="chat.status !== 'ready'"
        class="chat-input"
      />
      <button type="submit" class="submit-button" :disabled="chat.status !== 'ready'">Send</button>
    </form>
  </div>
</template>

<style>
  *,
  *::before,
  *::after {
    box-sizing: border-box;
  }

  *:not(dialog) {
    margin: 0;
  }

  @media (prefers-reduced-motion: no-preference) {
    html {
      interpolate-size: allow-keywords;
    }
  }

  html {
    font-family:
      -apple-system,
      BlinkMacSystemFont,
      avenir next,
      avenir,
      segoe ui,
      helvetica neue,
      Adwaita Sans,
      Cantarell,
      Ubuntu,
      roboto,
      noto,
      helvetica,
      arial,
      sans-serif;
  }

  body {
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
  }

  img,
  picture,
  video,
  canvas,
  svg {
    display: block;
    max-width: 100%;
  }

  input,
  button,
  textarea,
  select {
    font: inherit;
  }

  p,
  h1,
  h2,
  h3,
  h4,
  h5,
  h6 {
    overflow-wrap: break-word;
  }

  p {
    text-wrap: pretty;
  }
  h1,
  h2,
  h3,
  h4,
  h5,
  h6 {
    text-wrap: balance;
  }

  .chat-container {
    max-width: 48rem;
    margin: 0 auto;
    padding: 1.5rem;
    height: 100vh;
    display: flex;
    flex-direction: column;
  }

  .messages {
    flex: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 1rem;
  }

  .message-wrapper {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
  }

  .message {
    padding: 0.75rem 1rem;
    border-radius: 0.5rem;
  }

  .message.user {
    background-color: #3b82f6;
    color: white;
    margin-left: auto;
    max-width: 60%;
  }

  .message.assistant {
    background-color: #f3f4f6;
    color: #1f2937;
    max-width: 80%;
  }

  .tool {
    border: 1px solid #d1d5db;
    border-radius: 0.5rem;
    margin: 0.5rem 0;
    overflow: hidden;
  }

  .tool-header {
    padding: 0.75rem 1rem;
    background-color: #f9fafb;
    cursor: pointer;
    font-weight: 500;
    font-size: 0.875rem;
  }

  .tool-content {
    padding: 1rem;
    border-top: 1px solid #d1d5db;
  }

  .tool-section {
    margin-bottom: 1rem;
  }

  .tool-section:last-child {
    margin-bottom: 0;
  }

  .tool-label {
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    color: #6b7280;
    margin-bottom: 0.5rem;
  }

  .tool pre {
    background-color: #f3f4f6;
    padding: 0.75rem;
    border-radius: 0.375rem;
    overflow-x: auto;
    font-size: 0.875rem;
  }

  .tool-error {
    color: #dc2626;
    margin-top: 0.5rem;
  }

  .input-form {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 0.75rem;
    padding-top: 1rem;
    border-top: 1px solid #e5e7eb;
    margin-top: 1rem;
  }

  .chat-input {
    padding: 0.75rem 1rem;
    border: 1px solid #d1d5db;
    border-radius: 0.5rem;
    font-size: 1rem;
  }

  .chat-input:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
  }

  .chat-input:disabled {
    background-color: #f3f4f6;
    cursor: not-allowed;
  }

  .submit-button {
    padding: 0.75rem 1.5rem;
    background-color: #3b82f6;
    color: white;
    border: none;
    border-radius: 0.5rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.2s;
  }

  .submit-button:hover:not(:disabled) {
    background-color: #2563eb;
  }

  .submit-button:disabled {
    background-color: #9ca3af;
    cursor: not-allowed;
  }
</style>

This component connects Chat() to the /api/chat endpoint, sending prompts there and streaming the response back in chunks.

It renders the response text using custom message styling and shows any tool invocations in a collapsible details element.

Test your agent

1. Run your Nuxt app with npm run dev
2. Open the chat at http://localhost:3000
3. Try asking about the weather. If your API key is set up correctly, you'll get a response

Next steps

Congratulations on building your Mastra agent with Nuxt! 🎉

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 Nuxt, and how to deploy your agent anywhere:

• Integrate Mastra with AI SDK UI
• Deploy your agent anywhere