Build Your First Full-Stack App

In this tutorial, you’ll build a full-stack task manager with a Go API backend, React frontend, and real-time updates — all served from a single binary.

What We’ll Build

A task manager with:

Go API backend
React frontend with TypeScript
Real-time task updates via SSE
Production build embedded in Go binary

Prerequisites

Go 1.22 or later
Node.js 18 or later
Completed previous tutorials (helpful but not required)

Step 1: Create the Project

# Create project structure
mkdir taskmanager && cd taskmanager
go mod init taskmanager
go get github.com/go-mizu/mizu

# Create frontend with Vite
npm create vite@latest web -- --template react-ts
cd web && npm install && cd ..

Project structure:

taskmanager/
├── main.go           # Go backend
├── go.mod
├── web/              # React frontend
│   ├── src/
│   ├── package.json
│   └── vite.config.ts

Step 2: Create the Backend API

Create main.go:

package main

import (
    "embed"
    "encoding/json"
    "fmt"
    "io/fs"
    "net/http"
    "os"
    "sync"
    "time"

    "github.com/go-mizu/mizu"
)

//go:embed web/dist/*
var frontendFS embed.FS

// Task model
type Task struct {
    ID        string    `json:"id"`
    Title     string    `json:"title"`
    Completed bool      `json:"completed"`
    CreatedAt time.Time `json:"createdAt"`
}

// Storage
var (
    tasks      = make(map[string]*Task)
    tasksMu    sync.RWMutex
    nextID     = 1
    subscribers = make(map[chan *Task]bool)
    subMu      sync.RWMutex
)

// Handlers
func listTasks(c *mizu.Ctx) error {
    tasksMu.RLock()
    defer tasksMu.RUnlock()

    result := make([]*Task, 0, len(tasks))
    for _, t := range tasks {
        result = append(result, t)
    }
    return c.JSON(200, result)
}

func createTask(c *mizu.Ctx) error {
    var input struct {
        Title string `json:"title"`
    }
    if err := c.BindJSON(&input); err != nil || input.Title == "" {
        return c.JSON(400, map[string]string{"error": "title required"})
    }

    tasksMu.Lock()
    id := fmt.Sprintf("%d", nextID)
    nextID++
    task := &Task{
        ID:        id,
        Title:     input.Title,
        CreatedAt: time.Now(),
    }
    tasks[id] = task
    tasksMu.Unlock()

    // Notify subscribers
    broadcast(task)

    return c.JSON(201, task)
}

func toggleTask(c *mizu.Ctx) error {
    id := c.Param("id")

    tasksMu.Lock()
    defer tasksMu.Unlock()

    task, ok := tasks[id]
    if !ok {
        return c.JSON(404, map[string]string{"error": "not found"})
    }

    task.Completed = !task.Completed
    broadcast(task)

    return c.JSON(200, task)
}

func deleteTask(c *mizu.Ctx) error {
    id := c.Param("id")

    tasksMu.Lock()
    defer tasksMu.Unlock()

    if _, ok := tasks[id]; !ok {
        return c.JSON(404, map[string]string{"error": "not found"})
    }

    delete(tasks, id)
    return c.NoContent(204)
}

// SSE for real-time updates
func subscribe(c *mizu.Ctx) error {
    c.Header().Set("Content-Type", "text/event-stream")
    c.Header().Set("Cache-Control", "no-cache")
    c.Header().Set("Connection", "keep-alive")

    ch := make(chan *Task, 10)

    subMu.Lock()
    subscribers[ch] = true
    subMu.Unlock()

    defer func() {
        subMu.Lock()
        delete(subscribers, ch)
        subMu.Unlock()
        close(ch)
    }()

    ctx := c.Context()
    for {
        select {
        case <-ctx.Done():
            return nil
        case task := <-ch:
            data, _ := json.Marshal(task)
            fmt.Fprintf(c.Writer(), "data: %s\n\n", data)
            c.Writer().(http.Flusher).Flush()
        }
    }
}

func broadcast(task *Task) {
    subMu.RLock()
    defer subMu.RUnlock()

    for ch := range subscribers {
        select {
        case ch <- task:
        default:
        }
    }
}

func main() {
    app := mizu.New()

    // API routes
    api := app.Group("/api")
    api.Get("/tasks", listTasks)
    api.Post("/tasks", createTask)
    api.Put("/tasks/{id}/toggle", toggleTask)
    api.Delete("/tasks/{id}", deleteTask)
    api.Get("/events", subscribe)

    // Serve frontend
    if os.Getenv("ENV") == "development" {
        // Proxy to Vite dev server
        fmt.Println("Running in development mode")
        fmt.Println("Start Vite: cd web && npm run dev")
    } else {
        // Serve embedded files
        sub, _ := fs.Sub(frontendFS, "web/dist")
        fileServer := http.FileServer(http.FS(sub))

        app.Get("/{path...}", func(c *mizu.Ctx) error {
            // Try to serve file, fallback to index.html
            path := c.Param("path")
            if path == "" {
                path = "index.html"
            }

            if _, err := fs.Stat(sub, path); err != nil {
                path = "index.html"
            }

            c.Request().URL.Path = "/" + path
            fileServer.ServeHTTP(c.Writer(), c.Request())
            return nil
        })
    }

    fmt.Println("Server running at http://localhost:3000")
    app.Listen(":3000")
}

Step 3: Configure Vite Proxy

Update web/vite.config.ts:

import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'

export default defineConfig({
  plugins: [react()],
  server: {
    port: 5173,
    proxy: {
      '/api': 'http://localhost:3000',
    },
  },
})

Step 4: Create the React Frontend

Replace web/src/App.tsx:

import { useState, useEffect } from 'react'
import './App.css'

interface Task {
  id: string
  title: string
  completed: boolean
  createdAt: string
}

function App() {
  const [tasks, setTasks] = useState<Task[]>([])
  const [newTitle, setNewTitle] = useState('')
  const [loading, setLoading] = useState(true)

  // Fetch initial tasks
  useEffect(() => {
    fetch('/api/tasks')
      .then(res => res.json())
      .then(data => {
        setTasks(data)
        setLoading(false)
      })
  }, [])

  // Subscribe to real-time updates
  useEffect(() => {
    const eventSource = new EventSource('/api/events')

    eventSource.onmessage = (event) => {
      const updatedTask: Task = JSON.parse(event.data)
      setTasks(prev => {
        const index = prev.findIndex(t => t.id === updatedTask.id)
        if (index >= 0) {
          const newTasks = [...prev]
          newTasks[index] = updatedTask
          return newTasks
        }
        return [...prev, updatedTask]
      })
    }

    return () => eventSource.close()
  }, [])

  const addTask = async (e: React.FormEvent) => {
    e.preventDefault()
    if (!newTitle.trim()) return

    const res = await fetch('/api/tasks', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ title: newTitle }),
    })

    if (res.ok) {
      setNewTitle('')
      // Task will be added via SSE
    }
  }

  const toggleTask = async (id: string) => {
    await fetch(`/api/tasks/${id}/toggle`, { method: 'PUT' })
    // Update will come via SSE
  }

  const deleteTask = async (id: string) => {
    await fetch(`/api/tasks/${id}`, { method: 'DELETE' })
    setTasks(prev => prev.filter(t => t.id !== id))
  }

  if (loading) {
    return <div className="loading">Loading...</div>
  }

  return (
    <div className="app">
      <header>
        <h1>Task Manager</h1>
        <p>Built with Mizu + React</p>
      </header>

      <form onSubmit={addTask} className="add-form">
        <input
          type="text"
          value={newTitle}
          onChange={e => setNewTitle(e.target.value)}
          placeholder="What needs to be done?"
        />
        <button type="submit">Add</button>
      </form>

      <ul className="task-list">
        {tasks.map(task => (
          <li key={task.id} className={task.completed ? 'completed' : ''}>
            <label>
              <input
                type="checkbox"
                checked={task.completed}
                onChange={() => toggleTask(task.id)}
              />
              <span>{task.title}</span>
            </label>
            <button onClick={() => deleteTask(task.id)} className="delete">
              ×
            </button>
          </li>
        ))}
      </ul>

      {tasks.length === 0 && (
        <p className="empty">No tasks yet. Add one above!</p>
      )}

      <footer>
        {tasks.filter(t => !t.completed).length} tasks remaining
      </footer>
    </div>
  )
}

export default App

Replace web/src/App.css:

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  padding: 2rem;
}

.app {
  max-width: 500px;
  margin: 0 auto;
  background: white;
  border-radius: 16px;
  padding: 2rem;
  box-shadow: 0 20px 60px rgba(0,0,0,0.3);
}

header {
  text-align: center;
  margin-bottom: 2rem;
}

header h1 {
  color: #333;
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

header p {
  color: #666;
}

.add-form {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.add-form input {
  flex: 1;
  padding: 0.75rem 1rem;
  border: 2px solid #eee;
  border-radius: 8px;
  font-size: 1rem;
  transition: border-color 0.2s;
}

.add-form input:focus {
  outline: none;
  border-color: #667eea;
}

.add-form button {
  padding: 0.75rem 1.5rem;
  background: #667eea;
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.2s;
}

.add-form button:hover {
  background: #5a6fd6;
}

.task-list {
  list-style: none;
}

.task-list li {
  display: flex;
  align-items: center;
  padding: 1rem;
  border-bottom: 1px solid #eee;
  transition: background 0.2s;
}

.task-list li:hover {
  background: #f9f9f9;
}

.task-list li.completed span {
  text-decoration: line-through;
  color: #999;
}

.task-list label {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  cursor: pointer;
}

.task-list input[type="checkbox"] {
  width: 20px;
  height: 20px;
  cursor: pointer;
}

.task-list .delete {
  background: none;
  border: none;
  font-size: 1.5rem;
  color: #ccc;
  cursor: pointer;
  padding: 0 0.5rem;
  transition: color 0.2s;
}

.task-list .delete:hover {
  color: #e74c3c;
}

.empty {
  text-align: center;
  color: #999;
  padding: 2rem;
}

footer {
  text-align: center;
  color: #666;
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid #eee;
}

.loading {
  text-align: center;
  padding: 4rem;
  color: white;
  font-size: 1.5rem;
}

Update web/src/index.css (remove default Vite styles):

:root {
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

Step 5: Development Mode

Run both servers:

# Terminal 1: Start Go backend
go run main.go

# Terminal 2: Start Vite dev server
cd web && npm run dev

Open http://localhost:5173 (Vite will proxy API calls to Go).

Step 6: Production Build

Build everything:

# Build frontend
cd web && npm run build && cd ..

# Build Go binary with embedded frontend
go build -o taskmanager .

Run the production build:

./taskmanager

Open http://localhost:3000 — everything served from one binary!

Step 7: Create a Makefile

Create Makefile:

.PHONY: dev build clean

dev:
	@echo "Starting development servers..."
	@echo "Backend: http://localhost:3000"
	@echo "Frontend: http://localhost:5173"
	@cd web && npm run dev &
	@ENV=development go run main.go

build:
	cd web && npm run build
	go build -o taskmanager .

clean:
	rm -f taskmanager
	rm -rf web/dist

What You Learned

Combining Go backend with React frontend
Development proxy with Vite
Embedding frontend in Go binary
Real-time updates with SSE
Single-binary deployment

Project Structure

taskmanager/
├── main.go
├── go.mod
├── go.sum
├── Makefile
└── web/
    ├── src/
    │   ├── App.tsx
    │   ├── App.css
    │   └── main.tsx
    ├── index.html
    ├── package.json
    ├── tsconfig.json
    └── vite.config.ts

Overview

Getting Started

Core Concepts

Building Your App

Deployment

Learn More

Build Your First Full-Stack App

What We’ll Build

Prerequisites

Step 1: Create the Project

Step 2: Create the Backend API

Step 3: Configure Vite Proxy

Step 4: Create the React Frontend

Step 5: Development Mode

Step 6: Production Build

Step 7: Create a Makefile

What You Learned

Project Structure

Next Steps

Add Authentication

Deploy to Production

Overview

Getting Started

Core Concepts

Building Your App

Deployment

Learn More

​What We’ll Build

​Prerequisites

​Step 1: Create the Project

​Step 2: Create the Backend API

​Step 3: Configure Vite Proxy

​Step 4: Create the React Frontend

​Step 5: Development Mode

​Step 6: Production Build

​Step 7: Create a Makefile

​What You Learned

​Project Structure

​Next Steps

Add Authentication

Deploy to Production

What We’ll Build

Prerequisites

Step 1: Create the Project

Step 2: Create the Backend API

Step 3: Configure Vite Proxy

Step 4: Create the React Frontend

Step 5: Development Mode

Step 6: Production Build

Step 7: Create a Makefile

What You Learned

Project Structure

Next Steps