useMyId

Overview

useMyId returns the unique identifier of the current user when connected to a React Together session. This ID is persistent throughout the session and is essential for implementing user-specific features, personal data management, and identifying the current user in collaborative contexts.

Perfect for: User avatars, personal settings, per-user data, user identification, access control, and distinguishing “self” from other users.

Basic Usage

import { useMyId } from 'react-together'

function UserProfile() {
  const myId = useMyId()
  
  return (
    <div>
      {myId ? (
        <p>Your ID: {myId}</p>
      ) : (
        <p>Not connected to session</p>
      )}
    </div>
  )
}

Signature

useMyId(): string | null

Return Value

myId

string | null

The unique identifier of the current user, or null if not connected to a session

Examples

User Avatar with Self-Identification

Create a user list that highlights the current user:

import { useMyId, useConnectedUsers } from 'react-together'

function UserAvatarList() {
  const myId = useMyId()
  const connectedUsers = useConnectedUsers()
  
  return (
    <div className="user-avatar-list">
      <h3>Connected Users</h3>
      <div className="avatar-grid">
        {connectedUsers.map(user => (
          <div
            key={user.userId}
            className={`user-avatar ${user.userId === myId ? 'me' : 'other'}`}
          >
            <div className="avatar-image">
              {user.nickname.charAt(0).toUpperCase()}
            </div>
            <div className="user-info">
              <span className="username">
                {user.nickname}
                {user.userId === myId && ' (You)'}
              </span>
              <span className="user-id">
                ID: {user.userId.slice(0, 8)}...
              </span>
            </div>
            {user.userId === myId && (
              <div className="self-indicator">
                👤 You
              </div>
            )}
          </div>
        ))}
      </div>
    </div>
  )
}

Personal Settings Management

Store and manage per-user settings:

import { useMyId, useStateTogetherWithPerUserValues } from 'react-together'
import { useState, useEffect } from 'react'

interface UserSettings {
  theme: 'light' | 'dark'
  notifications: boolean
  language: string
  volume: number
}

function PersonalSettings() {
  const myId = useMyId()
  const [settings, setSettings, allSettings] = useStateTogetherWithPerUserValues<UserSettings>(
    'user-settings',
    {
      theme: 'light',
      notifications: true,
      language: 'en',
      volume: 0.8
    }
  )
  
  // Apply user's theme to the app
  useEffect(() => {
    if (myId && settings) {
      document.body.className = `theme-${settings.theme}`
    }
  }, [settings?.theme, myId])
  
  const updateSetting = <K extends keyof UserSettings>(
    key: K,
    value: UserSettings[K]
  ) => {
    setSettings({ ...settings, [key]: value })
  }
  
  if (!myId) {
    return (
      <div className="settings-panel">
        <p>Connect to a session to access personal settings</p>
      </div>
    )
  }
  
  return (
    <div className="settings-panel">
      <div className="settings-header">
        <h2>Personal Settings</h2>
        <div className="user-info">
          <span className="user-id">User ID: {myId.slice(0, 8)}...</span>
        </div>
      </div>
      
      <div className="settings-form">
        <div className="setting-group">
          <label htmlFor="theme">Theme</label>
          <select
            id="theme"
            value={settings.theme}
            onChange={(e) => updateSetting('theme', e.target.value as 'light' | 'dark')}
          >
            <option value="light">Light</option>
            <option value="dark">Dark</option>
          </select>
        </div>
        
        <div className="setting-group">
          <label htmlFor="notifications">
            <input
              id="notifications"
              type="checkbox"
              checked={settings.notifications}
              onChange={(e) => updateSetting('notifications', e.target.checked)}
            />
            Enable Notifications
          </label>
        </div>
        
        <div className="setting-group">
          <label htmlFor="language">Language</label>
          <select
            id="language"
            value={settings.language}
            onChange={(e) => updateSetting('language', e.target.value)}
          >
            <option value="en">English</option>
            <option value="es">Español</option>
            <option value="fr">Français</option>
            <option value="de">Deutsch</option>
          </select>
        </div>
        
        <div className="setting-group">
          <label htmlFor="volume">Volume: {Math.round(settings.volume * 100)}%</label>
          <input
            id="volume"
            type="range"
            min="0"
            max="1"
            step="0.1"
            value={settings.volume}
            onChange={(e) => updateSetting('volume', parseFloat(e.target.value))}
          />
        </div>
      </div>
      
      <div className="settings-info">
        <p>
          Your settings are synced across all your devices in this session.
        </p>
        <p>
          Other users: {Object.keys(allSettings).length - 1} have their own settings.
        </p>
      </div>
    </div>
  )
}

User-Specific Workspace

Create personalized workspaces for each user:

import { useMyId, useStateTogetherWithPerUserValues } from 'react-together'

interface UserWorkspace {
  notes: string
  bookmarks: Array<{ id: string; title: string; url: string }>
  tasks: Array<{ id: string; text: string; completed: boolean }>
}

function PersonalWorkspace() {
  const myId = useMyId()
  const [workspace, setWorkspace] = useStateTogetherWithPerUserValues<UserWorkspace>(
    'personal-workspace',
    {
      notes: '',
      bookmarks: [],
      tasks: []
    }
  )
  
  const addBookmark = (title: string, url: string) => {
    const newBookmark = {
      id: Date.now().toString(),
      title,
      url
    }
    setWorkspace({
      ...workspace,
      bookmarks: [...workspace.bookmarks, newBookmark]
    })
  }
  
  const addTask = (text: string) => {
    const newTask = {
      id: Date.now().toString(),
      text,
      completed: false
    }
    setWorkspace({
      ...workspace,
      tasks: [...workspace.tasks, newTask]
    })
  }
  
  const toggleTask = (taskId: string) => {
    setWorkspace({
      ...workspace,
      tasks: workspace.tasks.map(task =>
        task.id === taskId ? { ...task, completed: !task.completed } : task
      )
    })
  }
  
  if (!myId) {
    return (
      <div className="workspace">
        <div className="connect-prompt">
          <h2>Personal Workspace</h2>
          <p>Connect to a session to access your personal workspace</p>
        </div>
      </div>
    )
  }
  
  return (
    <div className="personal-workspace">
      <div className="workspace-header">
        <h2>My Workspace</h2>
        <div className="user-badge">
          <span className="user-icon">👤</span>
          <span className="user-id">{myId.slice(0, 8)}...</span>
        </div>
      </div>
      
      <div className="workspace-grid">
        {/* Personal Notes */}
        <div className="workspace-section">
          <h3>📝 My Notes</h3>
          <textarea
            value={workspace.notes}
            onChange={(e) => setWorkspace({ ...workspace, notes: e.target.value })}
            placeholder="Write your personal notes here..."
            rows={8}
          />
        </div>
        
        {/* Personal Bookmarks */}
        <div className="workspace-section">
          <h3>🔖 My Bookmarks</h3>
          <div className="bookmark-input">
            <input
              type="text"
              placeholder="Bookmark title"
              onKeyPress={(e) => {
                if (e.key === 'Enter') {
                  const title = e.currentTarget.value
                  const url = prompt('Enter URL:')
                  if (title && url) {
                    addBookmark(title, url)
                    e.currentTarget.value = ''
                  }
                }
              }}
            />
          </div>
          <div className="bookmark-list">
            {workspace.bookmarks.map(bookmark => (
              <div key={bookmark.id} className="bookmark-item">
                <a href={bookmark.url} target="_blank" rel="noopener noreferrer">
                  {bookmark.title}
                </a>
              </div>
            ))}
          </div>
        </div>
        
        {/* Personal Tasks */}
        <div className="workspace-section">
          <h3>✅ My Tasks</h3>
          <div className="task-input">
            <input
              type="text"
              placeholder="Add a personal task..."
              onKeyPress={(e) => {
                if (e.key === 'Enter' && e.currentTarget.value.trim()) {
                  addTask(e.currentTarget.value.trim())
                  e.currentTarget.value = ''
                }
              }}
            />
          </div>
          <div className="task-list">
            {workspace.tasks.map(task => (
              <div
                key={task.id}
                className={`task-item ${task.completed ? 'completed' : ''}`}
              >
                <input
                  type="checkbox"
                  checked={task.completed}
                  onChange={() => toggleTask(task.id)}
                />
                <span className="task-text">{task.text}</span>
              </div>
            ))}
          </div>
        </div>
      </div>
      
      <div className="workspace-footer">
        <p>
          This workspace is private to user <code>{myId}</code> 
          and syncs across all your devices in this session.
        </p>
      </div>
    </div>
  )
}

Chat System with User Identification

Build a chat system that identifies the current user:

import { useMyId, useChat, useConnectedUsers } from 'react-together'
import { useState } from 'react'

function PersonalizedChat() {
  const myId = useMyId()
  const { messages, sendMessage } = useChat()
  const connectedUsers = useConnectedUsers()
  const [messageText, setMessageText] = useState('')
  
  const handleSendMessage = () => {
    if (messageText.trim() && myId) {
      sendMessage(messageText.trim())
      setMessageText('')
    }
  }
  
  const getUserNickname = (userId: string) => {
    const user = connectedUsers.find(u => u.userId === userId)
    return user?.nickname || `User ${userId.slice(0, 8)}`
  }
  
  if (!myId) {
    return (
      <div className="chat-container">
        <div className="chat-disabled">
          <p>Connect to a session to join the chat</p>
        </div>
      </div>
    )
  }
  
  return (
    <div className="personalized-chat">
      <div className="chat-header">
        <h3>Team Chat</h3>
        <div className="current-user">
          <span className="user-indicator">You: {getUserNickname(myId)}</span>
          <span className="user-id">({myId.slice(0, 8)}...)</span>
        </div>
      </div>
      
      <div className="chat-messages">
        {messages.map((message, index) => {
          const isMyMessage = message.senderId === myId
          
          return (
            <div
              key={index}
              className={`message ${isMyMessage ? 'my-message' : 'other-message'}`}
            >
              <div className="message-header">
                <span className="sender-name">
                  {isMyMessage ? 'You' : getUserNickname(message.senderId)}
                </span>
                <span className="message-time">
                  {new Date(message.timestamp).toLocaleTimeString()}
                </span>
              </div>
              <div className="message-content">
                {message.text}
              </div>
              {isMyMessage && (
                <div className="message-indicator">
                  <span className="my-message-badge">Your message</span>
                </div>
              )}
            </div>
          )
        })}
      </div>
      
      <div className="chat-input">
        <div className="input-container">
          <input
            type="text"
            value={messageText}
            onChange={(e) => setMessageText(e.target.value)}
            onKeyPress={(e) => {
              if (e.key === 'Enter') {
                handleSendMessage()
              }
            }}
            placeholder={`Message as ${getUserNickname(myId)}...`}
          />
          <button
            onClick={handleSendMessage}
            disabled={!messageText.trim()}
          >
            Send
          </button>
        </div>
        <div className="typing-indicator">
          Sending as: <strong>{getUserNickname(myId)}</strong> ({myId.slice(0, 8)}...)
        </div>
      </div>
    </div>
  )
}

Access Control and Permissions

Implement user-based access control:

import { useMyId, useStateTogether } from 'react-together'
import { useState, useEffect } from 'react'

interface UserPermissions {
  [userId: string]: {
    role: 'admin' | 'editor' | 'viewer'
    permissions: string[]
  }
}

function AccessControlledEditor() {
  const myId = useMyId()
  const [content, setContent] = useStateTogether('shared-document', '')
  const [permissions, setPermissions] = useStateTogether<UserPermissions>('user-permissions', {})
  const [isAdmin, setIsAdmin] = useState(false)
  
  // Initialize permissions for new users
  useEffect(() => {
    if (myId && !permissions[myId]) {
      // First user becomes admin, others become editors
      const isFirstUser = Object.keys(permissions).length === 0
      const newPermissions = {
        ...permissions,
        [myId]: {
          role: isFirstUser ? 'admin' : 'editor',
          permissions: isFirstUser 
            ? ['read', 'write', 'admin', 'manage-users']
            : ['read', 'write']
        }
      }
      setPermissions(newPermissions)
    }
  }, [myId, permissions, setPermissions])
  
  // Update admin status
  useEffect(() => {
    if (myId && permissions[myId]) {
      setIsAdmin(permissions[myId].role === 'admin')
    }
  }, [myId, permissions])
  
  const canEdit = myId && permissions[myId]?.permissions.includes('write')
  const canManageUsers = myId && permissions[myId]?.permissions.includes('manage-users')
  
  const updateUserRole = (userId: string, role: 'admin' | 'editor' | 'viewer') => {
    if (!canManageUsers) return
    
    const rolePermissions = {
      admin: ['read', 'write', 'admin', 'manage-users'],
      editor: ['read', 'write'],
      viewer: ['read']
    }
    
    setPermissions({
      ...permissions,
      [userId]: {
        role,
        permissions: rolePermissions[role]
      }
    })
  }
  
  if (!myId) {
    return (
      <div className="access-controlled-editor">
        <div className="access-denied">
          <h2>Access Denied</h2>
          <p>You must be connected to a session to access this document</p>
        </div>
      </div>
    )
  }
  
  const userRole = permissions[myId]?.role || 'viewer'
  
  return (
    <div className="access-controlled-editor">
      <div className="editor-header">
        <div className="document-info">
          <h2>Shared Document</h2>
          <div className="user-status">
            <span className="current-user">
              You: {myId.slice(0, 8)}...
            </span>
            <span className={`role-badge ${userRole}`}>
              {userRole.toUpperCase()}
            </span>
          </div>
        </div>
        
        {canManageUsers && (
          <div className="admin-controls">
            <h4>User Management</h4>
            <div className="user-permissions">
              {Object.entries(permissions).map(([userId, userPerm]) => (
                <div key={userId} className="user-permission-item">
                  <span className="user-id">
                    {userId.slice(0, 8)}... {userId === myId && '(You)'}
                  </span>
                  <select
                    value={userPerm.role}
                    onChange={(e) => updateUserRole(userId, e.target.value as any)}
                    disabled={userId === myId} // Can't change own role
                  >
                    <option value="admin">Admin</option>
                    <option value="editor">Editor</option>
                    <option value="viewer">Viewer</option>
                  </select>
                </div>
              ))}
            </div>
          </div>
        )}
      </div>
      
      <div className="editor-body">
        <textarea
          value={content}
          onChange={(e) => canEdit ? setContent(e.target.value) : undefined}
          disabled={!canEdit}
          className={`document-editor ${!canEdit ? 'read-only' : ''}`}
          placeholder={
            canEdit
              ? "Start typing..."
              : "You have read-only access to this document"
          }
          rows={15}
        />
        
        {!canEdit && (
          <div className="read-only-notice">
            <p>
              You have {userRole} access. Contact an admin for edit permissions.
            </p>
          </div>
        )}
      </div>
      
      <div className="editor-footer">
        <div className="permissions-info">
          <h4>Your Permissions:</h4>
          <ul>
            {permissions[myId]?.permissions.map(perm => (
              <li key={perm} className="permission-item">
                ✓ {perm.replace('-', ' ').toUpperCase()}
              </li>
            ))}
          </ul>
        </div>
      </div>
    </div>
  )
}

User Progress Tracking

Track individual user progress in a collaborative app:

import { useMyId, useStateTogetherWithPerUserValues } from 'react-together'
import { useState, useEffect } from 'react'

interface UserProgress {
  level: number
  score: number
  completedTasks: string[]
  lastActive: string
  achievements: string[]
}

function UserProgressTracker() {
  const myId = useMyId()
  const [progress, setProgress, allProgress] = useStateTogetherWithPerUserValues<UserProgress>(
    'user-progress',
    {
      level: 1,
      score: 0,
      completedTasks: [],
      lastActive: new Date().toISOString(),
      achievements: []
    }
  )
  
  // Update last active time
  useEffect(() => {
    if (myId) {
      const interval = setInterval(() => {
        setProgress({
          ...progress,
          lastActive: new Date().toISOString()
        })
      }, 60000) // Update every minute
      
      return () => clearInterval(interval)
    }
  }, [myId, progress, setProgress])
  
  const completeTask = (taskId: string, points: number) => {
    if (!progress.completedTasks.includes(taskId)) {
      const newScore = progress.score + points
      const newLevel = Math.floor(newScore / 1000) + 1
      const newAchievements = [...progress.achievements]
      
      // Check for achievements
      if (newLevel > progress.level) {
        newAchievements.push(`Level ${newLevel} Reached`)
      }
      if (newScore >= 5000 && !newAchievements.includes('High Scorer')) {
        newAchievements.push('High Scorer')
      }
      
      setProgress({
        ...progress,
        score: newScore,
        level: newLevel,
        completedTasks: [...progress.completedTasks, taskId],
        achievements: newAchievements,
        lastActive: new Date().toISOString()
      })
    }
  }
  
  const getLeaderboard = () => {
    return Object.entries(allProgress)
      .map(([userId, userProgress]) => ({
        userId,
        ...userProgress,
        isMe: userId === myId
      }))
      .sort((a, b) => b.score - a.score)
  }
  
  if (!myId) {
    return (
      <div className="progress-tracker">
        <p>Connect to a session to track your progress</p>
      </div>
    )
  }
  
  const leaderboard = getLeaderboard()
  const myRank = leaderboard.findIndex(user => user.userId === myId) + 1
  
  return (
    <div className="user-progress-tracker">
      <div className="my-progress">
        <h2>My Progress</h2>
        <div className="progress-card">
          <div className="user-info">
            <span className="user-id">ID: {myId.slice(0, 8)}...</span>
            <span className="rank">Rank: #{myRank}</span>
          </div>
          
          <div className="stats-grid">
            <div className="stat">
              <span className="stat-label">Level</span>
              <span className="stat-value">{progress.level}</span>
            </div>
            <div className="stat">
              <span className="stat-label">Score</span>
              <span className="stat-value">{progress.score.toLocaleString()}</span>
            </div>
            <div className="stat">
              <span className="stat-label">Tasks</span>
              <span className="stat-value">{progress.completedTasks.length}</span>
            </div>
          </div>
          
          <div className="level-progress">
            <div className="progress-bar">
              <div
                className="progress-fill"
                style={{
                  width: `${((progress.score % 1000) / 1000) * 100}%`
                }}
              />
            </div>
            <span className="progress-text">
              {progress.score % 1000}/1000 to Level {progress.level + 1}
            </span>
          </div>
          
          {progress.achievements.length > 0 && (
            <div className="achievements">
              <h4>Achievements</h4>
              <div className="achievement-list">
                {progress.achievements.map((achievement, index) => (
                  <span key={index} className="achievement-badge">
                    🏆 {achievement}
                  </span>
                ))}
              </div>
            </div>
          )}
        </div>
        
        <div className="task-actions">
          <h3>Complete Tasks</h3>
          <div className="task-buttons">
            <button onClick={() => completeTask('easy-task', 100)}>
              Easy Task (+100 pts)
            </button>
            <button onClick={() => completeTask('medium-task', 250)}>
              Medium Task (+250 pts)
            </button>
            <button onClick={() => completeTask('hard-task', 500)}>
              Hard Task (+500 pts)
            </button>
          </div>
        </div>
      </div>
      
      <div className="leaderboard">
        <h3>Leaderboard</h3>
        <div className="leaderboard-list">
          {leaderboard.map((user, index) => (
            <div
              key={user.userId}
              className={`leaderboard-item ${user.isMe ? 'my-entry' : ''}`}
            >
              <span className="rank">#{index + 1}</span>
              <span className="user">
                {user.userId.slice(0, 8)}... {user.isMe && '(You)'}
              </span>
              <span className="level">Lv.{user.level}</span>
              <span className="score">{user.score.toLocaleString()}</span>
            </div>
          ))}
        </div>
      </div>
    </div>
  )
}

Best Practices

Safe ID Usage

Always check for null before using the ID:

import { useMyId } from 'react-together'

function SafeIdUsage() {
  const myId = useMyId()
  
  // Always check for null
  if (!myId) {
    return <div>Not connected to session</div>
  }
  
  // Safe to use myId here
  return <div>Your ID: {myId}</div>
}

ID-Based State Management

Use the ID for user-specific state keys:

import { useMyId, useStateTogether } from 'react-together'

function UserSpecificState() {
  const myId = useMyId()
  
  // Create user-specific state key
  const stateKey = myId ? `user-data-${myId}` : null
  const [userData, setUserData] = useStateTogether(stateKey || 'default', {})
  
  return (
    <div>
      {myId ? (
        <div>User data for {myId}: {JSON.stringify(userData)}</div>
      ) : (
        <div>No user ID available</div>
      )}
    </div>
  )
}

Common Patterns

User Identification: Distinguish the current user from others
Personal Data: Store user-specific information and settings
Access Control: Implement user-based permissions and roles
Progress Tracking: Track individual user progress and achievements
UI Personalization: Customize interface based on user identity

useConnectedUsers - Get all users including yourself
useStateTogetherWithPerUserValues - Store per-user data
useNicknames - User display names
useIsTogether - Check connection status

TypeScript Support

useMyId is fully typed and returns a string or null:

import { useMyId } from 'react-together'

const myId: string | null = useMyId()

// Type guard for safe usage
if (myId) {
  const userId: string = myId // Now guaranteed to be string
}

Technical Notes

useMyId is an alias for useViewId from @multisynq/react. The ID is stable throughout a session but may change between different sessions.

Always check for null before using the ID. The hook returns null when not connected to a session, which can cause runtime errors if not handled properly.

Getting Started

Core Hooks

Connection & Session Hooks

Communication Hooks

Utility Hooks

Components

Utilities

Overview

Basic Usage

Signature

Return Value

Examples

User Avatar with Self-Identification

Personal Settings Management

User-Specific Workspace

Chat System with User Identification

Access Control and Permissions

User Progress Tracking

Best Practices

Safe ID Usage

ID-Based State Management

Common Patterns

TypeScript Support

Technical Notes

Getting Started

Core Hooks

Connection & Session Hooks

Communication Hooks

Utility Hooks

Components

Utilities

​Overview

​Basic Usage

​Signature

​Return Value

​Examples

​User Avatar with Self-Identification

​Personal Settings Management

​User-Specific Workspace

​Chat System with User Identification

​Access Control and Permissions

​User Progress Tracking

​Best Practices

​Safe ID Usage

​ID-Based State Management

​Common Patterns

​Related Hooks

​TypeScript Support

​Technical Notes

Overview

Basic Usage

Signature

Return Value

Examples

User Avatar with Self-Identification

Personal Settings Management

User-Specific Workspace

Chat System with User Identification

Access Control and Permissions

User Progress Tracking

Best Practices

Safe ID Usage

ID-Based State Management

Common Patterns

Related Hooks

TypeScript Support

Technical Notes