State Management

Effective state management is crucial for building reliable multi-turn agent workflows.

Types of State

Conversation State

Track messages and interaction history:

{
  messages: [
    { role: 'user', content: 'Hello' },
    { role: 'assistant', content: 'Hi there!' }
  ],
  messageCount: 2,
  startTime: Date.now()
}

Agent State

Store agent-specific information:

{
  agentId: 'support-agent-1',
  currentTask: 'resolving-issue',
  tools: ['knowledge-base', 'ticket-system'],
  confidence: 0.95
}

User Context

Maintain user-specific information:

{
  userId: 'user-123',
  preferences: { language: 'en', verbose: true },
  history: [...],
  sessionId: 'session-abc'
}

Application State

Track workflow-level state:

{
  workflowId: 'workflow-xyz',
  status: 'in-progress',
  progress: 65,
  results: {}
}

State Storage Strategies

In-Memory State

Best for single-session interactions:

Fast access
No persistence
Lost on page refresh
Suitable for temporary data

Session Storage

Persist data for current browser session:

sessionStorage.setItem('agentState', JSON.stringify(state));
const state = JSON.parse(sessionStorage.getItem('agentState'));

Local Storage

Persist data across sessions:

localStorage.setItem('userPreferences', JSON.stringify(prefs));
const prefs = JSON.parse(localStorage.getItem('userPreferences'));

Backend Storage

Durable persistence:

Database storage
API synchronization
Cross-device access
Audit trails

State Updates

Immutable Updates

Always create new state objects:

setState(prev => ({
  ...prev,
  messages: [...prev.messages, newMessage]
}));

Batching Updates

Group related changes:

setState({
  currentTask: 'processing',
  progress: 30,
  lastUpdate: Date.now()
});

Async State Management

Handle async operations:

const [state, dispatch] = useReducer(reducer, initialState);

async function updateState() {
  const data = await fetchData();
  dispatch({ type: 'UPDATE', payload: data });
}

Cleanup and Memory Management

Session Cleanup

Clear state on logout or session end:

function cleanupSession() {
  sessionStorage.clear();
  localStorage.removeItem('tempData');
  resetAgentState();
}

Memory Optimization

Limit state size:

Archive old messages
Remove completed tasks
Clear temporary data
Implement data expiration

Debugging State

State Snapshots

Capture state at key points:

console.log('State at checkpoint:', {
  messages: state.messages.length,
  status: state.status,
  timestamp: Date.now()
});

State Validation

Verify state consistency:

function validateState(state) {
  if (!state.messages || !Array.isArray(state.messages)) {
    console.error('Invalid messages array');
  }
  if (state.progress < 0 || state.progress > 100) {
    console.warn('Progress out of range');
  }
}

Next Steps

Learn about data management in MCPs Overview and explore practical examples in Examples & Use Cases.