Overview

Implement automatic session storage and a /resume command to allow users to save, list, and restore previous chat sessions.

Goals

• Automatically persist chat sessions to disk
• Allow users to list previous sessions
• Enable resuming any past session with full context
• Handle session cleanup and management

Architecture

Session Storage

Location: ~/.nanocoder-sessions/

File Structure:

~/.nanocoder-sessions/
├── sessions.json          # Index of all sessions
└── {session-id}.json      # Individual session files

Session Schema:

interface Session {
  id: string;              // Unique session ID (timestamp-based)
  title: string;           // Auto-generated from first message or manual
  createdAt: string;       // ISO timestamp
  lastAccessedAt: string;  // ISO timestamp
  messageCount: number;    // Number of messages
  provider: string;        // LLM provider used
  model: string;           // Model used
  workingDirectory: string; // CWD when session created
  messages: Message[];     // Full conversation history
}

Implementation Tasks

1. Session Management Module

File: source/session/session-manager.ts

• createSession() - Initialize new session
• saveSession() - Persist current session to disk
• listSessions() - Get all available sessions
• loadSession() - Load session from disk
• deleteSession() - Remove session file
• autoSave() - Periodic auto-save functionality
• generateSessionTitle() - Create title from first user message

2. Automatic Session Persistence

Integration Point: source/app/hooks/useAppState.ts

• Auto-save after each assistant response
• Debounce to avoid excessive writes
• Save on exit (cleanup handler)
• Update session metadata (lastAccessedAt, messageCount)

3. Session List UI Component

File: source/components/session-selector.tsx

Display format:

Recent Sessions:
[1] Fix authentication bug (15 messages) - 2 hours ago
[2] Add dark mode feature (42 messages) - yesterday
[3] Refactor API client (8 messages) - 3 days ago

Enter number to resume, or 'q' to cancel:

Features:

• Sortable by date/message count
• Search/filter by title or content
• Show provider/model info
• Pagination for large session lists

4. /resume Command Handler

File: source/commands/resume.ts

Behaviors:

• /resume - Show session selector UI
• /resume {id} - Resume specific session by ID
• /resume {number} - Resume by list index
• /resume last - Resume most recent session

5. Command Registration

File: source/commands/index.ts

Add resume command to built-in commands with:

• Help text
• Autocomplete support
• Aliases (/sessions, /history)

6. App State Integration

File: source/app.tsx

• Add resumeSession mode to app state
• Handle session loading on startup
• Restore full conversation context
• Preserve provider/model selection from session

Edge Cases & Considerations

Session Cleanup

• Auto-delete sessions older than X days (configurable)
• Implement session size limits
• Handle disk space issues gracefully

Migration & Compatibility

• Version session schema for future updates
• Handle corrupted session files
• Backward compatibility for older sessions

Context Management

• Validate loaded messages match current tool schema
• Handle sessions from different working directories
• Warn if provider/model no longer available

Performance

• Lazy load session content (index vs full messages)
• Implement session caching
• Optimize for large session lists

Configuration Options

Add to agents.config.json or preferences:

{
  "sessions": {
    "autoSave": true,
    "saveInterval": 5000,
    "maxSessions": 100,
    "retentionDays": 30,
    "directory": "~/.nanocoder-sessions"
  }
}

Testing Considerations

• Test session save/load cycle
• Verify message history integrity
• Test with different providers/models
• Handle concurrent session access
• Test cleanup and migration logic

Implementation Order

1. Create session manager module with core storage logic
2. Implement session schema and file I/O
3. Add automatic session persistence to app state
4. Build session selector UI component
5. Implement /resume command handler
6. Add command registration and integration
7. Implement cleanup and edge case handling
8. Add configuration options
9. Write tests

Future Enhancements

• Session branching (fork conversation at any point)
• Session export/import (share sessions)
• Session search by content
• Session tagging and organization
• Cloud sync for sessions across machines
• Session analytics (token usage, cost tracking)