Activity Logger Skill

Purpose

Records activities from the current Claude Code session to enable cross-session activity aggregation and work log generation. This skill is designed to work with multiple concurrent Claude Code instances across different projects.

When to Use

Automatic triggers:

• After completing a significant task or feature
• Before switching to a different project
• At the end of a work session

Manual triggers:

• "log this activity"
• "record what I just did"
• "save session activity"
• "log my work"

How It Works

When triggered, this skill will:

1. Collect session information:

   • Generate or retrieve session ID
   • Record current timestamp
   • Identify current project (from git repo or directory name)
   • Get current working directory

2. Gather activity details:

   • Prompt user for activity description (if not provided)
   • List recently modified files (from git status)
   • Capture recent commits (if any)
   • Record task context

3. Save activity record:

   • Create JSON file in ~/.claude/activities/
   • Filename format: {session_id}_{timestamp}.json
   • Ensure directory structure exists

4. Confirm to user:

   • Display saved activity summary
   • Show file path where activity was saved

Activity Record Format

Each activity record is saved as a JSON file with the following structure:

{
  "session_id": "unique-session-identifier",
  "timestamp": "2026-01-13T14:05:30Z",
  "project_path": "/Users/username/projects/my-app",
  "project_name": "my-app",
  "git_branch": "main",
  "activities": [
    {
      "type": "task_completed",
      "description": "Implemented user authentication feature",
      "files_changed": ["src/auth.ts", "src/middleware.ts"],
      "commits": ["a1b2c3d4"]
    }
  ],
  "context": "Working on security improvements",
  "tags": ["authentication", "security"]
}

Activity Types

• task_completed - Finished a specific task or feature
• bug_fixed - Resolved a bug or issue
• refactoring - Code refactoring work
• research - Investigation or exploration work
• documentation - Documentation updates
• review - Code review activities

Usage Examples

Example 1: Simple activity logging

User: "log my work"
Claude: What activity would you like to log?
User: "Implemented OAuth2 login flow"
Claude: [Collects info and saves activity]

Example 2: Automatic logging after task completion

User: "I've finished implementing the dashboard"
Claude: [Completes implementation work]
        Great! Would you like me to log this activity? [logs automatically]

Configuration

Activity logger uses the following directory structure:

~/.claude/
├── activities/           # Activity records
│   ├── session_*.json   # Unprocessed activities
│   └── processed/       # Processed activities (archived)
└── config/
    └── activity-config.json  # Configuration (optional)

Integration with work-log-analyzer

Activity records saved by this skill can be aggregated using the work-log-analyzer skill with the --aggregate flag:

User: "aggregate my activities"
Claude: [Uses work-log-analyzer to process all activity records]

Environment Variables

• CLAUDE_ACTIVITIES_DIR - Override default activities directory (default: ~/.claude/activities)
• CLAUDE_SESSION_ID - Provide custom session ID (auto-generated if not set)

Dependencies

Required

• jq - JSON processor (install: brew install jq on macOS, apt-get install jq on Ubuntu)
• git - Version control system (required for project context)

Optional

• openssl - For secure random ID generation (falls back to /dev/urandom or $RANDOM if not available)

Implementation Notes

The skill implementation:

1. Creates directory structure if it doesn't exist
2. Generates a session ID based on timestamp + random string
3. Uses git commands when available to gather context
4. Falls back to directory scanning if not in a git repo
5. Validates JSON output before saving