usage-logging

name	usage-logging
description	Implements structured usage logging and audit trails for cost and session tracking. Use when adding audit trails, usage analytics, or cost tracking to a skill.
alwaysApply	false
category	infrastructure
tags	["logging","usage","audit","metrics","sessions","analytics"]
dependencies	[]
tools	[]
provides	{"infrastructure":["usage-logging","session-management","audit-trails"],"patterns":["structured-logging","metrics-collection","cost-tracking"]}
usage_patterns	["audit-logging","cost-tracking","usage-analytics","session-management"]
complexity	beginner
model_hint	fast
estimated_tokens	450
progressive_loading	true
modules	["modules/session-patterns.md","modules/log-formats.md"]

Table of Contents

• Overview
• When to Use
• Core Concepts
• Session Management
• Log Entry Structure
• Quick Start
• Initialize Logger
• Log Operations
• Query Usage
• Integration Pattern
• Log Storage
• Detailed Resources
• Exit Criteria

Usage Logging

Overview

Records individual call costs and usage events. For aggregate budget enforcement, use quota-management.

Session-aware logging infrastructure for tracking operations across plugins. Provides structured JSONL logging with automatic session management for audit trails and analytics.

When To Use

• Need audit trails for operations
• Tracking costs across sessions
• Building usage analytics
• Debugging with operation history

When NOT To Use

• Simple operations without logging needs

Core Concepts

Session Management

Sessions group related operations:

• Auto-created on first operation
• Timeout after 1 hour of inactivity
• Unique session IDs for tracking

Log Entry Structure

{
  "timestamp": "2025-12-05T10:30:00Z",
  "session_id": "session_1733394600",
  "service": "my-service",
  "operation": "analyze_files",
  "tokens":