Claude Code Logger

A specialized HTTP/HTTPS proxy logger designed for analyzing and debugging Claude Code traffic with enhanced chat mode visualization.

🎯 Primary Purpose

This tool was built specifically to help developers understand and debug the communication between Claude Code and the Anthropic API. It provides a clean, formatted view of the conversation flow, making it easier to:

• Debug Claude Code behavior
• Analyze API requests and responses
• Monitor token usage and quotas
• Understand the structure of system prompts and tool usage
• Archive conversations for later analysis

🚀 Quick Start (No Installation Required!)

Simply run these two commands in separate terminals:

Terminal 1 - Start the logger:

npx claude-code-logger start

Terminal 2 - Start Claude Code with proxy:

ANTHROPIC_BASE_URL=http://localhost:8000/ claude

That's it! You'll now see a beautifully formatted log of all Claude Code interactions in your terminal.

For help and options:

npx claude-code-logger start --help

✨ Features

Claude Code Specific

• 🤖 Chat Mode: Automatically enabled by default, shows only the conversation between you and Claude
• 📝 Markdown Rendering: AI responses are rendered with proper formatting (lists, code blocks, emphasis)
• 🔍 System Prompt Visibility: See system reminders, file contents, and context provided to Claude
• 🔧 Tool Usage Tracking: Monitor when Claude uses tools like file reading, editing, or web searches
• 📊 Verbose Mode: Use -v flag to see full prompts without truncation

General Proxy Features

• ✅ HTTP and HTTPS Support: Works with both protocols
• ✅ Request/Response Logging: Detailed logging of all traffic
• ✅ Body Content Logging: Optional logging of request/response bodies
• ✅ Server-Sent Events (SSE): Proper handling and merging of streaming responses
• ✅ Compression Support: Handles gzip, deflate, and brotli compressed responses
• ✅ Parallel Request Handling: Efficiently handles multiple concurrent requests

📋 All CLI Options

claude-code-logger start [options]

Options:
  -p, --port <port>         Local port to listen on (default: 8000)
  -h, --host <host>         Remote host address (default: api.anthropic.com)
  -r, --remote-port <port>  Remote port (default: 443)
  --https                   Use HTTPS for remote connection (default: true)
  --local-https             Accept HTTPS connections locally (default: false)
  --log-body                Log request and response bodies (default: false)
  --merge-sse               Merge Server-Sent Events into readable messages (default: false)
  --debug                   Show debug messages for troubleshooting (default: false)
  --chat-mode               Show only chat conversation with live streaming (default: true)
  -v, --verbose             Show full prompts without truncation (default: false)

🔍 Usage Examples

Claude Code Logging (Primary Use Case)

# Basic usage - logs Claude Code conversations
npm run dev -- start
ANTHROPIC_BASE_URL=http://localhost:8000/ claude

# With full prompt visibility
npm run dev -- start --verbose
ANTHROPIC_BASE_URL=http://localhost:8000/ claude

# With debug information
npm run dev -- start --debug
ANTHROPIC_BASE_URL=http://localhost:8000/ claude

# Log to file for later analysis
npm run dev -- start 2>&1 | tee claude-session-$(date +%Y%m%d-%H%M%S).log

General Proxy Usage

# Proxy any HTTP service
npm run dev -- start -p 3000 -h example.com -r 80 --https=false --chat-mode=false

# Log all traffic with bodies
npm run dev -- start -h api.example.com --log-body --chat-mode=false

# Debug mode for troubleshooting
npm run dev -- start --debug --log-body --chat-mode=false

📸 What You'll See

In chat mode (default), the output is clean and focused:

🚀 Proxy server started on http://localhost:8000
📡 Forwarding to https://api.anthropic.com:443
📝 Logging all traffic to console...

👤 How do I read a file in Python?

🤖 To read a file in Python, you can use the built-in `open()` function. Here are the most common approaches:

### Basic File Reading

```python
# Read entire file content
with open('filename.txt', 'r') as file:
    content = file.read()
    print(content)

... (formatted markdown output) ...

## 🛠 Development

```bash
# Install dependencies
npm install

# Run in development mode
npm run dev -- start

# Build for production
npm run build

# Type checking
npm run typecheck

# Linting
npm run lint

📦 Installation Options

Option 1: Use without installation (Recommended)

npx claude-code-logger start

Option 2: Install globally

npm install -g claude-code-logger
claude-code-logger start

🤝 Contributing

Contributions are welcome! This tool is specifically designed for Claude Code, but can be extended for other use cases.

📄 License

MIT

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Note: This tool is not affiliated with Anthropic. It's an independent project designed to help developers work more effectively with Claude Code.