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:
``bash
npx claude-code-logger start
`

Terminal 2 - Start Claude Code with proxy:
`bash
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:
`bash
npx claude-code-logger start --help
`

✨ Features

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- 🤖 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

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- ✅ 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

`bash
claude-code-logger start [options]

Options:
-p, --port Local port to listen on (default: 8000)
-h, --host Remote host address (default: api.anthropic.com)
-r, --remote-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

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`bash

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
`

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`bash

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:

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`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

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`bash
npx claude-code-logger start
`

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`bash
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.