cc-inspector

A transparent proxy for the Anthropic Claude API that captures every request and response, letting you inspect system prompts, tool definitions, messages, and token usage in a web UI.

Built for understanding what Claude Code sends to the API under the hood.

Quick Start

bunx cc-inspector

Then launch Claude Code through the proxy:

ANTHROPIC_BASE_URL=http://localhost:25947/proxy claude

Open http://localhost:25947 to see captured requests in real time.

What You Can See

• System prompts — the full system message Claude Code sends, including CLAUDE.md contents and tool instructions
• Tool definitions — every tool available to the model, with names, descriptions, and input schemas
• Messages — the complete conversation history sent in each request, with renderers for text, thinking, tool_use, and tool_result blocks
• Token usage — input/output token counts per request
• Streaming — captures SSE streaming responses without buffering
• Filtering — filter by session ID or model

Options

--port, -p <number>  Port to listen on (default: 25947, env: PORT)

You can also set the port via the PORT environment variable:

PORT=3000 bunx cc-inspector

Or pass it as a flag:

bunx cc-inspector --port 3000

How It Works

The proxy sits between Claude Code and api.anthropic.com. Setting ANTHROPIC_BASE_URL tells Claude Code to send API requests to the proxy instead of directly to Anthropic. The proxy forwards everything to the real API and logs both the request and response.

Claude Code  →  cc-inspector (:25947/proxy/*)  →  api.anthropic.com
                      ↓
                Web UI (:25947)

Logs are stored in memory only and reset when the server restarts.