Watchtower

Monitor, inspect, and debug all API traffic between AI coding agents and their APIs — with a real-time web dashboard.

Like Chrome DevTools Network tab, but for Claude Code and Codex CLI.

Why

AI coding agents make dozens of API calls per interaction — streaming messages, token counts, quota checks, subagent spawns — and you can't see any of it. Watchtower sits between your AI agent and its API, captures everything, and gives you a live dashboard to inspect it all.

Works with:

• Claude Code (Anthropic)
• Codex CLI (OpenAI)
• Any OpenAI-compatible client

What you see:

• Every request and response, fully decoded
• SSE stream events in real time
• Agent hierarchy tracking (main agent → subagents → utility calls)
• Token usage, rate limits, and timing
• System prompts, tool definitions, full message history
• Dark and light mode
• All logged to disk as JSON for later analysis

Quick Start

npm install -g watchtower-ai
watchtower-ai

Or clone and run directly:

git clone https://github.com/fahd09/watchtower.git
cd watchtower
npm install
npm start

Then point your AI agent at the proxy:

# Claude Code
ANTHROPIC_BASE_URL=http://localhost:8024 claude

# Codex CLI
OPENAI_BASE_URL=http://localhost:8024 codex

Open http://localhost:8025 — that's it. Both providers share the same proxy port. Requests are auto-detected.

Usage

# Default ports: proxy=8024, dashboard=8025
node intercept.mjs

# Custom ports
node intercept.mjs 9000 9001

Dashboard Tabs

Tab	What it shows
Overview	Duration, model, status, token counts, rate limits
Messages	Full conversation history (user/assistant messages)
Response	Pretty-printed response JSON
Tools	Tool definitions with searchable parameters and schemas
Stream	Raw SSE events with expandable payloads
Headers	Request and response headers
Rate Limits	Rate limit headers with visual progress bars
Raw	Complete request/response bodies as JSON

Request Classification

The proxy automatically classifies each request:

Anthropic:

• messages_stream — Streaming chat (the main interaction)
• messages — Non-streaming chat
• token_count — Token counting
• quota_check — Quota/permission check (max_tokens=1)

OpenAI:

• responses_stream / responses — Responses API (Codex CLI default)
• chat_stream / chat_completion — Chat Completions API
• models — Model listing
• embeddings — Embedding requests

Agent Roles

Each request is tagged with an agent role:

• main — The primary agent (Claude Code's main agent has the Agent tool; Codex requests with tools)
• subagent — A spawned sub-agent (Explore, Plan, etc.)
• utility — Token counts, quota checks, and tool-less calls

Logs

All requests are saved to ./logs/ as numbered JSON files:

logs/0001_messages_stream_claude-opus-4-6.json
logs/0002_token_count_claude-haiku-4-5-20251001.json

Each file contains the complete request/response cycle: headers, body, SSE events, timing, and rate limits.

How It Works

Claude Code  ──HTTP──┐
                     ├──>  Watchtower (proxy)  ──HTTPS──>  api.anthropic.com
Codex CLI    ──HTTP──┘          │              ──HTTPS──>  api.openai.com / chatgpt.com
                                │
                                ├── logs to disk
                                ├── broadcasts via WebSocket
                                │
                          Dashboard (web UI)

1. Your AI agent sends requests to the local proxy instead of directly to the API
2. Watchtower auto-detects the provider and forwards to the correct upstream
3. Responses (including SSE streams) are decoded, logged, and forwarded back
4. The dashboard connects via WebSocket for real-time updates

Requirements

• Node.js >= 18

Roadmap

See TODO.md for the full roadmap, including planned features like:

• Cost & token tracking
• Search & filter
• System prompt diffing
• Request replay & modification (Burp Suite for Claude)
• Agent hierarchy tree visualization

Contributing

Contributions welcome. Open an issue first for anything non-trivial.

git clone https://github.com/fahd09/watchtower.git
cd watchtower
npm install
npm start

The proxy is in intercept.mjs, provider logic in providers/, and the dashboard is a single dashboard.html. No build step, no bundler.

License

MIT