relay-inspect

Stop copying and pasting console logs, server errors and screenshots into your CLI. Relay Inspect gives your AI coding agent direct access to your browser—so it can see what you see, verify its own changes, and debug without asking you to copy and paste.

Relay Inspect is a lightweight tool for designers and engineers who want to spend more time building and less time debugging.

                                                    ┌─ Chrome (CDP over WebSocket)
AI Coding Agent  ←→  Relay Inspect (MCP over stdio) ─┤
                                                    └─ Dev Servers (child processes)

Relay Inspect is a bridge between the Chrome DevTools Protocol, your dev server and your agent. It exposes browser state as MCP tools—console output, network requests, DOM queries and screenshots. Your agent edits code, the dev server hot reloads, and the agent verifies the result itself.

Looking for annotations? The browser annotation overlay has moved to its own package: Annoku.

Why Relay Inspect over Chrome DevTools MCP?

Google's Chrome DevTools MCP is a full browser automation tool—it clicks buttons, fills forms, runs Lighthouse audits, and scripts interactions. Relay Inspect gives agents continuous visibility while they work, so mistakes get caught in the moment, not at the end.

• Gives agents eyes. Real-time access to console output, network requests, and DOM state — so your agent sees what's happening as it happens, not after it's already moved on.

• Tight feedback loop. The edit → reload → verify cycle happens in a single turn. Your agent makes a change, waits for the dev server to reload, and immediately confirms it worked—without additional back-and-forth.

• Focused tools, fewer wrong turns. A handful of purpose-built tools means your agent reaches for the right one rather than thrashing through a broad API surface. Less noise, more signal.

• Zero overhead, zero telemetry. Connects lazily on the first tool call—no Puppeteer, no phoning home. Nothing runs until your agent needs it.

Related MCP server: Kaboom Browser AI Devtools MCP

Tools

Your agent gets access to the following tools automatically via MCP:

Browser Inspection

Page Control

Server Management

Diagnostics

Setup

Prerequisites

• Node.js 20+

• Chrome (or any Chromium-based browser)

Add to your MCP client

No install required — npx downloads and runs the package on first use.

Claude Code — add to .mcp.json or .claude/settings.json:

{
  "mcpServers": {
    "relay-inspect": {
      "command": "npx",
      "args": ["-y", "relay-inspect"]
    }
  }
}

Codex CLI:

codex mcp add relay-inspect -- npx -y relay-inspect

opencode — add to opencode.json:

{
  "mcp": {
    "relay-inspect": {
      "type": "local",
      "command": "npx",
      "args": ["-y", "relay-inspect"]
    }
  }
}

Chrome is auto-launched on first tool call if it isn't already running. To disable this or customize behavior, see Configuration below.

Configuration

If Chrome is already running with --remote-debugging-port, Relay Inspect will connect to it directly without launching a new instance.

Development

git clone https://github.com/samsolomon/relay-inspect.git
cd relay-inspect
npm install

npm run dev    # Run with tsx (auto-recompile)
npm run build  # Build with tsup
npm start      # Run the built bundle
npm test       # Run tests with vitest

For detailed architecture, conventions, and CDP implementation notes, see CLAUDE.md.