Chrome Extension Bridge MCP

Overview

The Chrome Extension Bridge MCP is a lightweight bridge that lets an external Model Context Protocol (MCP) server communicate directly with any web page loaded in Chrome. By injecting a small client script into each tab, the extension opens a WebSocket channel to a locally running MCP server. This connection enables the server to read and modify page content, call JavaScript functions in the page context, and expose browser‑side APIs as MCP tools or resources. The result is a seamless way to orchestrate complex web interactions from an AI assistant or any external automation workflow.

Problem Solved

AI assistants often need to interact with live web applications—whether it’s manipulating a 3D editor, scraping data from a dashboard, or controlling a web‑based IDE. Traditional approaches rely on browser automation tools (e.g., Selenium) or custom APIs, which can be fragile and difficult to maintain. The Bridge MCP removes this friction by turning the browser itself into a first‑class MCP client, allowing any MCP server to treat a web page like a remote resource. This eliminates the need for bespoke adapters and keeps all logic in a single, well‑defined protocol.

Core Functionality

• Bidirectional WebSocket communication between the browser and server, ensuring low‑latency command execution.
• Tool registration that forwards calls from the MCP server to JavaScript functions in the page (e.g., or custom editor commands).
• Resource exposure that lets the server query properties of the page, such as , and retrieve DOM elements or other data.
• Unified transport layer that can be plugged into any MCP server implementation, keeping the bridge agnostic to the underlying transport (STDIO, TCP, etc.).

These capabilities allow developers to write a single MCP server that can control multiple tabs, query state from any page, and expose rich browser APIs to AI assistants without writing additional code for each target application.

Use Cases & Scenarios

• Automated UI testing: Run MCP‑driven test suites that interact with web UIs, capturing state and asserting conditions across multiple pages.
• Live editing of web applications: Control a three‑js editor or any in‑browser IDE by sending commands from an AI assistant, enabling instant code changes and previews.
• Data extraction: Pull structured data from dashboards or forms by exposing DOM queries as MCP resources, then process the results in a downstream AI workflow.
• Cross‑tab coordination: Use the MCP server to synchronize state between multiple tabs or windows, such as keeping a design canvas and its preview in sync.

Integration with AI Workflows

An MCP server powered by the Bridge extension can be wired into any AI assistant that understands the Model Context Protocol. The assistant sends tool calls or resource requests; the server forwards them to the appropriate web page via the extension, receives the result, and returns it back through MCP. This round‑trip can be used for real‑time code generation, debugging, or interactive tutorials that manipulate live web content on the fly.

Unique Advantages

• Zero‑install browser interaction: No need for external drivers or headless browsers; the extension runs in the user’s normal Chrome session.
• High performance: WebSocket communication is lightweight, making tool calls almost instantaneous even for complex page manipulations.
• Extensibility: Developers can expose any JavaScript function or property as an MCP tool/resource, turning existing web applications into fully programmable APIs with minimal effort.
• Security by design: The extension only opens a connection to a local server, limiting exposure to the developer’s machine and avoiding cross‑origin restrictions.

In summary, the Chrome Extension Bridge MCP transforms any web page into a programmable endpoint for AI assistants and automation scripts, offering developers a powerful, protocol‑driven interface to browser content without the overhead of traditional automation stacks.