MCPBrowser (MCP fetch tool with authenticated Chrome)

An MCP server that exposes an authenticated page fetch tool for GitHub Copilot. It drives your signed-in Chrome/Edge via DevTools, reusing your profile to read restricted pages.

Prereqs

• Chrome or Edge installed.

• Node 18+.

Install

Run (automatic via Copilot)

• Add the MCP server entry to VS Code settings (github.copilot.chat.modelContextProtocolServers, see below). Copilot will start the server automatically when it needs the tool—no manual launch required.

• On first use, the server auto-launches Chrome/Edge with remote debugging if it cannot find an existing DevTools endpoint. Defaults: port 9222, user data dir %LOCALAPPDATA%/ChromeAuthProfile. Override with CHROME_PATH, CHROME_USER_DATA_DIR, or CHROME_REMOTE_DEBUG_PORT.

• The old scripts/start-all.ps1 launcher was removed; Chrome startup is handled inside the MCP server.

Manual start (optional)

Only if you want to run it yourself (Copilot already starts it when configured):

Or manually:

Set CHROME_PATH if auto-detect fails; override profile with CHROME_USER_DATA_DIR, port with CHROME_REMOTE_DEBUG_PORT.

(Optional) Local runner

There is no local LLM runner now; Copilot provides the LLM and calls this MCP tool. If you need a standalone agent later, we can add one that reuses the fetch logic.

Use as a Copilot custom agent/tool (MCP server)

• This repo includes an MCP server exposing load_and_extract for GitHub Copilot in VS Code (loading is built-in). Copilot starts it automatically once registered.

• Optional manual start (not required when Copilot is configured):

• Attach in VS Code settings (github.copilot.chat.modelContextProtocolServers). Example entry (stored in %APPDATA%\Code\User\mcp.json on Windows or ~/.config/Code/User/mcp.json on Linux/Mac):

• In Copilot Chat, you should see the MCPBrowser server; ask it to load a URL and it will drive your signed-in Chrome session.

How it works

• Tool load_and_extract (inside the MCP server) drives your live Chrome (DevTools Protocol) so it inherits your auth cookies, returning text and html (truncated up to 2M chars per field) for analysis.

• Domain-aware tab reuse: Automatically reuses the same tab for URLs on the same domain, preserving authentication session. Different domains open new tabs.

• Automatic page loading: Waits for network idle (networkidle0) by default, ensuring JavaScript-heavy pages (SPAs, dashboards) fully load before returning content.

• Automatic auth detection: Detects ANY authentication redirect (domain changes, login/auth/sso/oauth URLs) and waits for you to complete sign-in, then returns to target page.

• Universal compatibility: Works with Microsoft, GitHub, AWS, Google, Okta, corporate SSO, or any authenticated site.

• Smart timeouts: 60s default for page load, 10 min for auth redirects. Tabs stay open indefinitely for reuse (no auto-close).

• GitHub Copilot's LLM invokes this tool via MCP; this repo itself does not run an LLM.

Auth-assisted fetch flow

• Copilot can call with just the URL, or with no params if you set an env default (DEFAULT_FETCH_URL or MCP_DEFAULT_FETCH_URL). By default tabs stay open indefinitely for reuse (domain-aware).

• First call opens the tab and leaves it open so you can sign in. No extra params needed.

• After you sign in, call the same URL again; tab stays open for reuse. Set keepPageOpen: false to close immediately on success.

• Optional fields (authWaitSelector, waitForSelector, waitForUrlPattern, etc.) are available but not required.

Configuration

• .env: optional overrides for CHROME_WS_ENDPOINT, CHROME_REMOTE_DEBUG_HOST/PORT, CHROME_PATH, CHROME_USER_DATA_DIR.

• To use a specific WS endpoint: set CHROME_WS_ENDPOINT from Chrome chrome://version DevTools JSON.

Tips

• Universal auth: Works with ANY authenticated site (Microsoft, GitHub, AWS, Google, corporate intranets, SSO, OAuth, etc.)

• No re-authentication needed: Automatically reuses the same tab for URLs on the same domain, keeping your auth session alive across multiple page fetches

• Automatic page loading: Tool waits for pages to fully load (default 60s timeout, waits for network idle). Copilot should trust the tool and not retry manually.

• Auth redirect handling: Auto-detects auth redirects by monitoring domain changes and common login URL patterns (/login, /auth, /signin, /sso, /oauth, /saml)

• Tabs stay open: By default tabs remain open indefinitely for reuse. Set keepPageOpen: false to close immediately after successful fetch.

• Smart domain switching: When switching domains, automatically closes the old tab and opens a new one to prevent tab accumulation

• If you hit login pages, verify Chrome instance is signed in and the site opens there.

• Use a dedicated profile directory to avoid interfering with your daily Chrome.

• For heavy pages, add waitForSelector to ensure post-login content appears before extraction.