webmcp-bridge

Overview

The webmcp-bridge provides a stable local bridge that allows MCP clients to call browser WebMCP tools, either through native WebMCP when available or through injected adapters when not. It maintains execution in the browser where capabilities like site authentication and human-AI collaboration already exist, while exposing a standard stdio MCP interface to local clients. The architecture supports both headless automation and visible browser windows for collaborative workflows.

Try asking AI

After installing, here are 5 things you can ask your AI assistant:

• bridge.open

  Opens a browser session for WebMCP collaboration

  Try:Open a browser session for the board demoTry:Start a visible browser session for human-AI collaboration
• bridge.close

  Closes the current browser session

  Try:Close the browser sessionTry:End the current WebMCP session
• diagram.get

  Retrieves the current board state as JSON

  Try:Get the current board stateTry:Show me the diagram as JSON
• diagram.loadDemo

  Loads a demo board configuration

  Try:Load the demo boardTry:Reset to demo diagram
• diagram.setTitle

  Sets the title of the current board

  Try:Set the board title to 'Project Plan'Try:Change diagram title
• diagram.export

  Exports the current board

  Try:Export the boardTry:Download the diagram
• nodes.create

  Creates a new node on the board

  Try:Create a new nodeTry:Add a node to the diagram
• nodes.update

  Updates an existing node on the board

  Try:Update this node with new textTry:Modify this node's properties
• nodes.delete

  Deletes a node from the board

  Try:Delete this nodeTry:Remove node from diagram
• edges.create

  Creates a connection between nodes

  Try:Create an edge between these nodesTry:Connect node A to node B
• selection.get

  Gets the currently selected elements

  Try:What's currently selected?Try:Show selection
• selection.remove

  Removes selected elements from the board

  Try:Remove the selected itemsTry:Delete selection

Comparable tools

Installation

# Install Playwright browsers first
npx playwright install

# Install from npm
npm install -g @webmcp-bridge/local-mcp

# Run directly
npx -y @webmcp-bridge/local-mcp --url https://board.holon.run --headless

# Or with uxc (recommended for stable shortcuts)
uxc link board-webmcp-ui "npx -y @webmcp-bridge/local-mcp --url https://board.holon.run --no-headless"

{
  "mcpServers": {
    "webmcp-bridge": {
      "command": "npx",
      "args": ["-y", "@webmcp-bridge/local-mcp", "--url", "https://board.holon.run"]
    }
  }
}

FAQ

What's the difference between native WebMCP and adapter mode?

Native WebMCP uses the site's existing implementation via browser navigator.modelContext, while adapter mode injects a shim that provides WebMCP functionality for sites that don't have it built-in.

Does it handle authentication?

The bridge assumes users are already authenticated in the browser session. It doesn't implement credential vaulting but can reuse existing logged-in browser profiles.

Compare webmcp-bridge with