This page is also an MCP App. A web page cannot be an MCP server, so run the server (Node 20+, no install step) and add it to your host:

Launched by the host (stdio), for hosts with an mcpServers config:

{
  "mcpServers": {
    "lantern-grid": {
      "command": "npx",
      "args": ["-y", "github:kenchris/mcp-app-webmcp-demo", "--stdio"]
    }
  }
}

Over HTTP, for hosts that take a server URL:

npx -y github:kenchris/mcp-app-webmcp-demo --port 8787
# then add  http://127.0.0.1:8787/mcp

Then ask: "Start a Lantern Grid game and light all the lanterns." The model opens this view with start_game; if the host supports WebMCP in MCP Apps, it then plays with the tools the view registers (look, move, light_lantern, ...). A host without that support still shows the view, but the model will not see those tools.

Hosts that need a public https endpoint (for example ChatGPT) need the server behind a tunnel. More in the README.