cesium-mcp-webmcp

Native WebMCP registration for Cesium browser tools. This package owns only the document.modelContext adapter and uses transport-neutral contracts from cesium-mcp-contracts.

It does not include CesiumJS, the Cesium execution bridge, a backend MCP server, or a WebMCP polyfill.

Install

npm install cesium cesium-mcp-bridge cesium-mcp-webmcp

Usage

import { CesiumBridge } from 'cesium-mcp-bridge'
import { registerCesiumWebMcp } from 'cesium-mcp-webmcp'

const bridge = new CesiumBridge(viewer)
const registration = await registerCesiumWebMcp(bridge, {
  toolsets: 'all',
  excludeTools: ['geocode'],
})

// Remove only the tools owned by this registration.
registration.unregister()

registerCesiumWebMcp() defaults to the 15-contract core selection. Pass toolsets: 'all' for all 61 browser-safe tools, one toolset name, or an array such as ['view', 'entity', 'layer']. To register a custom contract subset, pass tools, or call the lower-level registerWebMcpTools() function.

import { registerCesiumWebMcp } from 'cesium-mcp-webmcp'

await registerCesiumWebMcp(bridge, {
  toolsets: ['view', 'entity', 'layer'],
})

An explicit tools array takes precedence over toolsets, and excludeTools removes individual contracts afterward. The Bridge directly executes 60 of the 61 browser-safe contracts. geocode needs an application-provided executor handler, as shown by the browser-agent example. setIonToken is never part of the browser-safe collection because credentials should remain application-owned.

The executor is structural: any object implementing execute({ action, params }) can be used. A backend cesium-mcp-runtime process is not required.

Browser bundle

The package also publishes a Cesium-free IIFE bundle:

<script src="./node_modules/cesium-mcp-webmcp/dist/cesium-mcp-webmcp.browser.global.js"></script>
<script>
  await CesiumMcpWebMcp.registerCesiumWebMcp(executor, { toolsets: 'all' })
</script>

The global is named CesiumMcpWebMcp. This package targets the native WebMCP API and deliberately does not install or bundle third-party polyfills.