cesium-mcp

Demo

https://github.com/user-attachments/assets/8a40565a-fcdd-47bf-ae67-bc870611c908

Packages & Entry Points

Module	Role	Status	Links
cesium-mcp-contracts	Transport-neutral names, descriptions, and JSON Schemas for browser tools	New shared layer	source
cesium-mcp-bridge	Protocol- and transport-free Cesium command executor (60+ commands)	Mainline, actively iterated	· source
cesium-mcp-webmcp	Native document.modelContext adapter for Cesium tool contracts	New browser adapter	source
examples/webmcp-integration	Focused npm + Vite integration without a chat UI or MCP server	Developer example	example
examples/browser-agent	Browser-only AI agent with automatic WebMCP exposure	Recommended	example · live demo
cesium-mcp-runtime	MCP server (stdio + HTTP)	Stable + MCP v2 preview	· source
cesium-mcp-dev	CesiumJS API knowledge base for coding assistants	Maintained	· source

Which one? Personal project or quick try → browser-agent. Let a compatible browser agent discover page-local Cesium tools → WebMCP. Existing web app embedding an AI assistant → bridge + your own function calling. Calling from Claude Desktop / Cursor / Dify → MCP runtime.

Architecture

flowchart LR
  subgraph clients ["AI Drivers (pick one)"]
    BA["Browser Agent\n(in the same page)"]
    WM["WebMCP Agent\n(browser-provided)"]
    FC["Your web app\nfunction calling"]
    MCP["Claude / Cursor / Dify\nvia MCP runtime"]
  end

  CONTRACTS["cesium-mcp-contracts\ntool definitions"]
  WEBMCP["cesium-mcp-webmcp\nnative adapter"]

  subgraph core ["cesium-mcp-bridge (browser)"]
    B["60+ tools\nprotocol-agnostic dispatcher"]
    C["CesiumJS Viewer"]
  end

  CONTRACTS -.-> BA
  CONTRACTS -.-> WEBMCP
  BA -- "in-page call" --> B
  WM -- "document.modelContext" --> WEBMCP
  WEBMCP --> B
  FC -- "in-page call" --> B
  MCP -- "WebSocket / JSON-RPC" --> B
  B --> C

  style clients fill:#1e293b,stroke:#528bff,color:#e2e8f0
  style core fill:#1e293b,stroke:#12B76A,color:#e2e8f0

The bridge remains the execution core, while contracts and protocol adapters stay separate. Pick whichever driver matches your scenario — they all reach the same Cesium command layer. On WebMCP-capable browsers, cesium-mcp-webmcp can expose 61 browser-safe commands in 12 selectable toolsets through document.modelContext without adding an MCP transport or backend server.

Quick Start

Path 0 — Try in 30 seconds (browser agent, recommended)

Open the live demo and ask—the hosted model is ready without a browser API key:

"Fly to the Eiffel Tower and drop a red marker"

Fork the examples/browser-agent folder to deploy your own.

Path 1 — Expose Cesium tools through WebMCP (Chrome 149+ experimental)

The browser-agent example automatically registers all 61 browser-safe page tools when document.modelContext is available. Its built-in chat uses automatic toolset routing to keep each normal request at 20 tools or fewer, while still offering explicit core, single-toolset, and all-61 modes:

npm run build -w packages/cesium-mcp-bridge
npm run build -w packages/cesium-mcp-webmcp
npx serve . -l 4173

Open http://localhost:4173/examples/browser-agent/, click Start, then inspect or execute the tools in DevTools → Application → WebMCP. Enable #enable-webmcp-testing and #devtools-webmcp-support in chrome://flags for local testing.

Application developers install the adapter separately. End users only open the integrated website; they do not install npm packages or run an MCP server.

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

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'], // add your own browser geocoder to expose this tool
})

// Later, if the page is unmounted:
registration.unregister()

See the WebMCP adapter API for custom integrations. For a complete npm + Vite application, start from the WebMCP integration example.

Path 2 — Embed in your own web app (function calling)

npm install cesium-mcp-bridge

import { CesiumBridge } from 'cesium-mcp-bridge';

const bridge = new CesiumBridge(viewer);
// Then: send the bridge's tool schema to any LLM that supports function/tool calling,
// route the model's tool calls to bridge.execute(name, params).

See examples/browser-agent/index.html for a complete loop with OpenAI-compatible APIs.

Path 3 — Use from Claude Desktop / Cursor / Dify (MCP)

Install bridge as in Path 2, then start the MCP runtime:

# Stable channel — npm latest (1.143.3)
npx cesium-mcp-runtime

# MCP v2 preview — npm next (1.143.4-next.0)
npx cesium-mcp-runtime@next

# HTTP mode; add @next to use the preview
npx cesium-mcp-runtime --transport http --port 3000
npx cesium-mcp-runtime@next --transport http --port 3000

The next preview serves existing MCP 2025-11-25 clients and the new 2026-07-28 protocol from the same stdio/HTTP entry. It uses the stable TypeScript SDK v2 and has passed the official server-stateless conformance scenario (28/28). The npm latest tag remains on 1.143.3, so you can switch back by removing @next. For matching preview package versions, install cesium-mcp-bridge@next in the browser application.

MCP client config:

{
  "mcpServers": {
    "cesium": {
      "command": "npx",
      "args": ["-y", "cesium-mcp-runtime"]
    }
  }
}

To test the preview from an MCP client, change the last argument to "cesium-mcp-runtime@next".

62 Available Command Tools

Tools are organized into 12 toolsets. Default mode enables 4 core toolsets (30 tools). Set CESIUM_TOOLSETS=all for everything, or let the AI discover and activate toolsets dynamically at runtime.

Canonical contracts: Tool descriptions default to English; set CESIUM_LOCALE=zh-CN for Chinese. Titles, behavior annotations, localized descriptions, defaults, and Runtime input validation all come from the shared JSON Schemas in cesium-mcp-contracts.