MCP Ecosystem — Model Context Protocol
Documentation: MCP Ecosystem — Model Context Protocol
MCP Ecosystem — Model Context Protocol
Open standard for connecting Claude Desktop (and other clients) to tools, data and workflows. Currently the main extension/plugin system of the Anthropic ecosystem.
Docs: https://modelcontextprotocol.io Spec: https://modelcontextprotocol.io/specification/latest Apps: https://modelcontextprotocol.io/extensions/apps/overview SDKs: https://modelcontextprotocol.io/docs/sdk
Architecture
MCP Host (Claude Desktop)
├── MCP Client 1 ←→ MCP Server A (local, stdio)
├── MCP Client 2 ←→ MCP Server B (remote, HTTP)
└── MCP Client N ←→ MCP Server N
- Host: AI application that coordinates MCP clients
- Client: Component that maintains connection with an MCP server
- Server: Program that provides context (tools, resources, prompts)
Primitives (Server → Client)
| Primitive | Type | Use |
|---|---|---|
| Tools | Executable | File ops, API calls, DB queries |
| Resources | Data | File contents, DB records, API responses |
| Prompts | Templates | System prompts, few-shot examples |
Primitives (Client → Server)
| Primitive | Type | Use |
|---|---|---|
| Sampling | Completion | Server requests completion from host LLM |
| Elicitation | Input | Server requests user input |
| Logging | Debug | Log messages for debugging |
MCP Apps (mais recente)
Extension that allows servers to return interactive HTML interfaces that render inside the chat.
How it works
- Tool description includes
_meta.ui.resourceUripointing toui://resource - Host preloads the resource before the tool is called
- Host fetches the HTML and renders in a sandboxed iframe
- App and host communicate via JSON-RPC (MCP dialect)
- App can call any MCP tool via postMessage
Use cases
- Complex data exploration (dashboards, maps)
- Multi-option configuration (forms)
- Rich media (PDFs, 3D models)
- Real-time monitoring
- Multi-step workflows
Client support
Claude Desktop, Claude.ai, VS Code Copilot, Microsoft 365 Copilot, Goose, Postman, MCPJam
Transport
- stdio: Local communication, no network overhead
- Streamable HTTP: POST + SSE, for remote servers, OAuth for auth
Security
- Sandboxed iframe — does not access host DOM, cookies, localStorage
- Communication via postMessage
- Host controls which capabilities the app can access
Custom MCP Server Construction
The existing LiteLLM gateway can serve as a foundation for:
- Notes MCP Server: Resources for notes, Tools for creating/searching/connecting
- Whiteboard MCP App: Interactive HTML interface with connection canvas
- Extract Selection Tool: Converts selected text into a note via postMessage
- Inline Comment Tool: Extracts comments from the harness and generates context
Connections
- claude-desktop-bundles — Harness architecture where MCP servers run
- claude-desktop-feature-flags — Feature flags that control MCP capabilities
- fitalabs-gateway-modelos — Existing gateway that can be extended as an MCP server