BLE MCP Transport

A Node.js BLE transport that enables MCP clients to communicate with MCP devices over BLE GATT. It relies on @abandonware/noble for scanning, connecting, and characteristic I/O, and includes JSON-RPC message framing for MTU-constrained links.

Features

• Scan and connect to peripherals by service UUID
• Bidirectional messaging via RX/TX characteristics
• Message packetization and reassembly for large payloads
• Compatible with the @modelcontextprotocol/sdk Transport interface

Quick Start

Install

npm i ble-mcp-transport

import { Client } from "@modelcontextprotocol/sdk/client/index.js";
import { BleTransport } from "ble-mcp-transport";

const transport = new BleTransport({
  scanTimeout: 10000,
});

const client = new Client(
  { name: "ble-mcp-client", version: "1.0.0" },
  { capabilities: {} }
);

await client.connect(transport);
const tools = await client.listTools();
console.log(tools);

Transport Options

BleTransport supports these optional settings:

• serviceUuid: Service UUID (defaults to the built-in value)
• rxCharUuid: RX characteristic UUID (defaults to the built-in value)
• txCharUuid: TX characteristic UUID (defaults to the built-in value)
• namePrefix: Peripheral name prefix filter
• scanTimeout: Scan timeout in milliseconds (default 10000)

Built-in UUIDs:

• Service: 00001999-0000-1000-8000-00805f9b34fb
• RX: 4963505f-5258-4000-8000-00805f9b34fb
• TX: 4963505f-5458-4000-8000-00805f9b34fb

Protocol and Framing

• Uses BLE GATT for communication
• RX characteristic: client writes messages
• TX characteristic: server notifies messages
• Start packet includes total length; subsequent packets increment sequence
• JSON-RPC messages are emitted after full reassembly

Development

npm run build

Requirements

• Node.js runtime
• A BLE adapter and appropriate OS permissions