Lb Ui Proxy

An MCP (Model Context Protocol) proxy server that wraps the Longbroker OpenAPI MCP server and transforms its plain JSON responses into rich, interactive HTML dashboards — stock cards, candlestick charts, portfolio views, order forms, option chains, and more.

Built on the MCP-UI specification so any MCP host that renders ui:// resources (Goose, Claude Desktop, etc.) gets visual UIs instead of raw JSON.

Quick start

# 1. Install dependencies
npm install

# 2. Set your Longbridge token
export LONGBRIDGE_TOKEN="your_token_here"
# Generate a token at https://open.longbridge.com/connect

# 3. Run in dev mode (auto-restart on changes)
npm run dev

# 4. Or build and run production
npm run build
npm start

The server starts on http://localhost:3456 by default.

Docker

docker build -t lb-mcp-ui-proxy .
docker run -p 3456:3456 -e LONGBRIDGE_TOKEN=your_token lb-mcp-ui-proxy

Configuration

All config is via environment variables (see .env.example):

Variable	Default	Description
PORT	3456	Server listen port
LONGBRIDGE_MCP_URL	https://openapi.longbridge.com/mcp	Longbridge MCP backend URL
LONGBRIDGE_TOKEN	(required)	Bearer token for Longbridge API
LOG_LEVEL	info	Logging verbosity: debug, info, warn, error

How it works

┌──────────┐    MCP (Streamable HTTP)    ┌──────────────────┐    MCP (Streamable HTTP)    ┌──────────────────┐
│  MCP Host │ ◄───────────────────────► │  lb-mcp-ui-proxy  │ ◄───────────────────────► │  Longbridge MCP  │
│ (Goose,   │   ui:// HTML resources     │  (this server)    │   JSON tool calls          │  (openapi.       │
│  Claude)  │                            │                   │                            │   longbridge.com) │
└──────────┘                            └──────────────────┘                            └──────────────────┘

1. An MCP host connects to this proxy at POST /mcp using the Streamable HTTP transport.
2. The proxy exposes 11 UI-enhanced tools (prefixed lb_).
3. When the host calls a tool, the proxy:
   • Opens a session to the real Longbridge MCP server.
   • Forwards the tool call (e.g. get_quote → Longbridge).
   • Parses the JSON response.
   • Renders an interactive HTML dashboard via @mcp-ui/server's createUIResource.
   • Returns the HTML as a ui://longbridge/... resource that the host renders.

Tools

Proxy tool	Longbridge tool	UI
lb_quote	get_quote	Stock card with price, change, OHLCV, amplitude bar
lb_chart	get_candlesticks	Canvas-rendered candlestick chart with volume bars
lb_search	search_security	Search results table with symbol, name, exchange
lb_portfolio	get_account_summary + get_positions	Portfolio dashboard with P&L, positions table
lb_orders	get_orders	Orders table with status badges
lb_place_order	place_order	Interactive order form or direct order with confirmation
lb_option_chain	get_option_chain	Color-coded calls/puts table with Greeks
lb_alerts	get_alerts	Alerts list with toggle switches
lb_market_overview	get_market_status	Market indices and status (text)
lb_dca_plans	get_dca_plans	DCA plans dashboard with progress cards

Tool parameters

All tools accept their parameters as Zod-validated fields. Examples:

# Get a quote for Tesla
lb_quote(symbol: "TSLA.US")

# Candlestick chart
lb_chart(symbol: "TSLA.US", period: "1d", count: 100)

# Place a limit order
lb_place_order(symbol: "TSLA.US", side: "buy", type: "limit", price: 250.00, quantity: 10)

# Show the interactive order form
lb_place_order(_showForm: true)

API endpoints

Endpoint	Method	Description
/mcp	POST	MCP Streamable HTTP endpoint (session-based)
/health	GET	Health check — returns status, version, config check

Project structure

src/
├── index.ts               # Express server, MCP endpoint, session management
├── config.ts              # Environment variable config loader
├── longbridge-client.ts   # MCP client wrapper for Longbridge backend
├── tools/
│   └── register.ts        # Tool definitions — wires params → Longbridge → UI
└── ui/
    ├── styles.ts           # Shared CSS, HTML page wrapper, formatting helpers
    ├── quotes.ts           # Quote card + search results
    ├── chart.ts            # Candlestick chart (canvas)
    ├── portfolio.ts        # Portfolio dashboard + positions table
    ├── orders.ts           # Orders table + order form + confirmation
    ├── options.ts          # Option chain + price alerts
    └── dca.ts              # DCA plans dashboard

Development

# Dev server with hot reload
npm run dev

# Type-check only
npx tsc --noEmit

# Build for production
npm run build

Tech stack

• Runtime: Node.js 22, TypeScript (ESM)
• MCP SDK: @modelcontextprotocol/sdk (Streamable HTTP transport, both client and server)
• UI rendering: @mcp-ui/server (createUIResource with raw HTML)
• Web server: Express + CORS
• Validation: Zod (tool parameter schemas)
• Container: Docker (multi-stage build, Alpine)

License

Private — not yet licensed for distribution.