wattlayer-mcp

An MCP (Model Context Protocol) server that exposes WattLayer — East Asia power-data developer infrastructure ("the Stripe for Energy Data") — to LLM agents such as Claude Desktop and Cursor.

Ask your assistant things like "What's the current SMP?", "Score a 200 MW AI data center in Gyeonggi", or "Rank Korean regions for a renewable project" and it will call the WattLayer REST API for you.

Tools

| Tool | Arguments | Description | | ------------------- | ------------------------------------------------ | --------------------------------------------------------------------------- | | smp_latest | (none) | Latest System Marginal Price (wholesale electricity clearing price, KRW/kWh). | | supply_current | (none) | Real-time grid supply/demand snapshot (capacity, load, reserve rate). | | zones_get | code (string) | Distributed-energy (분산에너지) special zone detail by code. | | regions_scorecard | loadType (datacenter|factory|renewable) | Nationwide regional power-competitiveness ranking for a load type. | | siting_score | region (string), capacityMw (number), loadType | Siting & profitability intelligence for a proposed load at a region. |

Each tool calls the WattLayer REST API at https://api.wattlayer.io with the X-API-Key header and returns the JSON response.

Requirements

• Node.js >= 20
• A WattLayer API key (wl_live_... or wl_test_...) — get one at https://wattlayer.io.

Install & build

cd mcp
npm install
npm run build

This compiles src/index.ts to dist/index.js (an executable with a shebang).

For local development without building you can run it directly with tsx:

WATTLAYER_API_KEY=wl_live_xxx npm run dev

Configuration

The server is configured entirely through environment variables:

| Variable | Required | Default | Description | | -------------------- | -------- | --------------------------- | ------------------------------------ | | WATTLAYER_API_KEY | yes | — | Your WattLayer API key. | | WATTLAYER_BASE_URL | no | https://api.wattlayer.io | Override the API base URL (e.g. for local dev http://localhost:3000). |

Claude Desktop setup

Edit your claude_desktop_config.json:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Add a wattlayer entry under mcpServers (use the absolute path to the built dist/index.js):

{
  "mcpServers": {
    "wattlayer": {
      "command": "node",
      "args": ["C:\\Users\\A\\watt_layer\\mcp\\dist\\index.js"],
      "env": {
        "WATTLAYER_API_KEY": "wl_live_your_key_here"
      }
    }
  }
}

Once published to npm you can instead use npx with no build step:

{
  "mcpServers": {
    "wattlayer": {
      "command": "npx",
      "args": ["-y", "wattlayer-mcp"],
      "env": {
        "WATTLAYER_API_KEY": "wl_live_your_key_here"
      }
    }
  }
}

Restart Claude Desktop after saving. The WattLayer tools appear under the tools (🔌) menu.

Cursor setup

Create or edit .cursor/mcp.json in your project (or the global ~/.cursor/mcp.json):

{
  "mcpServers": {
    "wattlayer": {
      "command": "node",
      "args": ["C:\\Users\\A\\watt_layer\\mcp\\dist\\index.js"],
      "env": {
        "WATTLAYER_API_KEY": "wl_live_your_key_here"
      }
    }
  }
}

Then enable the wattlayer server in Cursor Settings → MCP.

Example prompts

• "Using WattLayer, what is the latest SMP right now?"
• "Get the current grid reserve rate."
• "Show me the Jeju distributed-energy zone (zones_get code=jeju)."
• "Rank all Korean regions for a renewable project."
• "Score a 300 MW data center in Chungnam."

Notes

• stdout is reserved for the MCP JSON-RPC protocol; the server logs diagnostics to stderr.
• Requests time out after 20 seconds.
• HTTP / auth errors from the API are returned as MCP tool errors with the status and body.

License

MIT