READMEmain

Weather MCP Server

A serverless weather information service built on the Model Context Protocol (MCP) that runs as a Fleek edge function. This service provides weather alerts and forecasts using the National Weather Service (NWS) API.

Features

Weather Alerts: Get active weather alerts for any US state
Weather Forecasts: Get detailed weather forecasts for any US location by coordinates
MCP Integration: Use these weather tools through any MCP-compatible client

Installation

Prerequisites

Node.js v18 or newer
npm or yarn
A Fleek account for deployment

Getting Started

Clone this repository
Install dependencies:
```
npm install
```
Build the project:
```
npm run build
```

Deployment

Deploy to Fleek

Make sure you have the Fleek CLI installed:
```
npm install -g @fleek/cli
```
Login to your Fleek account:
```
fleek login
```
Deploy the function:
```
fleek functions deploy
```

Using the Weather MCP Server

The Weather MCP Server implements two main tools:

1. Get Weather Alerts

Retrieve active weather alerts for any US state.

Parameters:

state: Two-letter state code (e.g., CA, NY, TX)

Example:

{
  "type": "tool_call",
  "name": "get-alerts",
  "parameters": {
    "state": "CA"
  }
}

2. Get Weather Forecast

Retrieve weather forecasts for any US location by coordinates.

Parameters:

latitude: Latitude of the location (-90 to 90)
longitude: Longitude of the location (-180 to 180)

Example:

{
  "type": "tool_call",
  "name": "get-forecast",
  "parameters": {
    "latitude": 39.7456,
    "longitude": -75.5466
  }
}

API Endpoints

The function exposes several endpoints:

GET /sse: Establish a Server-Sent Events connection
POST /messages?connectionId={id}: Send messages to the MCP server
GET /poll?connectionId={id}: Poll for message responses

Connection Flow

Connect to the SSE endpoint:
```
GET /sse
```
This returns a connectionId in the SSE stream.

Send a tool request:

POST /messages?connectionId={your_connection_id}
Content-Type: application/json

{
  "type": "tool_call",
  "name": "get-forecast",
  "parameters": {
    "latitude": 39.7456,
    "longitude": -75.5466
  }
}

Poll for responses:
```
GET /poll?connectionId={your_connection_id}
```
This returns any pending messages as SSE events.

Example: Get Weather for Delaware

To get the weather forecast for Wilmington, Delaware:

Connect to SSE and get a connection ID
Send a request with these coordinates:
- Latitude: 39.7456 (Wilmington, DE)
- Longitude: -75.5466 (Wilmington, DE)

Limitations

Only works for US locations (NWS API limitation)
In-memory state management (connections may be lost between function invocations)
Edge function timeout limits may affect long-running connections

Development

Local Testing

Test the API using curl or Postman:

# Connect to SSE
curl -N http://localhost:8787/sse

# Send a request (in another terminal)
curl -X POST http://localhost:8787/messages?connectionId=YOUR_CONNECTION_ID \
  -H "Content-Type: application/json" \
  -d '{"type":"tool_call","name":"get-forecast","parameters":{"latitude":39.7456,"longitude":-75.5466}}'

# Poll for messages
curl -N http://localhost:8787/poll?connectionId=YOUR_CONNECTION_ID

MCP Integration

This server implements the Model Context Protocol, allowing it to be used with any MCP-compatible client. See the MCP documentation for more details.

mcp-edge-functions