NASA MCP Server with pctx

This example demonstrates a custom MCP (Model Context Protocol) server built with the official @modelcontextprotocol/sdk that provides access to NASA APIs, deployed with pctx.

Features

The NASA MCP server provides 5 tools for accessing NASA data:

Asteroid Tools (NeoWs API)

1. search_asteroids - Search for Near Earth Objects based on their closest approach date
2. lookup_asteroid - Get detailed information about a specific asteroid by ID
3. browse_asteroids - Browse the overall NEO dataset with pagination

Satellite Tools (TLE API)

4. search_satellites - Search for satellites by name and get TLE data
5. lookup_satellite - Get TLE data for a specific satellite by catalog number

Architecture

• NASA MCP Server (port 3000): Custom MCP server that wraps NASA APIs
• pctx (port 8080): Exposes the NASA MCP server to AI models

Setup

1. Get a NASA API Key

Get your free API key at https://api.nasa.gov/

2. Install Dependencies

npm install

3. Configure Environment

Copy .env.example to .env and add your NASA API key:

cp .env.example .env

Edit .env:

NASA_API_KEY=your_key_here

Running Locally

Option 1: Using npm (with installed pctx)

npm start

This will:

1. Start the NASA MCP server on port 3000
2. Capture the auth token automatically
3. Start pctx on port 8080

Option 2: Using local cargo build

npm start -- --local

This uses cargo run to build and run pctx from source.

Option 3: Manual setup

Start the NASA MCP server:

node nasa-mcp-server.js

In another terminal, start pctx:

pctx start --port 8080 --config pctx.json

Testing

Test the NASA MCP server directly:

# List available tools
curl -X POST http://127.0.0.1:3000/mcp \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer YOUR_TOKEN' \
  -d '{"jsonrpc":"2.0","method":"tools/list","params":{},"id":1}'

# Search for asteroids
curl -X POST http://127.0.0.1:3000/mcp \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer YOUR_TOKEN' \
  -d '{"jsonrpc":"2.0","method":"tools/call","params":{"name":"search_asteroids","arguments":{"start_date":"2024-01-01"}},"id":2}'

# Search for satellites
curl -X POST http://127.0.0.1:3000/mcp \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer YOUR_TOKEN' \
  -d '{"jsonrpc":"2.0","method":"tools/call","params":{"name":"search_satellites","arguments":{"search":"ISS"}},"id":3}'

Test pctx:

curl -X POST http://127.0.0.1:8080/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","method":"initialize","params":{},"id":1}'

Deployment

Docker Compose

docker-compose up

Fly.io

1. Install the Fly CLI: https://fly.io/docs/hands-on/install-flyctl/

2. Login to Fly:

fly auth login

3. Set your NASA API key as a secret:

fly secrets set NASA_API_KEY=your_key_here

4. Deploy:

fly deploy

Your server will be available at https://nasa-pctx-example.fly.dev/mcp

API Documentation

NASA NeoWs API

• Documentation: https://api.nasa.gov/
• Rate limits: 1000 requests per hour with API key

TLE API

• Documentation: http://tle.ivanstanojevic.me
• No authentication required
• Data updated daily from CelesTrak

Example Tool Calls

Search Asteroids

{
  "name": "search_asteroids",
  "arguments": {
    "start_date": "2024-01-01",
    "end_date": "2024-01-02"
  }
}

Lookup Asteroid

{
  "name": "lookup_asteroid",
  "arguments": {
    "asteroid_id": "3542519"
  }
}

Browse Asteroids

{
  "name": "browse_asteroids",
  "arguments": {
    "page": 0,
    "size": 20
  }
}

Search Satellites

{
  "name": "search_satellites",
  "arguments": {
    "search": "ISS"
  }
}

Lookup Satellite

{
  "name": "lookup_satellite",
  "arguments": {
    "satellite_id": "25544"
  }
}

Troubleshooting

Port Already in Use

If ports 3000 or 8080 are already in use, you can change them:

NASA_MCP_PORT=3001 PCTX_PORT=8081 npm start

Connection Issues

Make sure both servers are running and the auth token is properly captured. Check the logs for any errors.

API Rate Limits

The NASA API has rate limits. If you're getting 429 errors, wait a bit or use your own API key instead of DEMO_KEY.

License

This example is provided as-is for demonstration purposes.