NASA-MCP

Instructions

Implementation Reference

• src/nasa_mcp/server.py:154-209 (handler)

  The handler function for the 'get_asteroids_feed' tool. It queries the NASA NEO Feed API for asteroids within a date range, processes the response to extract details like ID, name, diameter, hazardous status, approach date, distance, and velocity, and returns a formatted string summary.

  async def get_asteroids_feed(start_date: str, end_date: str = None) -> str:
      """Get a list of asteroids based on their closest approach date to Earth.
      
      Args:
          start_date: Start date for asteroid search in YYYY-MM-DD format.
          end_date: End date for asteroid search in YYYY-MM-DD format. 
          The Feed date limit is only 7 Days. If not specified, 7 days after start_date is used.
      """
      params = {
          "start_date": start_date
      }
      
      if end_date:
          params["end_date"] = end_date
      
      url = f"{NASA_API_BASE}/neo/rest/v1/feed"
      data = await make_nasa_request(url, params)
      
      if not data:
          return "Could not retrieve asteroid data due to a connection error."
      
      # Check for error response (must be a dictionary)
      if isinstance(data, dict) and "error" in data:
          return f"API Error: {data.get('error')} - Details: {data.get('details', 'N/A')}"
      if isinstance(data, dict) and data.get("binary_content"):
          return f"Received unexpected binary content from Asteroids Feed API. URL: {data.get('url')}"
  
      try:
          element_count = data.get('element_count', 0)
          near_earth_objects = data.get('near_earth_objects', {})
          
          result = [f"Total asteroids found: {element_count}"]
          
          for date_str, asteroids in near_earth_objects.items():
              result.append(f"nDate: {date_str}")
              result.append(f"Number of asteroids: {len(asteroids)}")
              
              for asteroid in asteroids:
                  result.append(f"n  ID: {asteroid.get('id', 'Unknown')}")
                  result.append(f"  Name: {asteroid.get('name', 'Unknown')}")
                  result.append(f"  Estimated diameter (min): {asteroid.get('estimated_diameter', {}).get('kilometers', {}).get('estimated_diameter_min', 'Unknown')} km")
                  result.append(f"  Estimated diameter (max): {asteroid.get('estimated_diameter', {}).get('kilometers', {}).get('estimated_diameter_max', 'Unknown')} km")
                  result.append(f"  Potentially hazardous: {'Yes' if asteroid.get('is_potentially_hazardous_asteroid', False) else 'No'}")
                  
                  # Information about closest approach
                  close_approaches = asteroid.get('close_approach_data', [])
                  if close_approaches:
                      approach = close_approaches[0]
                      result.append(f"  Approach date: {approach.get('close_approach_date_full', 'Unknown')}")
                      result.append(f"  Distance (km): {approach.get('miss_distance', {}).get('kilometers', 'Unknown')}")
                      result.append(f"  Relative velocity (km/h): {approach.get('relative_velocity', {}).get('kilometers_per_hour', 'Unknown')}")
          
          return "n".join(result)
      except Exception as e:
          logger.error(f"Error processing Asteroids Feed data: {str(e)}")
          return f"Error processing asteroid data: {str(e)}"

• src/nasa_mcp/server.py:28-83 (helper)

  Shared helper function used by get_asteroids_feed (and other tools) to make HTTP requests to NASA APIs, handle JSON/binary responses, errors, and add the API key.

  async def make_nasa_request(url: str, params: dict = None) -> Union[dict[str, Any], List[Any], None]:
      """Make a request to the NASA API with proper error handling.
      Handles both JSON and binary (image) responses.
      """
      
      logger.info(f"Making request to: {url} with params: {params}")
      
      if params is None:
          params = {}
      
      # Ensure API key is included in parameters
      if "api_key" not in params:
          params["api_key"] = API_KEY
      
      async with httpx.AsyncClient() as client:
          try:
              response = await client.get(url, params=params, timeout=30.0, follow_redirects=True)
              response.raise_for_status() # Raise an exception for bad status codes (4xx or 5xx)
  
              content_type = response.headers.get("Content-Type", "").lower()
              
              if "application/json" in content_type:
                  try:
                      return response.json()
                  except json.JSONDecodeError as json_err:
                      logger.error(f"JSON decode error for URL {response.url}: {json_err}")
                      logger.error(f"Response text: {response.text[:500]}") # Log beginning of text
                      return {"error": "Failed to decode JSON response", "details": str(json_err)}
              elif content_type.startswith("image/"):
                  logger.info(f"Received binary image content ({content_type}) from {response.url}")
                  # Return a dictionary indicating binary content was received
                  return {
                      "binary_content": True, 
                      "content_type": content_type,
                      "url": str(response.url) # Return the final URL after redirects
                  }
              else:
                  # Handle other unexpected content types
                  logger.warning(f"Unexpected content type '{content_type}' received from {response.url}")
                  return {"error": f"Unexpected content type: {content_type}", "content": response.text[:500]}
  
          except httpx.HTTPStatusError as http_err:
              logger.error(f"HTTP error occurred: {http_err} - {http_err.response.status_code} for URL {http_err.request.url}")
              try:
                  # Try to get more details from response body if possible
                  error_details = http_err.response.json()
              except Exception:
                  error_details = http_err.response.text[:500]
              return {"error": f"HTTP error: {http_err.response.status_code}", "details": error_details}
          except httpx.RequestError as req_err:
              logger.error(f"Request error occurred: {req_err} for URL {req_err.request.url}")
              return {"error": "Request failed", "details": str(req_err)}
          except Exception as e:
              logger.error(f"An unexpected error occurred: {str(e)}")
              return {"error": "An unexpected error occurred", "details": str(e)}

• src/nasa_mcp/server.py:154-154 (registration)

  The @mcp.tool() decorator registers the get_asteroids_feed function as an MCP tool, using its signature and docstring for schema.

  async def get_asteroids_feed(start_date: str, end_date: str = None) -> str: