NASA-MCP

Instructions

Implementation Reference

• src/nasa_mcp/server.py:531-563 (handler)

  Handler function implementing the get_magnetopause_crossing tool. Queries NASA DONKI MPC API endpoint and formats results using shared helper.

  async def get_magnetopause_crossing(start_date: str = None, end_date: str = None) -> str:
      """Get magnetopause crossing (MPC) data.
      
      Args:
          start_date: Start date in YYYY-MM-DD format. Defaults to 30 days before current date.
          end_date: End date in YYYY-MM-DD format. Defaults to current date.
      """
      params = {}
      if start_date: params["startDate"] = start_date
      if end_date: params["endDate"] = end_date
      
      url = f"{NASA_API_BASE}/DONKI/MPC"
      data = await make_nasa_request(url, params)
  
      if not data: 
          return "Could not retrieve MPC 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 MPC API. URL: {data.get('url')}"
  
      try:
          # Ensure data is a list for format_donki_results
          if not isinstance(data, list):
              logger.error(f"Unexpected non-list response from MPC API: {data}")
              return "Received unexpected data format from MPC API."
              
          return format_donki_results(data, "Magnetopause Crossings", "mpcID")
      except Exception as e:
          logger.error(f"Error processing MPC data: {str(e)}")
          return f"Error processing magnetopause crossing data: {str(e)}"

• src/nasa_mcp/server.py:318-365 (helper)

  Shared helper function for formatting DONKI API results, used by get_magnetopause_crossing and other DONKI tools.

  def format_donki_results(data: list, title_prefix: str, id_key: str) -> str:
      if not data: 
          return f"No {title_prefix.lower()} data for the specified period."
      
      result = [f"{title_prefix} found: {len(data)}"]
      display_limit = 10
      count = 0
  
      for item in data:
          if count >= display_limit:
              result.append(f"n... and {len(data) - display_limit} more entries.")
              break
          
          result.append(f"nID: {item.get(id_key, 'Unknown')}")
          # Add common fields if they exist
          if 'startTime' in item: result.append(f"Start Time: {item.get('startTime', 'Unknown')}")
          if 'eventTime' in item: result.append(f"Event Time: {item.get('eventTime', 'Unknown')}")
          if 'sourceLocation' in item: result.append(f"Source Location: {item.get('sourceLocation', 'Unknown')}")
          if 'note' in item: result.append(f"Note: {item.get('note', 'N/A')}")
          if 'link' in item: result.append(f"Link: {item.get('link', 'N/A')}")
          
          # Specific fields for different DONKI types can be added here if needed
          # Example for CME:
          if id_key == 'activityID' and 'cmeAnalyses' in item:
              analyses = item.get('cmeAnalyses', [])
              if analyses:
                  result.append("  Analyses:")
                  for analysis in analyses[:2]: # Limit analyses shown
                      result.append(f"    - Time: {analysis.get('time21_5', 'N/A')}, Speed: {analysis.get('speed', 'N/A')} km/s, Type: {analysis.get('type', 'N/A')}")
          
          # Example for GST:
          if id_key == 'gstID' and 'allKpIndex' in item:
               kp_indices = item.get('allKpIndex', [])
               if kp_indices:
                   result.append("  Kp Indices (first 2):")
                   for kp in kp_indices[:2]:
                       result.append(f"    - Time: {kp.get('observedTime', 'N/A')}, Index: {kp.get('kpIndex', 'N/A')}")
  
          # Linked Events
          linked_events = item.get('linkedEvents', [])
          if linked_events:
              result.append("  Related event IDs (first 5):")
              result.append("    " + ", ".join([le.get('activityID', 'N/A') for le in linked_events[:5]]))
  
          result.append("-" * 40)
          count += 1
          
      return "n".join(result)

• src/nasa_mcp/server.py:28-82 (helper)

  General helper for making requests to NASA APIs, used by all tools including get_magnetopause_crossing.

  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:531-531 (registration)

  MCP tool registration decorator for get_magnetopause_crossing.

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