NASA-MCP

Instructions

Implementation Reference

• src/nasa_mcp/server.py:274-314 (handler)

  The main handler function for the 'browse_asteroids' tool. It calls the NASA NEO browse API, processes the JSON response, and returns a formatted string summary of the first 10 near-Earth objects, including page info.
  async def browse_asteroids() -> str: """Browse the asteroid dataset.""" url = f"{NASA_API_BASE}/neo/rest/v1/neo/browse" data = await make_nasa_request(url) if not data: return "Could not retrieve asteroid dataset 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 Browse Asteroids API. URL: {data.get('url')}" try: near_earth_objects = data.get('near_earth_objects', []) page_info = f"Page {data.get('page', {}).get('number', 'Unknown')} of {data.get('page', {}).get('total_pages', 'Unknown')}" total_elements = f"Total elements: {data.get('page', {}).get('total_elements', 'Unknown')}" result = [page_info, total_elements, ""] # Limit the number of asteroids displayed to avoid excessive output display_limit = 10 count = 0 for asteroid in near_earth_objects: if count >= display_limit: result.append(f"n... and {len(near_earth_objects) - display_limit} more asteroids on this page.") break result.append(f"ID: {asteroid.get('id', 'Unknown')}") result.append(f"Name: {asteroid.get('name', 'Unknown')}") result.append(f"Absolute magnitude: {asteroid.get('absolute_magnitude_h', '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'}") result.append("-" * 40) count += 1 return "n".join(result) except Exception as e: logger.error(f"Error processing Browse Asteroids data: {str(e)}") return f"Error processing asteroid data: {str(e)}"
• src/nasa_mcp/server.py:28-83 (helper)

  Shared helper function used by browse_asteroids (and other tools) to make HTTP requests to NASA APIs, handle JSON/binary responses, errors, and add 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:274-274 (registration)

  The @mcp.tool() decorator registers the browse_asteroids function as an MCP tool.
  async def browse_asteroids() -> str: