nvd_tool

Instructions

Implementation Reference

• src/mcp_nvd/server.py:47-68 (handler)

  The handler function for the 'nvd_tool' tool. It extracts the cve_id from arguments, instantiates NVD class, calls get_cve_list(), and returns the data as TextContent or None.

  @mcp.call_tool()
  async def nvd_tool(name: str, arguments: dict) -> Sequence[TextContent | ImageContent | EmbeddedResource]:
      """
      Fetch CVE data from NVD using the provided arguments.
  
      Args:
          cve_id (str): The CVE ID to fetch data for.
      """
      from mcp_nvd.nvd import NVD
      LOGGER.info(f"Fetching CVE data for {name} with arguments: {arguments}")
      cve_id = arguments.get("cve_id")
  
      nvd = NVD(cve_id=cve_id)
      cve_data = nvd.get_cve_list()
  
      if cve_data:
          # return cve_data
          return [TextContent(type="text", text=str(cve_data))]
      else:
          LOGGER.info(f"CVE {cve_id} not found in NVD database.")
          return None

• src/mcp_nvd/server.py:27-45 (registration)

  Registration of the 'nvd_tool' via the list_tools() callback, which returns the Tool object with name, description, and inputSchema.

  @mcp.list_tools()
  async def list_tools() -> list[types.Tool]:
      LOGGER.debug("Listing tools...")
      tools = [
          types.Tool(
              name="nvd_tool", description="Fetch CVE data from NVD",
              inputSchema={
                  "type": "object",
                  "properties": {
                      "cve_id": {
                          "type": "string",
                          "description": "The CVE ID to fetch data for."
                      }
                  },
                  "required": ["cve_id"]
              },
          )
      ]
      return tools

• src/mcp_nvd/server.py:33-42 (schema)

  Input schema defining the required 'cve_id' string parameter for the nvd_tool.

  inputSchema={
      "type": "object",
      "properties": {
          "cve_id": {
              "type": "string",
              "description": "The CVE ID to fetch data for."
          }
      },
      "required": ["cve_id"]
  },

• src/mcp_nvd/nvd.py:28-76 (helper)

  Helper method in NVD class that performs the actual HTTP request to NVD API to fetch CVE data based on cve_id.

  def get_cve_list(self) -> list:
      """
      Retrieve a specific CVE by its ID.
  
      Args:
          cve_id (str): The CVE ID (e.g. CVE-2025-12345)
      
      Returns:
          dict: CVE item or None if not found
      """
      params = {
          "cveId": self.cve_id,
      }
  
      LOGGER.info(f"Fetching CVE: {self.cve_id}...")
  
      try:
          response = requests.get(self.base_url, params=params)
  
          if response.status_code == 200:
              LOGGER.info(f"Response: {response.status_code}")
              data = response.json()
              vulnerabilities = data.get('vulnerabilities', [])
  
              if vulnerabilities:
                  self.cve_json = vulnerabilities[0]
                  self.description = self.get_description()
                  LOGGER.info(f"Description: {self.description}")
                  return vulnerabilities
              else:
                  LOGGER.info(f"CVE {self.cve_id} not found in NVD database.")
                  return None
              
          elif response.status_code == 403:
              print("Error: API rate limit exceeded. Please try again later.")
              return None
          elif response.status_code == 404:
              print("Error: API endpoint not found. Checking for diagnostic information...")
              print(f"Response: {response.text}")
              print("\nTrying alternative API endpoint...")
          else:
              print(f"Error: API returned status code {response.status_code}")
              print(f"Response: {response.text}")
              return None
  
      except Exception as e:
          print(f"Error: {e}")
          return None