OpenVSP MCP Server

Instructions

Implementation Reference

• src/openvsp_mcp/tool.py:20-28 (handler)

  The handler function for the 'openvsp.inspect' tool, registered via FastMCP decorator. Extracts geometry_file from request and calls describe_geometry helper.

  @app.tool(
      name="openvsp.inspect",
      description=(
          "Describe an OpenVSP geometry without modifying it. Returns component IDs and raw info."),
      meta={"version": "0.1.0", "categories": ["geometry", "aero", "inspection"]},
  )
  def inspect(request: OpenVSPGeometryRequest) -> OpenVSPInspectResponse:
      return describe_geometry(request.geometry_file)

• src/openvsp_mcp/describe.py:14-62 (helper)

  Core helper function implementing the inspection logic: generates a no-op script, runs OpenVSP, checks exit code, parses .vsp3 XML to extract geometry IDs, wing names, and detailed component info.

  def describe_geometry(geometry_file: str) -> OpenVSPInspectResponse:
      """Run OpenVSP in describe mode and parse high-level geometry information."""
  
      with tempfile.TemporaryDirectory(prefix="openvsp_mcp_describe_") as tmpdir:
          temp_request = OpenVSPRequest(
              geometry_file=geometry_file,
              set_commands=[],
              run_vspaero=False,
              case_name="describe",
          )
          script_path = _write_script(temp_request, Path(tmpdir))
  
          result = subprocess.run(
              [OPENVSP_BIN, "-script", str(script_path)],
              check=False,
              capture_output=True,
          )
          if result.returncode not in _OK_EXIT_CODES:
              message = result.stderr.decode("utf-8", errors="ignore").strip()
              if not message:
                  message = result.stdout.decode("utf-8", errors="ignore").strip()
              raise RuntimeError(message or "OpenVSP describe run failed")
  
          tree = ET.parse(geometry_file)
          root = tree.getroot()
          geom_ids: list[str] = []
          wing_names: list[str] = []
          info_lines: list[str] = []
  
          for geom in root.findall(".//Geom"):
              name_elem = geom.find("ParmContainer/Name")
              geom_name = name_elem.text if name_elem is not None else ""
              id_elem = geom.find("ParmContainer/ID")
              geom_id = id_elem.text if id_elem is not None else ""
              type_elem = geom.find("GeomBase/TypeName")
              geom_type = type_elem.text if type_elem is not None else ""
  
              if geom_id:
                  geom_ids.append(geom_id)
              if geom_type.lower() == "wing" and geom_name:
                  wing_names.append(geom_name)
              info_lines.append(f"{geom_id or 'UNKNOWN'}:{geom_name or 'Unnamed'}:{geom_type or 'Unknown'}")
  
          return OpenVSPInspectResponse(
              geom_ids=geom_ids,
              wing_names=wing_names,
              info_log="\n".join(info_lines),
          )

• src/openvsp_mcp/models.py:14-16 (schema)

  Pydantic input schema for the openvsp.inspect tool request, requiring the path to the .vsp3 geometry file.

  class OpenVSPGeometryRequest(BaseModel):
      geometry_file: str = Field(..., description="Path to the .vsp3 file")

• src/openvsp_mcp/models.py:27-33 (schema)

  Pydantic output schema for the openvsp.inspect tool response, containing lists of geometry IDs and wing names, plus detailed info log.

  class OpenVSPInspectResponse(BaseModel):
      """High-level summary of a geometry."""
  
      geom_ids: list[str] = Field(..., description="Top-level geometry IDs discovered")
      wing_names: list[str] = Field(default_factory=list, description="Detected wing geometry names")
      info_log: str = Field(..., description="Raw output from OpenVSP describe command")

• src/openvsp_mcp/__main__.py:74-75 (registration)

  Invocation of build_tool on the FastMCP server instance, which registers the openvsp.inspect tool (along with others).

  build_tool(app)