OpenVSP MCP Server

Instructions

Implementation Reference

• src/openvsp_mcp/tool.py:29-37 (handler)

  MCP handler function for openvsp.modify tool, registered with @app.tool and delegates to execute_openvsp with run_vspaero=False.
  @app.tool( name="openvsp.modify", description=( "Apply scripted parameter edits to an OpenVSP model without running VSPAero. " "Use set_commands to adjust geometry; returns the generated script path."), meta={"version": "0.1.0", "categories": ["geometry"]}, ) def modify(request: OpenVSPRequest) -> OpenVSPResponse: return execute_openvsp(request.model_copy(update={"run_vspaero": False}))
• src/openvsp_mcp/core.py:29-70 (helper)

  Core execution logic for OpenVSP modifications and optional VSPAero run, invoked by the tool handler.
  def execute_openvsp(request: OpenVSPRequest) -> OpenVSPResponse: """Run OpenVSP (and optionally VSPAero) using the provided request.""" with tempfile.TemporaryDirectory(prefix="openvsp_mcp_") as tmpdir: workdir = Path(tmpdir) script_path = _write_script(request, workdir) try: result = subprocess.run( [OPENVSP_BIN, "-script", str(script_path)], check=False, capture_output=True, ) except FileNotFoundError as exc: # pragma: no cover raise RuntimeError("OpenVSP binary not found") from exc 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() or "OpenVSP script execution failed" raise RuntimeError(message) vspaero_output: str | None = None if request.run_vspaero: try: aero = subprocess.run( [VSPAERO_BIN, request.geometry_file, request.case_name], check=False, capture_output=True, ) except FileNotFoundError as exc: # pragma: no cover raise RuntimeError("VSPAero binary not found") from exc if aero.returncode != 0: message = aero.stderr.decode("utf-8", errors="ignore").strip() if not message: message = aero.stdout.decode("utf-8", errors="ignore").strip() or "VSPAero execution failed" raise RuntimeError(message) vspaero_output = str(Path(request.case_name).with_suffix(".adb")) return OpenVSPResponse(script_path=str(script_path), result_path=vspaero_output)
• src/openvsp_mcp/models.py:18-25 (schema)

  Pydantic input model (OpenVSPRequest) defining parameters for openvsp.modify tool calls.
  class OpenVSPRequest(BaseModel): """Parameters controlling geometry edits and optional VSPAero run.""" geometry_file: str = Field(..., description="Path to the .vsp3 file") set_commands: list[VSPCommand] = Field(default_factory=list, description="Commands to run") run_vspaero: bool = Field(True, description="Execute VSPAero after editing geometry") case_name: str = Field("case", description="Base name for generated results")
• src/openvsp_mcp/models.py:35-43 (schema)

  Pydantic output model (OpenVSPResponse) for openvsp.modify tool responses.
  class OpenVSPResponse(BaseModel): """Response object capturing generated paths.""" script_path: str = Field(..., description="Absolute path to the temporary script file") result_path: str | None = Field( None, description="Path to the generated VSPAero .adb file (if run_vspaero=True)", )
• src/openvsp_mcp/core.py:79-103 (helper)

  Generates the OpenVSP script file from set_commands and model path, used in execute_openvsp.
  def _write_script(request: OpenVSPRequest, working_dir: Path) -> Path: script_path = working_dir / "automation.vspscript" commands: Iterable[VSPCommand] = request.set_commands or [] script_lines = [ "// Auto-generated by openvsp-mcp", "void main() {", " ClearVSPModel();", f" ReadVSPFile(\"{request.geometry_file}\");", ] for command in commands: script_lines.append(f" {_ensure_statement(command.command)}") script_lines.extend( [ " Update();", f" SetVSP3FileName(\"{request.geometry_file}\");", f" WriteVSPFile(\"{request.geometry_file}\", SET_ALL);", "}", ] ) script_path.write_text("\n".join(script_lines) + "\n", encoding="utf-8") return script_path