set_parameters

Instructions

Implementation Reference

• comsol_mcp/mcp_server.py:710-731 (handler)

  Definition of the 'set_parameters' MCP tool. Decorated with @mcp.tool(), it takes a JSON string of parameters, parses them, and sets each on the COMSOL model via model.java.param().set(name, expression). Returns updated parameters and count.

  @mcp.tool()
  def set_parameters(parameters_json: str) -> str:
      """Set multiple global parameters on the selected server-side model."""
  
      def _impl() -> dict[str, Any]:
          model = _require_model()
          parsed = json.loads(parameters_json)
          if not isinstance(parsed, list):
              raise ValueError("parameters_json must be a JSON array.")
          updated = []
          for item in parsed:
              if not isinstance(item, dict):
                  raise ValueError("Each parameter entry must be an object.")
              name = str(item.get("name", "")).strip()
              expression = str(item.get("expression", "")).strip()
              if not name:
                  raise ValueError("Parameter name is required.")
              model.java.param().set(name, expression)
              updated.append({"name": name, "expression": expression})
          return {"updated": updated, "count": len(updated)}
  
      return _run_tool("set_parameters", _impl)

• comsol_mcp/mcp_server.py:731-731 (registration)

  Registration call: return _run_tool('set_parameters', _impl) — triggers the tool via the runtime lock and error handling framework.

  return _run_tool("set_parameters", _impl)

• comsol_mcp/mcp_server.py:494-503 (helper)

  _run_tool helper — wraps the tool callback with logging, a runtime lock, error handling, and result formatting.

  def _run_tool(tool: str, callback) -> str:
      _setup_logging()
      with _runtime_lock:
          try:
              data = callback()
              return _tool_result(tool, True, data=data)
          except Exception as exc:
              logging.exception("Tool %s failed", tool)
              return _tool_result(tool, False, error=str(exc))

• comsol_mcp/mcp_server.py:467-492 (helper)

  _tool_result helper — formats the tool result JSON payload with success, data, error, server status, and appends to operations log.

  def _tool_result(tool: str, success: bool, data: dict[str, Any] | None = None, error: str = "") -> str:
      global _last_command, _last_error
      _last_command = tool
      _last_error = error
      payload = {
          "success": success,
          "tool": tool,
          "timestamp": time.time(),
          "datetime": _now_iso(),
          "server": _status_payload(),
          "data": data or {},
          "error": error,
          "log_path": str(SERVER_LOG),
          "operations_path": str(OPERATIONS_FILE),
      }
      _append_operation(
          {
              "tool": tool,
              "success": success,
              "error": error,
              "data": data or {},
          }
      )
      _write_status({"last_command": tool, "last_error": error})
      return _json(payload)