diff --git a/gns3server/agent/gns3_copilot/agent/gns3_copilot.py b/gns3server/agent/gns3_copilot/agent/gns3_copilot.py
index a9616eb8b..ac784cab0 100644
--- a/gns3server/agent/gns3_copilot/agent/gns3_copilot.py
+++ b/gns3server/agent/gns3_copilot/agent/gns3_copilot.py
@@ -527,7 +527,7 @@ def tool_node(state: dict, config: RunnableConfig | None = None):
             )
         except Exception as e:
             logger.error("Tool %s failed: %s", tool_name, e, exc_info=True)
-            observation = f"Error: {str(e)}"
+            observation = f"Error: {e!s}"
 
         # Serialize observation to JSON string if it's not already a string
         # This ensures ToolMessage.content is always JSON format, not Python
diff --git a/gns3server/agent/gns3_copilot/gns3_client/connector.py b/gns3server/agent/gns3_copilot/gns3_client/connector.py
index 40ce1c5e5..21f7fc58d 100644
--- a/gns3server/agent/gns3_copilot/gns3_client/connector.py
+++ b/gns3server/agent/gns3_copilot/gns3_client/connector.py
@@ -175,7 +175,7 @@ class Gns3Connector:
             else:
                 raise HTTPError(f"v3 API authentication failed: {response.status_code} - {response.text}")
         except Exception as e:
-            raise HTTPError(f"v3 API authentication error: {str(e)}") from e
+            raise HTTPError(f"v3 API authentication error: {e!s}") from e
 
     def _is_token_expired(self) -> bool:
         """
@@ -273,7 +273,7 @@ class Gns3Connector:
         except Exception:
             # If JSON parsing fails, return error with original text
             return HTTPError(
-                f"Original Error: {str(e)}. GNS3 response text: {response.text}",
+                f"Original Error: {e!s}. GNS3 response text: {response.text}",
                 response=response,
             )
         return e
diff --git a/gns3server/agent/gns3_copilot/gns3_client/gns3_project_info.py b/gns3server/agent/gns3_copilot/gns3_client/gns3_project_info.py
index 9b699e51f..3ed793580 100644
--- a/gns3server/agent/gns3_copilot/gns3_client/gns3_project_info.py
+++ b/gns3server/agent/gns3_copilot/gns3_client/gns3_project_info.py
@@ -143,7 +143,7 @@ class GNS3ProjectInfoTool(BaseTool):
 
         except Exception as e:
             logger.error("Error retrieving GNS3 project info: %s", str(e))
-            return {"error": f"Failed to retrieve project info: {str(e)}"}
+            return {"error": f"Failed to retrieve project info: {e!s}"}
 
 
 if __name__ == "__main__":
diff --git a/gns3server/agent/gns3_copilot/gns3_client/gns3_topology_reader.py b/gns3server/agent/gns3_copilot/gns3_client/gns3_topology_reader.py
index ce5449079..208d7074f 100644
--- a/gns3server/agent/gns3_copilot/gns3_client/gns3_topology_reader.py
+++ b/gns3server/agent/gns3_copilot/gns3_client/gns3_topology_reader.py
@@ -145,7 +145,7 @@ class GNS3TopologyTool(BaseTool):
 
         except Exception as e:
             logger.error("Error retrieving GNS3 topology: %s", str(e))
-            return {"error": f"Failed to retrieve topology: {str(e)}"}
+            return {"error": f"Failed to retrieve topology: {e!s}"}
 
     def _clean_nodes_ports(self, data: dict) -> dict:
         """
diff --git a/gns3server/agent/gns3_copilot/skills/registry.py b/gns3server/agent/gns3_copilot/skills/registry.py
index d9e2b5083..aa67cd51b 100644
--- a/gns3server/agent/gns3_copilot/skills/registry.py
+++ b/gns3server/agent/gns3_copilot/skills/registry.py
@@ -239,7 +239,7 @@ def reload_injection_skills() -> dict[str, Any]:
         logger.error(f"Error during skills reload: {e}")
         return {
             "success": False,
-            "message": f"Error: {str(e)}",
+            "message": f"Error: {e!s}",
             "skill_count": len(INJECTION_SKILLS_REGISTRY),
             "version": "",
         }
@@ -278,7 +278,7 @@ def reload_prompts() -> dict[str, Any]:
         manager = get_skills_manager()
         return {
             "success": False,
-            "message": f"Error: {str(e)}",
+            "message": f"Error: {e!s}",
             "prompt_count": manager.get_prompt_count() if manager else 0,
             "version": "",
         }
@@ -314,7 +314,7 @@ def reload_forbidden_commands() -> dict[str, Any]:
         }
     except Exception as e:
         logger.error(f"Error during forbidden commands reload: {e}")
-        return {"success": False, "message": f"Error: {str(e)}", "command_count": 0, "version": ""}
+        return {"success": False, "message": f"Error: {e!s}", "command_count": 0, "version": ""}
 
 
 def get_prompt(prompt_name: str) -> str:
diff --git a/gns3server/agent/gns3_copilot/tools_v2/config_tools_nornir.py b/gns3server/agent/gns3_copilot/tools_v2/config_tools_nornir.py
index 6b96e6202..250fb559d 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/config_tools_nornir.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/config_tools_nornir.py
@@ -255,7 +255,7 @@ class ExecuteMultipleDeviceConfigCommands(BaseTool):
         except Exception as e:
             # Overall execution failed
             logger.error("Error executing configurations on all devices: %s", e)
-            return [{"status": "failed", "error": f"Execution error: {str(e)}"}]
+            return [{"status": "failed", "error": f"Execution error: {e!s}"}]
 
         logger.info(
             "Multiple device configuration execution completed. Results: %s",
@@ -285,7 +285,7 @@ class ExecuteMultipleDeviceConfigCommands(BaseTool):
             )
             return Result(
                 host=task.host,
-                result=f"Configuration failed (ReadTimeout): {str(e)}",
+                result=f"Configuration failed (ReadTimeout): {e!s}",
                 failed=True,
             )
 
@@ -305,7 +305,7 @@ class ExecuteMultipleDeviceConfigCommands(BaseTool):
             )
             return Result(
                 host=task.host,
-                result=f"Configuration failed (Unhandled Exception): {str(e)}",
+                result=f"Configuration failed (Unhandled Exception): {e!s}",
                 failed=True,
             )
 
diff --git a/gns3server/agent/gns3_copilot/tools_v2/display_tools_nornir.py b/gns3server/agent/gns3_copilot/tools_v2/display_tools_nornir.py
index 206ca10ea..ab31e9978 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/display_tools_nornir.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/display_tools_nornir.py
@@ -253,7 +253,7 @@ class ExecuteMultipleDeviceCommands(BaseTool):
         except Exception as e:
             # Overall execution failed
             logger.error("Error executing display on all devices: %s", e)
-            return [{"status": "failed", "error": f"Execution error: {str(e)}"}]
+            return [{"status": "failed", "error": f"Execution error: {e!s}"}]
 
         logger.debug(
             "Multiple device display execution completed. Results: %s",
@@ -288,7 +288,7 @@ class ExecuteMultipleDeviceCommands(BaseTool):
             )
             return Result(
                 host=task.host,
-                result=f"diagnostic command failed (ReadTimeout): {str(e)}",
+                result=f"diagnostic command failed (ReadTimeout): {e!s}",
                 failed=True,
             )
 
@@ -313,7 +313,7 @@ class ExecuteMultipleDeviceCommands(BaseTool):
             )
             return Result(
                 host=task.host,
-                result=f"diagnostic command failed (Unhandled): {str(e)}",
+                result=f"diagnostic command failed (Unhandled): {e!s}",
                 failed=True,
             )
 
diff --git a/gns3server/agent/gns3_copilot/tools_v2/gns3_create_link.py b/gns3server/agent/gns3_copilot/tools_v2/gns3_create_link.py
index ff11c6a44..c70c559ba 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/gns3_create_link.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/gns3_create_link.py
@@ -238,7 +238,7 @@ class GNS3LinkTool(BaseTool):
                     created_links.append(link_info)
 
                 except Exception as e:
-                    error_msg = f"Failed to create link {i}: {str(e)}"
+                    error_msg = f"Failed to create link {i}: {e!s}"
                     logger.error(error_msg)
                     created_links.append({"error": error_msg})
 
@@ -257,7 +257,7 @@ class GNS3LinkTool(BaseTool):
             return [{"error": f"Invalid JSON input: {e}"}]
         except Exception as e:
             logger.error("Failed to process link creation: %s", e)
-            return [{"error": f"Failed to process link creation: {str(e)}"}]
+            return [{"error": f"Failed to process link creation: {e!s}"}]
 
 
 if __name__ == "__main__":
diff --git a/gns3server/agent/gns3_copilot/tools_v2/gns3_create_node.py b/gns3server/agent/gns3_copilot/tools_v2/gns3_create_node.py
index bdbc0bf42..60b2b0801 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/gns3_create_node.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/gns3_create_node.py
@@ -244,7 +244,7 @@ class GNS3CreateNodeTool(BaseTool):
 
                 except Exception as e:
                     error_info = {
-                        "error": f"Node {i + 1} creation failed: {str(e)}",
+                        "error": f"Node {i + 1} creation failed: {e!s}",
                         "status": "failed",
                     }
                     results.append(error_info)
@@ -280,7 +280,7 @@ class GNS3CreateNodeTool(BaseTool):
             return {"error": f"Invalid JSON input: {e}"}
         except Exception as e:
             logger.error("Failed to process node creation request: %s", e)
-            return {"error": f"Failed to process node creation request: {str(e)}"}
+            return {"error": f"Failed to process node creation request: {e!s}"}
 
 
 if __name__ == "__main__":
diff --git a/gns3server/agent/gns3_copilot/tools_v2/gns3_get_node_temp.py b/gns3server/agent/gns3_copilot/tools_v2/gns3_get_node_temp.py
index af685ea4b..594c2c2cf 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/gns3_get_node_temp.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/gns3_get_node_temp.py
@@ -168,7 +168,7 @@ class GNS3TemplateTool(BaseTool):
 
         except Exception as e:
             logger.error("Failed to connect to GNS3 server or retrieve templates: %s", e)
-            return {"error": f"Failed to retrieve templates: {str(e)}"}
+            return {"error": f"Failed to retrieve templates: {e!s}"}
 
 
 if __name__ == "__main__":
diff --git a/gns3server/agent/gns3_copilot/tools_v2/gns3_packet_filter.py b/gns3server/agent/gns3_copilot/tools_v2/gns3_packet_filter.py
index be7af824f..ed563cbbd 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/gns3_packet_filter.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/gns3_packet_filter.py
@@ -239,7 +239,7 @@ class GNS3PacketFilterTool(BaseTool):
             return {"error": f"Invalid JSON input: {e}"}
         except Exception as e:
             logger.error("Failed to process packet filter request: %s", e)
-            return {"error": f"Failed to process packet filter request: {str(e)}"}
+            return {"error": f"Failed to process packet filter request: {e!s}"}
 
     def _get_available_filters(self, gns3_ctx: dict, project_id: str, link_id: str) -> dict[str, Any]:
         """Get available filter types for the link."""
@@ -260,7 +260,7 @@ class GNS3PacketFilterTool(BaseTool):
             return {
                 "action": "get_available",
                 "link_id": link_id,
-                "error": f"Failed to get available filters: {str(e)}",
+                "error": f"Failed to get available filters: {e!s}",
                 "status": "failed",
             }
 
@@ -318,7 +318,7 @@ class GNS3PacketFilterTool(BaseTool):
 
         except Exception as e:
             logger.error("Unexpected error during BPF validation: %s", e)
-            return {"valid": False, "error": f"BPF validation error: {str(e)}"}
+            return {"valid": False, "error": f"BPF validation error: {e!s}"}
 
     def _set_filters(
         self,
@@ -384,7 +384,7 @@ class GNS3PacketFilterTool(BaseTool):
             return {
                 "action": "set",
                 "link_id": link_id,
-                "error": f"Failed to set filters: {str(e)}",
+                "error": f"Failed to set filters: {e!s}",
                 "status": "failed",
             }
 
@@ -407,7 +407,7 @@ class GNS3PacketFilterTool(BaseTool):
             return {
                 "action": "get",
                 "link_id": link_id,
-                "error": f"Failed to get filters: {str(e)}",
+                "error": f"Failed to get filters: {e!s}",
                 "status": "failed",
             }
 
@@ -449,7 +449,7 @@ class GNS3PacketFilterTool(BaseTool):
             return {
                 "action": "clear",
                 "link_id": link_id,
-                "error": f"Failed to clear filters: {str(e)}",
+                "error": f"Failed to clear filters: {e!s}",
                 "status": "failed",
             }
 
diff --git a/gns3server/agent/gns3_copilot/tools_v2/gns3_start_node.py b/gns3server/agent/gns3_copilot/tools_v2/gns3_start_node.py
index 4086cde1b..2fb17f8f8 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/gns3_start_node.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/gns3_start_node.py
@@ -220,7 +220,7 @@ class GNS3StartNodeTool(BaseTool):
             return {"error": f"Invalid JSON input: {e}"}
         except Exception as e:
             logger.error("Failed to start nodes: %s", e)
-            return {"error": f"Failed to start nodes: {str(e)}"}
+            return {"error": f"Failed to start nodes: {e!s}"}
 
 
 # Backward-compat alias: the waiting variant was removed; both names now
diff --git a/gns3server/agent/gns3_copilot/tools_v2/gns3_stop_node.py b/gns3server/agent/gns3_copilot/tools_v2/gns3_stop_node.py
index d6965f19b..b4ef8cfd5 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/gns3_stop_node.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/gns3_stop_node.py
@@ -198,7 +198,7 @@ class GNS3StopNodeTool(BaseTool):
             return {"error": f"Invalid JSON input: {e}"}
         except Exception as e:
             logger.error("Failed to stop nodes: %s", e)
-            return {"error": f"Failed to stop nodes: {str(e)}"}
+            return {"error": f"Failed to stop nodes: {e!s}"}
 
 
 if __name__ == "__main__":
diff --git a/gns3server/agent/gns3_copilot/tools_v2/gns3_suspend_node.py b/gns3server/agent/gns3_copilot/tools_v2/gns3_suspend_node.py
index 47a0cc4b1..25dda50fd 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/gns3_suspend_node.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/gns3_suspend_node.py
@@ -209,7 +209,7 @@ class GNS3SuspendNodeTool(BaseTool):
             return {"error": f"Invalid JSON input: {e}"}
         except Exception as e:
             logger.error("Failed to suspend nodes: %s", e)
-            return {"error": f"Failed to suspend nodes: {str(e)}"}
+            return {"error": f"Failed to suspend nodes: {e!s}"}
 
 
 if __name__ == "__main__":
diff --git a/gns3server/agent/gns3_copilot/tools_v2/gns3_update_node_name.py b/gns3server/agent/gns3_copilot/tools_v2/gns3_update_node_name.py
index 7756b33a2..3121bc598 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/gns3_update_node_name.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/gns3_update_node_name.py
@@ -241,7 +241,7 @@ class GNS3UpdateNodeNameTool(BaseTool):
             return {"error": f"Invalid JSON input: {e}"}
         except Exception as e:
             logger.error("Failed to update node names: %s", e)
-            return {"error": f"Failed to update node names: {str(e)}"}
+            return {"error": f"Failed to update node names: {e!s}"}
 
 
 if __name__ == "__main__":
diff --git a/gns3server/agent/gns3_copilot/tools_v2/gns3_wait.py b/gns3server/agent/gns3_copilot/tools_v2/gns3_wait.py
index 15a9ed24e..ed2f12802 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/gns3_wait.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/gns3_wait.py
@@ -104,4 +104,4 @@ class GNS3WaitTool(BaseTool):
             return {"error": f"Invalid JSON input: {e}"}
         except Exception as e:
             logger.error("Wait tool failed: %s", e)
-            return {"error": f"Wait tool failed: {str(e)}"}
+            return {"error": f"Wait tool failed: {e!s}"}
diff --git a/gns3server/agent/gns3_copilot/tools_v2/packet_analysis_tool.py b/gns3server/agent/gns3_copilot/tools_v2/packet_analysis_tool.py
index c5f30bf79..5aacb0ed7 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/packet_analysis_tool.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/packet_analysis_tool.py
@@ -325,7 +325,7 @@ class PacketAnalysisTool(BaseTool):
 
         except Exception as e:
             logger.error(f"PacketAnalysisTool error: {e}", exc_info=True)
-            return f'{{"error": "Analysis failed: {str(e)}"}}'
+            return f'{{"error": "Analysis failed: {e!s}"}}'
 
         finally:
             # Clean up temp file
@@ -497,7 +497,7 @@ class PacketAnalysisTool(BaseTool):
             return '{"error": "tshark not installed. Please install tshark: apt install tshark"}'
         except Exception as e:
             logger.error(f"tshark execution error: {e}", exc_info=True)
-            return f'{{"error": "tshark failed: {str(e)}"}}'
+            return f'{{"error": "tshark failed: {e!s}"}}'
 
 
 if __name__ == "__main__":
diff --git a/gns3server/agent/gns3_copilot/tools_v2/vpcs_tools_netmiko.py b/gns3server/agent/gns3_copilot/tools_v2/vpcs_tools_netmiko.py
index d9186d2d4..26a512dc5 100644
--- a/gns3server/agent/gns3_copilot/tools_v2/vpcs_tools_netmiko.py
+++ b/gns3server/agent/gns3_copilot/tools_v2/vpcs_tools_netmiko.py
@@ -227,7 +227,7 @@ class VPCSCommands(BaseTool):
         except Exception as e:
             # Overall execution failed
             logger.error("Error executing commands on all VPCS devices: %s", e)
-            return [{"status": "failed", "error": f"Execution error: {str(e)}"}]
+            return [{"status": "failed", "error": f"Execution error: {e!s}"}]
 
         logger.debug(
             "VPCS command execution completed. Results: %s",
@@ -262,7 +262,7 @@ class VPCSCommands(BaseTool):
             )
             return Result(
                 host=task.host,
-                result=f"Command failed (ReadTimeout): {str(e)}",
+                result=f"Command failed (ReadTimeout): {e!s}",
                 failed=True,
             )
 
@@ -289,7 +289,7 @@ class VPCSCommands(BaseTool):
                 )
                 return Result(
                     host=task.host,
-                    result=f"Command failed: {str(retry_e)}",
+                    result=f"Command failed: {retry_e!s}",
                     failed=True,
                 )
 
diff --git a/gns3server/agent/gns3_copilot/utils/parse_tool_content.py b/gns3server/agent/gns3_copilot/utils/parse_tool_content.py
index 350a6bf50..736d792c3 100644
--- a/gns3server/agent/gns3_copilot/utils/parse_tool_content.py
+++ b/gns3server/agent/gns3_copilot/utils/parse_tool_content.py
@@ -496,7 +496,7 @@ def _test_parse_tool_content() -> None:
     for i, (input_data, expected) in enumerate(test_cases):
         result = parse_tool_content(input_data)
         status = "✓" if result == expected else "✗"
-        print(f"Test {i + 1}: {status} Input: {repr(input_data)} -> {result}")
+        print(f"Test {i + 1}: {status} Input: {input_data!r} -> {result}")
 
     print("\nTesting format_tool_response function:")
     format_tests = [
@@ -518,7 +518,7 @@ def _test_parse_tool_content() -> None:
             valid = "✓"
         except Exception:
             valid = "✗"
-        print(f"Format Test {i + 1}: {valid} Input: {repr(input_data)} -> {result}")
+        print(f"Format Test {i + 1}: {valid} Input: {input_data!r} -> {result}")
 
 
 if __name__ == "__main__":
diff --git a/gns3server/compute/docker/docker_vm.py b/gns3server/compute/docker/docker_vm.py
index 08559b990..4bb9b4344 100644
--- a/gns3server/compute/docker/docker_vm.py
+++ b/gns3server/compute/docker/docker_vm.py
@@ -1468,7 +1468,7 @@ class DockerVM(BaseNode):
                     pass
         # Ignore runtime error because when closing the server
         except RuntimeError as e:
-            log.debug(f"Docker runtime error when closing: {str(e)}")
+            log.debug(f"Docker runtime error when closing: {e!s}")
             return
         self.status = "stopped"
 
@@ -1571,7 +1571,7 @@ class DockerVM(BaseNode):
                                 self.manager.port_manager.release_udp_port(nio.lport, self._project)
         # Ignore runtime error because when closing the server
         except (DockerHttp404Error, RuntimeError) as e:
-            log.debug(f"Docker error when closing: {str(e)}")
+            log.debug(f"Docker error when closing: {e!s}")
             return
 
     def _get_container_ifname(self, adapter_number):
@@ -1775,7 +1775,7 @@ class DockerVM(BaseNode):
 
         for index in range(4096):
             if f"tap-gns3-e{index}" not in psutil.net_if_addrs():
-                adapter.host_ifc = f"tap-gns3-e{str(index)}"
+                adapter.host_ifc = f"tap-gns3-e{index!s}"
                 break
         if adapter.host_ifc is None:
             raise DockerError(
diff --git a/gns3server/compute/dynamips/nodes/router.py b/gns3server/compute/dynamips/nodes/router.py
index 2eedfc2c4..8aabf6ddd 100644
--- a/gns3server/compute/dynamips/nodes/router.py
+++ b/gns3server/compute/dynamips/nodes/router.py
@@ -97,7 +97,7 @@ class Router(BaseNode):
         try:
             os.makedirs(os.path.join(self._working_directory, "configs"), exist_ok=True)
         except OSError as e:
-            raise DynamipsError(f"Can't create the dynamips config directory: {str(e)}")
+            raise DynamipsError(f"Can't create the dynamips config directory: {e!s}")
         if dynamips_id:
             self._convert_before_2_0_0_b3(dynamips_id)
 
@@ -153,7 +153,7 @@ class Router(BaseNode):
                 try:
                     shutil.move(path, dst)
                 except OSError as e:
-                    log.error(f"Can't move {path}: {str(e)}")
+                    log.error(f"Can't move {path}: {e!s}")
                     continue
         for path in glob.glob(os.path.join(glob.escape(dynamips_dir), f"*_i{dynamips_id}_*")):
             dst = os.path.join(self._working_directory, os.path.basename(path))
@@ -161,7 +161,7 @@ class Router(BaseNode):
                 try:
                     shutil.move(path, dst)
                 except OSError as e:
-                    log.error(f"Can't move {path}: {str(e)}")
+                    log.error(f"Can't move {path}: {e!s}")
                     continue
 
     def asdict(self):
@@ -1608,7 +1608,7 @@ class Router(BaseNode):
         try:
             open(output_file, "w+").close()
         except OSError as e:
-            raise DynamipsError(f'Can not write capture to "{output_file}": {str(e)}')
+            raise DynamipsError(f'Can not write capture to "{output_file}": {e!s}')
 
         try:
             adapter = self._slots[slot_number]
diff --git a/gns3server/controller/gns3vm/__init__.py b/gns3server/controller/gns3vm/__init__.py
index 0c3c95122..a20a1e81d 100644
--- a/gns3server/controller/gns3vm/__init__.py
+++ b/gns3server/controller/gns3vm/__init__.py
@@ -334,7 +334,7 @@ class GNS3VM:
                 await engine.start()
             except Exception as e:
                 await self._controller.delete_compute("vm")
-                log.error(f"Cannot start the GNS3 VM: {str(e)}")
+                log.error(f"Cannot start the GNS3 VM: {e!s}")
                 await compute.update(name=f"GNS3 VM ({engine.vmname})")
                 compute.set_last_error(str(e))
                 raise e
diff --git a/gns3server/controller/gns3vm/virtualbox_gns3_vm.py b/gns3server/controller/gns3vm/virtualbox_gns3_vm.py
index f3a78f03d..5fe733cd5 100644
--- a/gns3server/controller/gns3vm/virtualbox_gns3_vm.py
+++ b/gns3server/controller/gns3vm/virtualbox_gns3_vm.py
@@ -260,7 +260,7 @@ class VirtualBoxGNS3VM(BaseGNS3VM):
             await self._check_requirements()
             return await self._virtualbox_manager.list_vms()
         except VirtualBoxError as e:
-            raise GNS3VMError(f"Could not list VirtualBox VMs: {str(e)}")
+            raise GNS3VMError(f"Could not list VirtualBox VMs: {e!s}")
 
     async def start(self):
         """
diff --git a/gns3server/controller/gns3vm/vmware_gns3_vm.py b/gns3server/controller/gns3vm/vmware_gns3_vm.py
index 5062d8dc9..b19c85ad9 100644
--- a/gns3server/controller/gns3vm/vmware_gns3_vm.py
+++ b/gns3server/controller/gns3vm/vmware_gns3_vm.py
@@ -116,7 +116,7 @@ class VMwareGNS3VM(BaseGNS3VM):
         try:
             return await self._vmware_manager.list_vms()
         except VMwareError as e:
-            raise GNS3VMError(f"Could not list VMware VMs: {str(e)}")
+            raise GNS3VMError(f"Could not list VMware VMs: {e!s}")
 
     async def start(self):
         """
@@ -143,7 +143,7 @@ class VMwareGNS3VM(BaseGNS3VM):
         try:
             running = await self._is_running()
         except VMwareError as e:
-            raise GNS3VMError(f"Could not list VMware VMs: {str(e)}")
+            raise GNS3VMError(f"Could not list VMware VMs: {e!s}")
         if not running:
             # set the number of vCPUs and amount of RAM
             if self.allocate_vcpus_ram:
@@ -197,7 +197,7 @@ class VMwareGNS3VM(BaseGNS3VM):
         try:
             await self._execute("suspend", [self._vmx_path])
         except GNS3VMError as e:
-            log.warning(f"Error when suspending the VM: {str(e)}")
+            log.warning(f"Error when suspending the VM: {e!s}")
         log.info("GNS3 VM has been suspended")
         self.running = False
 
@@ -211,6 +211,6 @@ class VMwareGNS3VM(BaseGNS3VM):
         try:
             await self._execute("stop", [self._vmx_path, "soft"])
         except GNS3VMError as e:
-            log.warning(f"Error when stopping the VM: {str(e)}")
+            log.warning(f"Error when stopping the VM: {e!s}")
         log.info("GNS3 VM has been stopped")
         self.running = False
diff --git a/gns3server/controller/link.py b/gns3server/controller/link.py
index 2a7ec02d8..c2ef20f7a 100644
--- a/gns3server/controller/link.py
+++ b/gns3server/controller/link.py
@@ -222,7 +222,7 @@ class Link:
         try:
             validate_all_filters(new_filters)
         except FilterValidationError as e:
-            raise ControllerError(f"Invalid packet filter parameters: {str(e)}")
+            raise ControllerError(f"Invalid packet filter parameters: {e!s}")
 
         if new_filters != self.filters:
             self._filters = new_filters
@@ -483,7 +483,7 @@ class Link:
             # Re-raise ControllerError to return error to client
             raise
         except Exception as e:
-            error_msg = f"Error starting Web Wireshark: {str(e)}"
+            error_msg = f"Error starting Web Wireshark: {e!s}"
             log.error(error_msg)
             raise ControllerError(error_msg)
         finally:
@@ -532,7 +532,7 @@ class Link:
         except ControllerError:
             raise
         except Exception as e:
-            error_msg = f"Error restarting Web Wireshark: {str(e)}"
+            error_msg = f"Error restarting Web Wireshark: {e!s}"
             log.error(error_msg)
             raise ControllerError(error_msg)
         finally:
diff --git a/gns3server/controller/node.py b/gns3server/controller/node.py
index dac44f60d..6fb64045f 100644
--- a/gns3server/controller/node.py
+++ b/gns3server/controller/node.py
@@ -1050,7 +1050,7 @@ class Node:
             with open(image, "rb") as f:
                 await self._compute.post(f"/{self._node_type}/images/{os.path.basename(img)}", data=f, timeout=None)
         except OSError as e:
-            raise ControllerError(f"Can't upload {image}: {str(e)}")
+            raise ControllerError(f"Can't upload {image}: {e!s}")
         self.project.emit_notification("log.info", {"message": f"Upload finished for {img}"})
         return True
 
diff --git a/gns3server/controller/ports/port_factory.py b/gns3server/controller/ports/port_factory.py
index c17434578..0568ef788 100644
--- a/gns3server/controller/ports/port_factory.py
+++ b/gns3server/controller/ports/port_factory.py
@@ -88,7 +88,7 @@ class StandardPortFactory:
                             **cls._generate_replacement(interface_number, segment_number),
                         )
                     except (IndexError, ValueError, KeyError) as e:
-                        raise ControllerError(f"Invalid port name format {port_name_format}: {str(e)}")
+                        raise ControllerError(f"Invalid port name format {port_name_format}: {e!s}")
 
                     port_name = custom_adapter_settings.get("port_name", port_name)
                     port = PortFactory(port_name, segment_number, adapter_number, port_number, "ethernet")
diff --git a/gns3server/controller/project.py b/gns3server/controller/project.py
index ad42e9323..83b95b41f 100644
--- a/gns3server/controller/project.py
+++ b/gns3server/controller/project.py
@@ -1731,7 +1731,7 @@ class Project:
                 )
             shutil.rmtree(self.path)
         except OSError as e:
-            raise ControllerError(f"Cannot delete project directory {self.path}: {str(e)}")
+            raise ControllerError(f"Cannot delete project directory {self.path}: {e!s}")
         self.emit_controller_notification("project.deleted", self.asdict())
 
     def _get_disconnected_computes(self):
@@ -2081,7 +2081,7 @@ class Project:
             else:
                 log.info("Fast duplication failed, fallback to normal duplication")
         except Exception as e:
-            raise ControllerError(f"Cannot duplicate project: {str(e)}")
+            raise ControllerError(f"Cannot duplicate project: {e!s}")
 
         try:
             begin = time.time()
@@ -2119,7 +2119,7 @@ class Project:
 
             log.info(f"Project '{project.name}' duplicated in {time.time() - begin:.4f} seconds")
         except (ValueError, OSError, UnicodeEncodeError) as e:
-            raise ControllerError(f"Cannot duplicate project: {str(e)}")
+            raise ControllerError(f"Cannot duplicate project: {e!s}")
 
         if previous_status == "closed":
             await self.close()
diff --git a/gns3server/controller/topology.py b/gns3server/controller/topology.py
index f2390930a..1e5dd3810 100644
--- a/gns3server/controller/topology.py
+++ b/gns3server/controller/topology.py
@@ -139,7 +139,7 @@ def load_topology(path):
         with open(path, encoding="utf-8") as f:
             topo = json.load(f)
     except (OSError, UnicodeDecodeError, ValueError) as e:
-        raise ControllerError(f"Could not load topology {path}: {str(e)}")
+        raise ControllerError(f"Could not load topology {path}: {e!s}")
 
     if topo.get("revision", 0) > GNS3_FILE_FORMAT_REVISION:
         raise ControllerError(
@@ -154,7 +154,7 @@ def load_topology(path):
         try:
             shutil.copy(path, path + ".backup{}".format(topo.get("revision", 0)))
         except OSError as e:
-            raise ControllerError(f"Can't write backup of the topology {path}: {str(e)}")
+            raise ControllerError(f"Can't write backup of the topology {path}: {e!s}")
         changed = True
         # update the version because we converted the topology
         topo["version"] = __version__
@@ -210,7 +210,7 @@ def load_topology(path):
             with open(path, "w+", encoding="utf-8") as f:
                 json.dump(topo, f, indent=4, sort_keys=True)
         except OSError as e:
-            raise ControllerError(f"Can't write the topology {path}: {str(e)}")
+            raise ControllerError(f"Can't write the topology {path}: {e!s}")
     return topo
 
 
@@ -326,7 +326,7 @@ def _convert_2_0_0_beta_2(topo, topo_path):
                 for path in glob.glob(os.path.join(glob.escape(dynamips_dir), "configs", f"i{dynamips_id}_*")):
                     shutil.move(path, os.path.join(node_dir, "configs", os.path.basename(path)))
             except OSError as e:
-                raise ControllerError(f"Can't convert project {topo_path}: {str(e)}")
+                raise ControllerError(f"Can't convert project {topo_path}: {e!s}")
     return topo
 
 
diff --git a/gns3server/utils/images.py b/gns3server/utils/images.py
index 06b4ae9be..60d61ddc0 100644
--- a/gns3server/utils/images.py
+++ b/gns3server/utils/images.py
@@ -114,7 +114,7 @@ async def list_images(image_type):
                         }
                     )
                 except OSError as e:
-                    log.warning(f"Can't add image {path}: {str(e)}")
+                    log.warning(f"Can't add image {path}: {e!s}")
     return images
 
 
diff --git a/gns3server/utils/packet_filter_validation.py b/gns3server/utils/packet_filter_validation.py
index 1b9481ffd..d20ac9f24 100644
--- a/gns3server/utils/packet_filter_validation.py
+++ b/gns3server/utils/packet_filter_validation.py
@@ -62,7 +62,7 @@ def validate_bpf_syntax(bpf_expression: str) -> Dict[str, Any]:
 
     except Exception as e:
         log.error("Unexpected error during BPF validation: %s", e)
-        return {"valid": False, "error": f"BPF validation error: {str(e)}"}
+        return {"valid": False, "error": f"BPF validation error: {e!s}"}
 
 
 def validate_filter_parameters(filter_type: str, values: List[Any]) -> None:
diff --git a/tests/stress/benchmark_running_server.py b/tests/stress/benchmark_running_server.py
index 6400aebe1..234372100 100644
--- a/tests/stress/benchmark_running_server.py
+++ b/tests/stress/benchmark_running_server.py
@@ -134,7 +134,7 @@ async def benchmark_get_projects(base_url, headers, project_count, iterations=10
                 else:
                     print(f"  Iteration {i + 1}: ERROR {response.status_code}")
             except Exception as e:
-                print(f"  Iteration {i + 1}: Exception - {type(e).__name__}: {str(e)}")
+                print(f"  Iteration {i + 1}: Exception - {type(e).__name__}: {e!s}")
 
     # Cleanup test projects
     if project_count > 0: