diff --git a/.github/workflows/python-sanity.yml b/.github/workflows/python-sanity.yml
index 3de7b03..d5313d6 100644
--- a/.github/workflows/python-sanity.yml
+++ b/.github/workflows/python-sanity.yml
@@ -37,3 +37,6 @@ jobs:
 
       - name: pylint
         run: python3 -m pylint --enable=E nvmet/ nvmetcli
+
+      - name: mypy
+        run: python3 -m mypy
diff --git a/nvmet/__init__.py b/nvmet/__init__.py
index 7566dbd..4380c17 100644
--- a/nvmet/__init__.py
+++ b/nvmet/__init__.py
@@ -1,5 +1,10 @@
 """
 NVMe-oF Target configfs-based kernel driver API
 """
-from .nvme import (ANAGroup, DEFAULT_SAVE_FILE, Host, Namespace,  # noqa: F401
-                   Passthru, Port, Referral, Root, Subsystem, CFSError)
+from .nvme import (ANAGroup, CFSError, CFSNode, DEFAULT_SAVE_FILE, Host,
+                   Namespace, Passthru, Port, Referral, Root, Subsystem)
+
+__all__ = [
+    'ANAGroup', 'CFSError', 'CFSNode', 'DEFAULT_SAVE_FILE', 'Host',
+    'Namespace', 'Passthru', 'Port', 'Referral', 'Root', 'Subsystem',
+]
diff --git a/nvmet/nvme.py b/nvmet/nvme.py
index ecd26af..5397a00 100644
--- a/nvmet/nvme.py
+++ b/nvmet/nvme.py
@@ -18,6 +18,8 @@
 under the License.
 '''
 
+from __future__ import annotations
+
 import os
 import stat
 import uuid
@@ -26,9 +28,12 @@
 import shlex
 from doctest import testmod
 from glob import iglob as glob
+from typing import Any, Callable, Iterator
 
 DEFAULT_SAVE_FILE = '/etc/nvmet/config.json'
 
+ErrFunc = Callable[[str], None]
+
 
 class CFSError(Exception):
     '''
@@ -54,30 +59,34 @@ class CFSNode:
 
     configfs_dir = '/sys/kernel/config/nvmet'
 
-    def __init__(self):
-        self._path = self.configfs_dir
-        self._enable = None
-        self.attr_groups = []
+    def __init__(self) -> None:
+        self._path: str = self.configfs_dir
+        self._enable: int | None = None
+        self.attr_groups: list[str] = []
 
-    def __eq__(self, other):
+    def __eq__(self, other: object) -> bool:
         '''
         Checks if two CFSNode objects are equal.
         '''
+        if not isinstance(other, CFSNode):
+            return NotImplemented
         return self._path == other._path
 
-    def __ne__(self, other):
+    def __ne__(self, other: object) -> bool:
         '''
         Checks if two CFSNode objects are not equal.
         '''
+        if not isinstance(other, CFSNode):
+            return NotImplemented
         return self._path != other._path
 
-    def _get_path(self):
+    def _get_path(self) -> str:
         '''
         Returns the path of the CFSNode.
         '''
         return self._path
 
-    def _create_in_cfs(self, mode):
+    def _create_in_cfs(self, mode: str) -> None:
         '''
         Creates the configFS node if it does not already exist, depending on
         the mode.
@@ -102,13 +111,13 @@ def _create_in_cfs(self, mode):
                                f" in configFS") from exc
         self.get_enable()
 
-    def _exists(self):
+    def _exists(self) -> bool:
         '''
         Returns True if the CFSNode exists, False otherwise.
         '''
         return os.path.isdir(self.path)
 
-    def _check_self(self):
+    def _check_self(self) -> None:
         '''
         Checks if the CFSNode exists.
         '''
@@ -116,7 +125,7 @@ def _check_self(self):
             raise CFSNotFound(f"This {self.__class__.__name__} does not "
                               f"exist in configFS")
 
-    def list_attrs(self, group, writable=None):
+    def list_attrs(self, group: str, writable: bool | None = None) -> list[str]:
         '''
         @param group: The attribute group
         @param writable: If None (default), returns all attributes, if True,
@@ -141,14 +150,14 @@ def list_attrs(self, group, writable=None):
         names.sort()
         return names
 
-    def _attr_is_writable(self, group, name):
+    def _attr_is_writable(self, group: str, name: str) -> int:
         '''
         Returns True if the attribute is writable, False otherwise.
         '''
         s = os.stat(f"{self._path}/{group}_{name}")
         return s[stat.ST_MODE] & stat.S_IWUSR
 
-    def set_attr(self, group, attribute, value):
+    def set_attr(self, group: str, attribute: str, value: Any) -> None:
         '''
         Sets the value of a named attribute.
         The attribute must exist in configFS.
@@ -173,7 +182,7 @@ def set_attr(self, group, attribute, value):
         except OSError as e:
             raise CFSError(f"Cannot set attribute {path}: {e}") from e
 
-    def get_attr(self, group, attribute):
+    def get_attr(self, group: str, attribute: str) -> str:
         '''
         Gets the value of a named attribute.
         @param group: The attribute group
@@ -188,7 +197,7 @@ def get_attr(self, group, attribute):
         with open(path, 'r', encoding="utf-8") as file_fd:
             return file_fd.read().strip()
 
-    def get_enable(self):
+    def get_enable(self) -> int | None:
         '''
         Returns the value of the 'enable' attribute.
         '''
@@ -201,7 +210,7 @@ def get_enable(self):
             self._enable = int(file_fd.read().strip())
         return self._enable
 
-    def set_enable(self, value):
+    def set_enable(self, value: Any) -> None:
         '''
         Sets the value of the 'enable' attribute.
         '''
@@ -218,7 +227,7 @@ def set_enable(self, value):
             raise CFSError(f"Cannot enable {self.path}: {e} ({value})") from e
         self._enable = value
 
-    def delete(self):
+    def delete(self) -> None:
         '''
         If the underlying configFS object does not exist, this method does
         nothing. If the underlying configFS object exists, this method attempts
@@ -235,11 +244,11 @@ def delete(self):
                       + " deleted either by calling the delete() method, or by"
                       + " any other means, it will be False.")
 
-    def dump(self):
+    def dump(self) -> dict[str, Any]:
         '''
         Returns a dict with the config of the object.
         '''
-        d = {}
+        d: dict[str, Any] = {}
         for group in self.attr_groups:
             a = {}
             for i in self.list_attrs(group, writable=True):
@@ -249,7 +258,8 @@ def dump(self):
             d['enable'] = self._enable
         return d
 
-    def _setup_attrs(self, attr_dict, err_func):
+    def _setup_attrs(self, attr_dict: dict[str, Any],
+                     err_func: ErrFunc) -> None:
         '''
         Set up attributes from a dict.
         '''
@@ -268,7 +278,7 @@ class Root(CFSNode):
     '''
     The root of the NVMe target configfs hierarchy.
     '''
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
 
         self.attr_groups = ['discovery']
@@ -281,7 +291,7 @@ def __init__(self):
         self._path = self.configfs_dir
         self._create_in_cfs('lookup')
 
-    def _modprobe(self, modname):
+    def _modprobe(self, modname: str) -> None:
         '''
         Load a kernel module.
         '''
@@ -298,7 +308,7 @@ def _modprobe(self, modname):
         except OSError:
             pass
 
-    def _list_subsystems(self):
+    def _list_subsystems(self) -> Iterator[Subsystem]:
         self._check_self()
 
         for d in os.listdir(f"{self._path}/subsystems/"):
@@ -307,7 +317,7 @@ def _list_subsystems(self):
     subsystems = property(_list_subsystems,
                           doc="Get the list of Subsystems.")
 
-    def _list_ports(self):
+    def _list_ports(self) -> Iterator[Port]:
         self._check_self()
 
         for d in os.listdir(f"{self._path}/ports/"):
@@ -316,7 +326,7 @@ def _list_ports(self):
     ports = property(_list_ports,
                      doc="Get the list of Ports.")
 
-    def _list_hosts(self):
+    def _list_hosts(self) -> Iterator[Host]:
         self._check_self()
 
         for h in os.listdir(f"{self._path}/hosts/"):
@@ -325,7 +335,7 @@ def _list_hosts(self):
     hosts = property(_list_hosts,
                      doc="Get the list of Hosts.")
 
-    def save_to_file(self, savefile=None):
+    def save_to_file(self, savefile: str | None = None) -> None:
         '''
         Write the configuration in json format to a file.
         '''
@@ -357,7 +367,7 @@ def save_to_file(self, savefile=None):
             if dir_fd:
                 os.close(dir_fd)
 
-    def clear_existing(self):
+    def clear_existing(self) -> None:
         '''
         Remove entire current configuration.
         '''
@@ -369,7 +379,8 @@ def clear_existing(self):
         for h in self.hosts:
             h.delete()
 
-    def restore(self, config, clear_existing=False, abort_on_error=False):
+    def restore(self, config: dict[str, Any], clear_existing: bool = False,
+                abort_on_error: bool = False) -> list[str]:
         '''
         Takes a dict generated by dump() and reconfigures the target to match.
         Returns list of non-fatal errors that were encountered.
@@ -382,13 +393,14 @@ def restore(self, config, clear_existing=False, abort_on_error=False):
             if any(self.subsystems):
                 raise CFSError("subsystems present, not restoring")
 
-        errors = []
+        errors: list[str] = []
 
+        err_func: ErrFunc
         if abort_on_error:
-            def err_func(err_str):
+            def err_func(err_str: str) -> None:
                 raise CFSError(err_str)
         else:
-            def err_func(err_str):
+            def err_func(err_str: str) -> None:
                 errors.append(err_str + ", skipped")
 
         # Create the hosts first because the subsystems reference them
@@ -415,8 +427,9 @@ def err_func(err_str):
 
         return errors
 
-    def restore_from_file(self, savefile=None, clear_existing=True,
-                          abort_on_error=False):
+    def restore_from_file(self, savefile: str | None = None,
+                          clear_existing: bool = True,
+                          abort_on_error: bool = False) -> list[str]:
         '''
         Restore the configuration from a file in json format.
         Returns a list of non-fatal errors. If abort_on_error is set,
@@ -432,7 +445,7 @@ def restore_from_file(self, savefile=None, clear_existing=True,
             return self.restore(config, clear_existing=clear_existing,
                                 abort_on_error=abort_on_error)
 
-    def dump(self):
+    def dump(self) -> dict[str, Any]:
         d = super().dump()
         d['subsystems'] = [s.dump() for s in self.subsystems]
         d['ports'] = [p.dump() for p in self.ports]
@@ -446,10 +459,10 @@ class Subsystem(CFSNode):
     A Subsystem is identified by its NQN.
     '''
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return f"<Subsystem {self.nqn}>"
 
-    def __init__(self, nqn=None, mode='any'):
+    def __init__(self, nqn: str | None = None, mode: str = 'any') -> None:
         '''
         @param nqn: The Subsystems' NQN.
             If no NQN is specified, one will be generated.
@@ -474,7 +487,7 @@ def __init__(self, nqn=None, mode='any'):
         self._path = f"{self.configfs_dir}/subsystems/{nqn}"
         self._create_in_cfs(mode)
 
-    def _generate_nqn(self):
+    def _generate_nqn(self) -> str:
         '''
         Generates a new NQN.
         '''
@@ -482,7 +495,7 @@ def _generate_nqn(self):
         name = str(uuid.uuid4())
         return f"{prefix}:{name}"
 
-    def delete(self):
+    def delete(self) -> None:
         '''
         Recursively deletes a Subsystem object.
         This will delete all attached Namespace objects and then the
@@ -495,7 +508,7 @@ def delete(self):
             self.remove_allowed_host(h)
         super().delete()
 
-    def _list_namespaces(self):
+    def _list_namespaces(self) -> Iterator[Namespace]:
         '''
         Lists the namespaces of the subsystem.
         '''
@@ -506,7 +519,7 @@ def _list_namespaces(self):
     namespaces = property(_list_namespaces,
                           doc="Get the list of Namespaces for the Subsystem.")
 
-    def _get_passthru(self):
+    def _get_passthru(self) -> Passthru:
         '''
         Returns the passthru object of the subsystem.
         '''
@@ -516,7 +529,7 @@ def _get_passthru(self):
     passthru = property(_get_passthru,
                         doc="Get the passthru node for the subsystem")
 
-    def _list_allowed_hosts(self):
+    def _list_allowed_hosts(self) -> list[str]:
         '''
         Lists the allowed hosts of the subsystem.
         '''
@@ -527,7 +540,7 @@ def _list_allowed_hosts(self):
                              doc="Get the list of Allowed Hosts for the "
                              + "Subsystem.")
 
-    def add_allowed_host(self, nqn):
+    def add_allowed_host(self, nqn: str) -> None:
         '''
         Enable access for the host identified by I{nqn} to the Subsystem
         '''
@@ -537,7 +550,7 @@ def add_allowed_host(self, nqn):
         except OSError as e:
             raise CFSError(f"Could not symlink {nqn} in configFS: {e}") from e
 
-    def remove_allowed_host(self, nqn):
+    def remove_allowed_host(self, nqn: str) -> None:
         '''
         Disable access for the host identified by I{nqn} to the Subsystem
         '''
@@ -546,14 +559,14 @@ def remove_allowed_host(self, nqn):
         except OSError as e:
             raise CFSError(f"Could not unlink {nqn} in configFS: {e}") from e
 
-    def has_passthru(self):
+    def has_passthru(self) -> bool:
         '''
         Check if the subsystem has a passthru node.
         '''
         return os.path.isdir(os.path.join(self.path, "passthru"))
 
     @classmethod
-    def setup(cls, t, err_func):
+    def setup(cls, t: dict[str, Any], err_func: ErrFunc) -> None:
         '''
         Set up Subsystem objects based upon t dict, from saved config.
         Guard against missing or bad dict items, but keep going.
@@ -579,7 +592,7 @@ def setup(cls, t, err_func):
 
         s._setup_attrs(t, err_func)
 
-    def dump(self):
+    def dump(self) -> dict[str, Any]:
         d = super().dump()
         d['nqn'] = self.nqn
         d['namespaces'] = [ns.dump() for ns in self.namespaces]
@@ -597,10 +610,11 @@ class Namespace(CFSNode):
 
     MAX_NSID = 8192
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return f"<Namespace {self.nsid}>"
 
-    def __init__(self, subsystem, nsid=None, mode='any'):
+    def __init__(self, subsystem: Subsystem, nsid: int | None = None,
+                 mode: str = 'any') -> None:
         '''
         @param subsystem: The parent Subsystem object
         @param nsid: The Namespace identifier
@@ -641,19 +655,19 @@ def __init__(self, subsystem, nsid=None, mode='any'):
         self._path = f"{self.subsystem.path}/namespaces/{self.nsid}"
         self._create_in_cfs(mode)
 
-    def _get_subsystem(self):
+    def _get_subsystem(self) -> Subsystem:
         '''
         Returns the parent subsystem.
         '''
         return self._subsystem
 
-    def _get_nsid(self):
+    def _get_nsid(self) -> int:
         '''
         Returns the namespace ID.
         '''
         return self._nsid
 
-    def _get_grpid(self):
+    def _get_grpid(self) -> int:
         '''
         Returns the ANA group ID.
         '''
@@ -665,7 +679,7 @@ def _get_grpid(self):
                 _grpid = int(file_fd.read().strip())
         return _grpid
 
-    def set_grpid(self, grpid):
+    def set_grpid(self, grpid: Any) -> None:
         '''
         Sets the ANA group ID.
         '''
@@ -682,7 +696,8 @@ def set_grpid(self, grpid):
     nsid = property(_get_nsid, doc="Get the NSID as an int.")
 
     @classmethod
-    def setup(cls, subsys, n, err_func):
+    def setup(cls, subsys: Subsystem, n: dict[str, Any],
+              err_func: ErrFunc) -> None:
         '''
         Set up a Namespace object based upon n dict, from saved config.
         Guard against missing or bad dict items, but keep going.
@@ -703,7 +718,7 @@ def setup(cls, subsys, n, err_func):
         if 'ana_grpid' in n:
             ns.set_grpid(int(n['ana_grpid']))
 
-    def dump(self):
+    def dump(self) -> dict[str, Any]:
         '''
         Returns a dict with the config of the object.
         '''
@@ -719,7 +734,7 @@ class Passthru(CFSNode):
     A Passthru is identified by its parent Subsystem.
     '''
 
-    def __init__(self, subsystem):
+    def __init__(self, subsystem: Subsystem) -> None:
         '''
         @param subsystem: The parent Subsystem object.
         @return: A Passthru object.
@@ -728,7 +743,7 @@ def __init__(self, subsystem):
         self._path = f"{subsystem.path}/passthru"
         self.attr_groups = ['device']
 
-    def _get_clear_ids(self):
+    def _get_clear_ids(self) -> int:
         '''
         Get the passthru namespace clear_ids attribute.
         '''
@@ -743,7 +758,7 @@ def _get_clear_ids(self):
     ids = property(_get_clear_ids,
                    doc="Get the passthru namespace clear_ids attribute.")
 
-    def set_clear_ids(self, clear):
+    def set_clear_ids(self, clear: Any) -> None:
         '''
         Set the passthru namespace clear_ids attribute.
         '''
@@ -753,7 +768,7 @@ def set_clear_ids(self, clear):
             with open(path, 'w', encoding="utf-8") as file_fd:
                 file_fd.write(str(clear))
 
-    def _get_admin_timeout(self):
+    def _get_admin_timeout(self) -> int:
         '''
         Get the passthru admin command timeout.
         '''
@@ -768,7 +783,7 @@ def _get_admin_timeout(self):
     admin_timeout = property(_get_admin_timeout,
                              doc="Get the passthru admin command timeout.")
 
-    def set_admin_timeout(self, timeout):
+    def set_admin_timeout(self, timeout: Any) -> None:
         '''
         Set the passthru admin command timeout.
         '''
@@ -778,7 +793,7 @@ def set_admin_timeout(self, timeout):
             with open(path, 'w', encoding="utf-8") as file_fd:
                 file_fd.write(str(timeout))
 
-    def _get_io_timeout(self):
+    def _get_io_timeout(self) -> int:
         '''
         Get the passthru IO command timeout.
         '''
@@ -793,7 +808,7 @@ def _get_io_timeout(self):
     io_timeout = property(_get_io_timeout,
                           doc="Get the passthru IO command timeout.")
 
-    def set_io_timeout(self, timeout):
+    def set_io_timeout(self, timeout: Any) -> None:
         '''
         Set the passthru IO command timeout.
         '''
@@ -804,7 +819,8 @@ def set_io_timeout(self, timeout):
                 file_fd.write(str(timeout))
 
     @classmethod
-    def setup(cls, subsys, p, err_func):
+    def setup(cls, subsys: Subsystem, p: dict[str, Any],
+              err_func: ErrFunc) -> None:
         '''
         Set up a Passthru object based upon p dict, from saved config.
         '''
@@ -821,7 +837,7 @@ def setup(cls, subsys, p, err_func):
         if 'io_timeout' in p:
             pt.set_io_timeout(int(p['io_timeout']))
 
-    def dump(self):
+    def dump(self) -> dict[str, Any]:
         '''
         Returns a dict with the config of the object.
         '''
@@ -839,10 +855,10 @@ class Port(CFSNode):
 
     MAX_PORTID = 8192
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return f"<Port {self.portid}>"
 
-    def __init__(self, portid, mode='any'):
+    def __init__(self, portid: Any, mode: str = 'any') -> None:
         super().__init__()
 
         self.attr_groups = ['addr', 'param']
@@ -850,7 +866,7 @@ def __init__(self, portid, mode='any'):
         self._path = f"{self.configfs_dir}/ports/{self._portid}"
         self._create_in_cfs(mode)
 
-    def _get_portid(self):
+    def _get_portid(self) -> int:
         '''
         Returns the port ID.
         '''
@@ -858,7 +874,7 @@ def _get_portid(self):
 
     portid = property(_get_portid, doc="Get the Port ID as an int.")
 
-    def _list_subsystems(self):
+    def _list_subsystems(self) -> list[str]:
         '''
         Lists the subsystems of the port.
         '''
@@ -868,7 +884,7 @@ def _list_subsystems(self):
     subsystems = property(_list_subsystems,
                           doc="Get the list of Subsystem for this Port.")
 
-    def add_subsystem(self, nqn):
+    def add_subsystem(self, nqn: str) -> None:
         '''
         Enable access to the Subsystem identified by I{nqn} through this Port.
         '''
@@ -878,7 +894,7 @@ def add_subsystem(self, nqn):
         except OSError as e:
             raise CFSError(f"Could not symlink {nqn} in configFS: {e}") from e
 
-    def remove_subsystem(self, nqn):
+    def remove_subsystem(self, nqn: str) -> None:
         '''
         Disable access to the Subsystem identified by I{nqn} through this Port.
         '''
@@ -887,7 +903,7 @@ def remove_subsystem(self, nqn):
         except OSError as e:
             raise CFSError(f"Could not unlink {nqn} in configFS: {e}") from e
 
-    def delete(self):
+    def delete(self) -> None:
         '''
         Recursively deletes a Port object.
         '''
@@ -900,7 +916,7 @@ def delete(self):
             r.delete()
         super().delete()
 
-    def _list_referrals(self):
+    def _list_referrals(self) -> Iterator[Referral]:
         '''
         Lists the referrals of the port.
         '''
@@ -911,7 +927,7 @@ def _list_referrals(self):
     referrals = property(_list_referrals,
                          doc="Get the list of Referrals for this Port.")
 
-    def _list_ana_groups(self):
+    def _list_ana_groups(self) -> Iterator[ANAGroup]:
         '''
         Lists the ANA groups of the port.
         '''
@@ -924,7 +940,7 @@ def _list_ana_groups(self):
                           doc="Get the list of ANA Groups for this Port.")
 
     @classmethod
-    def setup(cls, n, err_func):
+    def setup(cls, n: dict[str, Any], err_func: ErrFunc) -> None:
         '''
         Set up a Port object based upon n dict, from saved config.
         Guard against missing or bad dict items, but keep going.
@@ -949,7 +965,7 @@ def setup(cls, n, err_func):
         for r in n.get('referrals', []):
             Referral.setup(port, r, err_func)
 
-    def dump(self):
+    def dump(self) -> dict[str, Any]:
         '''
         Returns a dict with the config of the object.
         '''
@@ -966,10 +982,10 @@ class Referral(CFSNode):
     This is an interface to a NVMe Referral in configFS.
     '''
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return f"<Referral {self.name}>"
 
-    def __init__(self, port, name, mode='any'):
+    def __init__(self, port: Port, name: str, mode: str = 'any') -> None:
         super().__init__()
 
         if not isinstance(port, Port):
@@ -981,7 +997,7 @@ def __init__(self, port, name, mode='any'):
         self._path = f"{self.port.path}/referrals/{self._name}"
         self._create_in_cfs(mode)
 
-    def _get_name(self):
+    def _get_name(self) -> str:
         '''
         Returns the name of the referral.
         '''
@@ -990,7 +1006,7 @@ def _get_name(self):
     name = property(_get_name, doc="Get the Referral name.")
 
     @classmethod
-    def setup(cls, port, n, err_func):
+    def setup(cls, port: Port, n: dict[str, Any], err_func: ErrFunc) -> None:
         '''
         Set up a Referral based upon n dict, from saved config.
         Guard against missing or bad dict items, but keep going.
@@ -1009,7 +1025,7 @@ def setup(cls, port, n, err_func):
 
         r._setup_attrs(n, err_func)
 
-    def dump(self):
+    def dump(self) -> dict[str, Any]:
         '''
         Returns a dict with the config of the object.
         '''
@@ -1025,10 +1041,11 @@ class ANAGroup(CFSNode):
 
     MAX_GRPID = 1024
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return f"<ANA Group {self.grpid}>"
 
-    def __init__(self, port, grpid, mode='any'):
+    def __init__(self, port: Port, grpid: int | None,
+                 mode: str = 'any') -> None:
         super().__init__()
 
         if not os.path.isdir(f"{port.path}/ana_groups"):
@@ -1056,7 +1073,7 @@ def __init__(self, port, grpid, mode='any'):
         self._path = f"{self._port.path}/ana_groups/{self.grpid}"
         self._create_in_cfs(mode)
 
-    def _get_grpid(self):
+    def _get_grpid(self) -> int:
         '''
         Returns the ANA group ID.
         '''
@@ -1065,7 +1082,7 @@ def _get_grpid(self):
     grpid = property(_get_grpid, doc="Get the ANA Group ID.")
 
     @classmethod
-    def setup(cls, port, n, err_func):
+    def setup(cls, port: Port, n: dict[str, Any], err_func: ErrFunc) -> None:
         '''
         Set up an ANA Group object based upon n dict, from saved config.
         Guard against missing or bad dict items, but keep going.
@@ -1084,7 +1101,7 @@ def setup(cls, port, n, err_func):
 
         a._setup_attrs(n, err_func)
 
-    def delete(self):
+    def delete(self) -> None:
         '''
         Deletes the ANA group.
         '''
@@ -1092,7 +1109,7 @@ def delete(self):
         if self.grpid != 1:
             super().delete()
 
-    def dump(self):
+    def dump(self) -> dict[str, Any]:
         '''
         Returns a dict with the config of the object.
         '''
@@ -1107,10 +1124,10 @@ class Host(CFSNode):
     A Host is identified by its NQN.
     '''
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return f"<Host {self.nqn}>"
 
-    def __init__(self, nqn, mode='any'):
+    def __init__(self, nqn: str, mode: str = 'any') -> None:
         '''
         @param nqn: The Hosts's NQN.
         @type nqn: string
@@ -1130,7 +1147,7 @@ def __init__(self, nqn, mode='any'):
         self._create_in_cfs(mode)
 
     @classmethod
-    def setup(cls, t, err_func):
+    def setup(cls, t: dict[str, Any], err_func: ErrFunc) -> None:
         '''
         Set up Host objects based upon t dict, from saved config.
         Guard against missing or bad dict items, but keep going.
@@ -1149,7 +1166,7 @@ def setup(cls, t, err_func):
 
         h._setup_attrs(t, err_func)
 
-    def dump(self):
+    def dump(self) -> dict[str, Any]:
         '''
         Returns a dict with the config of the object.
         '''
@@ -1158,7 +1175,7 @@ def dump(self):
         return d
 
 
-def _test():
+def _test() -> None:
     testmod()
 
 
diff --git a/nvmet/test_nvmet.py b/nvmet/test_nvmet.py
index 7c8900a..7a17410 100644
--- a/nvmet/test_nvmet.py
+++ b/nvmet/test_nvmet.py
@@ -2,6 +2,8 @@
 Tests for the nvmet API.
 """
 
+from __future__ import annotations
+
 import os
 import random
 import stat
@@ -20,7 +22,7 @@
 TEMP_BACKING_FILE_SIZE = 512 * 1024 * 1024
 
 
-def _is_usable_device(path):
+def _is_usable_device(path: str) -> bool:
     '''
     Return True if 'path' is usable as a namespace backing device (a
     block device or a regular file). Any OSError from stat() (missing
@@ -34,7 +36,7 @@ def _is_usable_device(path):
     return stat.S_ISBLK(st.st_mode) or stat.S_ISREG(st.st_mode)
 
 
-def _usable_devices():
+def _usable_devices() -> list[str]:
     '''
     Return the subset of NVMET_TEST_DEVICES that are usable as a
     namespace backing device.
@@ -42,7 +44,7 @@ def _usable_devices():
     return [x for x in NVMET_TEST_DEVICES if _is_usable_device(x)]
 
 
-def _make_temp_backing_file():
+def _make_temp_backing_file() -> str:
     '''
     Create a temporary sparse file suitable for use as a namespace
     backing file, equivalent to 'truncate --size=512M'.
@@ -53,7 +55,7 @@ def _make_temp_backing_file():
     return path
 
 
-def get_test_devices(count, testcase):
+def get_test_devices(count: int, testcase: unittest.TestCase) -> list[str]:
     '''
     Return a list of 'count' backing devices to use for namespaces.
 
@@ -73,7 +75,7 @@ class TestNvmet(unittest.TestCase):
     '''
     Tests for the nvmet API.
     '''
-    def test_subsystem(self):
+    def test_subsystem(self) -> None:
         '''
         Test Subsystem creation and deletion.
         '''
@@ -120,7 +122,7 @@ def test_subsystem(self):
             s.delete()
         self.assertEqual(len(list(root.subsystems)), 0)
 
-    def test_namespace(self):
+    def test_namespace(self) -> None:
         '''
         Test Namespace creation and deletion.
         '''
@@ -174,7 +176,7 @@ def test_namespace(self):
             n.delete()
         self.assertEqual(len(list(s.namespaces)), 0)
 
-    def test_namespace_attrs(self):
+    def test_namespace_attrs(self) -> None:
         '''
         Test Namespace attributes.
         '''
@@ -215,7 +217,7 @@ def test_namespace_attrs(self):
         n.set_enable(1)
         n.delete()
 
-    def test_recursive_delete(self):
+    def test_recursive_delete(self) -> None:
         '''
         Test recursive deletion of a Subsystem.
         '''
@@ -229,7 +231,7 @@ def test_recursive_delete(self):
         s.delete()
         self.assertEqual(len(list(root.subsystems)), 0)
 
-    def test_port(self):
+    def test_port(self) -> None:
         '''
         Test Port creation and deletion.
         '''
@@ -268,7 +270,7 @@ def test_port(self):
             p.delete()
         self.assertEqual(len(list(root.ports)), 0)
 
-    def test_loop_port(self):
+    def test_loop_port(self) -> None:
         '''
         Test loop port functionality.
         '''
@@ -324,7 +326,7 @@ def test_loop_port(self):
         p.add_subsystem('testnqn')
         p.delete()
 
-    def test_host(self):
+    def test_host(self) -> None:
         '''
         Test Host creation and deletion.
         '''
@@ -363,7 +365,7 @@ def test_host(self):
             h.delete()
         self.assertEqual(len(list(root.hosts)), 0)
 
-    def test_referral(self):
+    def test_referral(self) -> None:
         '''
         Test Referral creation and deletion.
         '''
@@ -449,7 +451,7 @@ def test_referral(self):
         r1.delete()
         self.assertEqual(len(list(p.referrals)), 0)
 
-    def test_allowed_hosts(self):
+    def test_allowed_hosts(self) -> None:
         '''
         Test allowed hosts functionality.
         '''
@@ -477,7 +479,7 @@ def test_allowed_hosts(self):
         # invalid removal
         self.assertRaises(nvme.CFSError, s.remove_allowed_host, 'foobar')
 
-    def test_invalid_input(self):
+    def test_invalid_input(self) -> None:
         '''
         Test invalid input to the API.
         '''
@@ -502,7 +504,7 @@ def test_invalid_input(self):
         self.assertRaises(nvme.CFSError, nvme.Port,
                           portid=1 << 17, mode='create')
 
-    def test_save_restore(self):
+    def test_save_restore(self) -> None:
         '''
         Test save and restore functionality.
         '''
diff --git a/nvmetcli b/nvmetcli
index f39e8af..09b908e 100755
--- a/nvmetcli
+++ b/nvmetcli
@@ -18,18 +18,19 @@ License for the specific language governing permissions and limitations
 under the License.
 '''
 
-from __future__ import print_function
+from __future__ import annotations
 
 import os
 import sys
 import errno
 from string import hexdigits
+from typing import Any, Callable
 import uuid
 import configshell
 import nvmet as nvme
 
 
-def nguid_set(nguid):
+def nguid_set(nguid: str) -> bool:
     '''
     Check if the nguid is set.
     '''
@@ -40,7 +41,9 @@ class UINode(configshell.ConfigNode):
     '''
     A node in the UI.
     '''
-    def __init__(self, name, parent=None, cfnode=None, shell=None):
+    def __init__(self, name: str, parent: UINode | None = None,
+                 cfnode: nvme.CFSNode | None = None,
+                 shell: Any = None) -> None:
         configshell.ConfigNode.__init__(self, name, parent, shell)
         self.cfnode = cfnode
         if self.cfnode:
@@ -49,7 +52,8 @@ class UINode(configshell.ConfigNode):
                     self._init_group(group)
         self.refresh()
 
-    def _init_group(self, group):
+    def _init_group(self, group: str) -> None:
+        assert self.cfnode is not None
         setattr(self.__class__, f"ui_getgroup_{group}",
                 lambda self, attr:
                     self.cfnode.get_attr(group, attr))
@@ -66,25 +70,25 @@ class UINode(configshell.ConfigNode):
             t, d = getattr(self.__class__, name, {}).get(attr, ('string', ''))
             self.define_config_group_param(group, attr, t, d, writable)
 
-    def refresh(self):
+    def refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
-        self._children = set([])
+        self._children: set[UINode] = set()
 
-    def status(self):
+    def status(self) -> str:
         '''
         Displays the current node's status summary.
         '''
         return "None"
 
-    def ui_command_refresh(self):
+    def ui_command_refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
         self.refresh()
 
-    def ui_command_status(self):
+    def ui_command_status(self) -> None:
         '''
         Displays the current node's status summary.
 
@@ -94,7 +98,7 @@ class UINode(configshell.ConfigNode):
         '''
         self.shell.log.info(f"Status for {self.path}: {self.status()}")
 
-    def ui_command_saveconfig(self, savefile=None):
+    def ui_command_saveconfig(self, savefile: str | None = None) -> None:
         '''
         Saves the current configuration to a file so that it can be restored
         on next boot.
@@ -102,6 +106,7 @@ class UINode(configshell.ConfigNode):
         node = self
         while node.parent is not None:
             node = node.parent
+        assert isinstance(node.cfnode, nvme.Root)
         node.cfnode.save_to_file(savefile)
 
 
@@ -113,11 +118,12 @@ class UIRootNode(UINode):
         'nqn': ('string', 'Discovery NQN'),
     }
 
-    def __init__(self, shell):
-        UINode.__init__(self, '/', parent=None, cfnode=nvme.Root(),
-                        shell=shell)
+    def __init__(self, shell: Any) -> None:
+        root = nvme.Root()
+        UINode.__init__(self, '/', parent=None, cfnode=root, shell=shell)
+        self.cfnode: nvme.Root = root
 
-    def summary(self):
+    def summary(self) -> tuple[str, bool]:
         '''
         Returns a summary of the root node.
         '''
@@ -128,7 +134,7 @@ class UIRootNode(UINode):
             pass
         return (", ".join(info), True)
 
-    def refresh(self):
+    def refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
@@ -137,7 +143,8 @@ class UIRootNode(UINode):
         UIPortsNode(self)
         UIHostsNode(self)
 
-    def ui_command_restoreconfig(self, savefile=None, clear_existing=False):
+    def ui_command_restoreconfig(self, savefile: str | None = None,
+                                 clear_existing: bool = False) -> None:
         '''
         Restores configuration from a file.
         '''
@@ -153,10 +160,10 @@ class UISubsystemsNode(UINode):
     '''
     A node in the UI representing the subsystems.
     '''
-    def __init__(self, parent):
+    def __init__(self, parent: UINode) -> None:
         UINode.__init__(self, 'subsystems', parent)
 
-    def refresh(self):
+    def refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
@@ -164,7 +171,7 @@ class UISubsystemsNode(UINode):
         for subsys in self.parent.cfnode.subsystems:
             UISubsystemNode(self, subsys)
 
-    def ui_command_create(self, nqn=None):
+    def ui_command_create(self, nqn: str | None = None) -> None:
         '''
         Creates a new target. If I{nqn} is omitted, then the new Subsystem
         will be created using a randomly generated NQN.
@@ -176,7 +183,7 @@ class UISubsystemsNode(UINode):
         subsystem = nvme.Subsystem(nqn, mode='create')
         UISubsystemNode(self, subsystem)
 
-    def ui_command_delete(self, nqn):
+    def ui_command_delete(self, nqn: str) -> None:
         '''
         Recursively deletes the subsystem with the specified I{nqn}, and all
         objects hanging under it.
@@ -200,10 +207,11 @@ class UISubsystemNode(UINode):
         'version': ('string', 'Export version number to hosts'),
     }
 
-    def __init__(self, parent, cfnode):
+    def __init__(self, parent: UINode, cfnode: nvme.Subsystem) -> None:
         UINode.__init__(self, cfnode.nqn, parent, cfnode)
+        self.cfnode: nvme.Subsystem = cfnode
 
-    def refresh(self):
+    def refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
@@ -213,7 +221,7 @@ class UISubsystemNode(UINode):
         if self.cfnode.has_passthru():
             UIPassthruNode(self)
 
-    def summary(self):
+    def summary(self) -> tuple[str, bool]:
         '''
         Returns a summary of the subsystem.
         '''
@@ -233,17 +241,18 @@ class UIPassthruNode(UINode):
         'path': ('string', 'Passthru device path')
     }
 
-    def __init__(self, parent):
+    def __init__(self, parent: UISubsystemNode) -> None:
         passthru = nvme.Passthru(parent.cfnode)
         UINode.__init__(self, 'passthru', parent, passthru)
+        self.cfnode: nvme.Passthru = passthru
 
-    def refresh(self):
+    def refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
         self._children = set([])
 
-    def ui_command_enable(self):
+    def ui_command_enable(self) -> None:
         '''
         Enables the passthru.
         '''
@@ -257,7 +266,7 @@ class UIPassthruNode(UINode):
                 raise configshell.ExecutionError(
                     "The passthru could not be enabled.") from exc
 
-    def ui_command_disable(self):
+    def ui_command_disable(self) -> None:
         '''
         Disables the passthru.
         '''
@@ -271,7 +280,7 @@ class UIPassthruNode(UINode):
                 raise configshell.ExecutionError(
                     "The passthru could not be disabled.") from exc
 
-    def ui_command_clear_ids(self, clear_id):
+    def ui_command_clear_ids(self, clear_id: Any) -> None:
         '''
         If I{clear_id} is set to non-zero then clears the passthru namespace
         unique identifiers EUI/GUID/UUID.
@@ -282,7 +291,7 @@ class UIPassthruNode(UINode):
             raise configshell.ExecutionError(
                 "Failed to set clear_ids for this passthru target.") from exc
 
-    def ui_command_admin_timeout(self, timeout):
+    def ui_command_admin_timeout(self, timeout: Any) -> None:
         '''
         Sets the timeout of admin passthru command.
         '''
@@ -292,7 +301,7 @@ class UIPassthruNode(UINode):
             raise configshell.ExecutionError(
                 "Failed to set the admin passthru command timeout.") from exc
 
-    def ui_command_io_timeout(self, timeout):
+    def ui_command_io_timeout(self, timeout: Any) -> None:
         '''
         Sets the timeout of IO passthru command.
         '''
@@ -302,7 +311,7 @@ class UIPassthruNode(UINode):
             raise configshell.ExecutionError(
                 "Failed to set the IO passthru command timeout.") from exc
 
-    def summary(self):
+    def summary(self) -> tuple[str, bool]:
         info = []
         info.append("path=" + self.cfnode.get_attr("device", "path"))
         if self.cfnode.ids != 0:
@@ -319,10 +328,10 @@ class UINamespacesNode(UINode):
     '''
     A node in the UI representing the namespaces.
     '''
-    def __init__(self, parent):
+    def __init__(self, parent: UINode) -> None:
         UINode.__init__(self, 'namespaces', parent)
 
-    def refresh(self):
+    def refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
@@ -330,7 +339,7 @@ class UINamespacesNode(UINode):
         for ns in self.parent.cfnode.namespaces:
             UINamespaceNode(self, ns)
 
-    def ui_command_create(self, nsid=None):
+    def ui_command_create(self, nsid: Any | None = None) -> None:
         '''
         Creates a new namespace. If I{nsid} is omitted, then the next
         available namespace id will be used.
@@ -342,7 +351,7 @@ class UINamespacesNode(UINode):
         namespace = nvme.Namespace(self.parent.cfnode, nsid, mode='create')
         UINamespaceNode(self, namespace)
 
-    def ui_command_delete(self, nsid):
+    def ui_command_delete(self, nsid: Any) -> None:
         '''
         Recursively deletes the namespace with the specified I{nsid}, and all
         objects hanging under it.
@@ -366,10 +375,11 @@ class UINamespaceNode(UINode):
         'uuid': ('string', 'Namespace Universally Unique Identifier.'),
     }
 
-    def __init__(self, parent, cfnode):
+    def __init__(self, parent: UINode, cfnode: nvme.Namespace) -> None:
         UINode.__init__(self, str(cfnode.nsid), parent, cfnode)
+        self.cfnode: nvme.Namespace = cfnode
 
-    def status(self):
+    def status(self) -> str:
         '''
         Returns the status of the namespace.
         '''
@@ -377,7 +387,7 @@ class UINamespaceNode(UINode):
             return "enabled"
         return "disabled"
 
-    def ui_command_enable(self):
+    def ui_command_enable(self) -> None:
         '''
         Enables the current Namespace.
 
@@ -395,7 +405,7 @@ class UINamespaceNode(UINode):
                 raise configshell.ExecutionError(
                     "The Namespace could not be enabled.") from exc
 
-    def ui_command_disable(self):
+    def ui_command_disable(self) -> None:
         '''
         Disables the current Namespace.
 
@@ -413,7 +423,7 @@ class UINamespaceNode(UINode):
                 raise configshell.ExecutionError(
                     "The Namespace could not be enabled.") from exc
 
-    def ui_command_grpid(self, grpid):
+    def ui_command_grpid(self, grpid: Any) -> None:
         '''
         Sets the ANA Group ID of the current Namespace to I{grpid}
         '''
@@ -423,7 +433,7 @@ class UINamespaceNode(UINode):
             raise configshell.ExecutionError(
                 "Failed to set ANA Group ID for this Namespace.") from exc
 
-    def summary(self):
+    def summary(self) -> tuple[str, Any]:
         info = []
         info.append("path=" + self.cfnode.get_attr("device", "path"))
         ns_uuid = self.cfnode.get_attr("device", "uuid")
@@ -448,10 +458,10 @@ class UIAllowedHostsNode(UINode):
     '''
     A node in the UI representing the allowed hosts.
     '''
-    def __init__(self, parent):
+    def __init__(self, parent: UINode) -> None:
         UINode.__init__(self, 'allowed_hosts', parent)
 
-    def refresh(self):
+    def refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
@@ -459,7 +469,7 @@ class UIAllowedHostsNode(UINode):
         for host in self.parent.cfnode.allowed_hosts:
             UIAllowedHostNode(self, host)
 
-    def ui_command_create(self, nqn):
+    def ui_command_create(self, nqn: str) -> None:
         '''
         Grants access to parent subsystems to the host specified by I{nqn}.
 
@@ -470,7 +480,8 @@ class UIAllowedHostsNode(UINode):
         self.parent.cfnode.add_allowed_host(nqn)
         UIAllowedHostNode(self, nqn)
 
-    def ui_complete_create(self, _parameters, _text, current_param):
+    def ui_complete_create(self, _parameters: dict[str, Any], _text: str,
+                           current_param: str) -> list[str]:
         '''
         Completes the create command.
         '''
@@ -483,7 +494,7 @@ class UIAllowedHostsNode(UINode):
             return [f"{completions[0]} "]
         return completions
 
-    def ui_command_delete(self, nqn):
+    def ui_command_delete(self, nqn: str) -> None:
         '''
         Recursively deletes the namespace with the specified I{nsid}, and all
         objects hanging under it.
@@ -495,7 +506,8 @@ class UIAllowedHostsNode(UINode):
         self.parent.cfnode.remove_allowed_host(nqn)
         self.refresh()
 
-    def ui_complete_delete(self, _parameters, _text, current_param):
+    def ui_complete_delete(self, _parameters: dict[str, Any], _text: str,
+                           current_param: str) -> list[str]:
         '''
         Completes the delete command.
         '''
@@ -513,7 +525,7 @@ class UIAllowedHostNode(UINode):
     '''
     A node in the UI representing an allowed host.
     '''
-    def __init__(self, parent, nqn):
+    def __init__(self, parent: UINode, nqn: str) -> None:
         UINode.__init__(self, nqn, parent)
 
 
@@ -521,10 +533,10 @@ class UIPortsNode(UINode):
     '''
     A node in the UI representing the ports.
     '''
-    def __init__(self, parent):
+    def __init__(self, parent: UINode) -> None:
         UINode.__init__(self, 'ports', parent)
 
-    def refresh(self):
+    def refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
@@ -532,7 +544,7 @@ class UIPortsNode(UINode):
         for port in self.parent.cfnode.ports:
             UIPortNode(self, port)
 
-    def ui_command_create(self, portid=None):
+    def ui_command_create(self, portid: Any | None = None) -> None:
         '''
         Creates a new NVMe port with portid I{portid}.
 
@@ -543,7 +555,7 @@ class UIPortsNode(UINode):
         port = nvme.Port(portid, mode='create')
         UIPortNode(self, port)
 
-    def ui_command_delete(self, portid):
+    def ui_command_delete(self, portid: Any) -> None:
         '''
         Recursively deletes the NVMe Port with the specified I{port}, and all
         objects hanging under it.
@@ -573,8 +585,9 @@ class UIPortNode(UINode):
         'inline_data_size': ('string', 'Port inline data size in bytes'),
     }
 
-    def __init__(self, parent, cfnode):
+    def __init__(self, parent: UINode, cfnode: nvme.Port) -> None:
         UINode.__init__(self, str(cfnode.portid), parent, cfnode)
+        self.cfnode: nvme.Port = cfnode
         UIPortSubsystemsNode(self)
         try:
             next(cfnode.ana_groups)
@@ -584,7 +597,7 @@ class UIPortNode(UINode):
             UIANAGroupsNode(self)
         UIReferralsNode(self)
 
-    def summary(self):
+    def summary(self) -> tuple[str, Any]:
         '''
         Returns a summary of the port.
         '''
@@ -610,10 +623,10 @@ class UIPortSubsystemsNode(UINode):
     '''
     A node in the UI representing the port subsystems.
     '''
-    def __init__(self, parent):
+    def __init__(self, parent: UINode) -> None:
         UINode.__init__(self, 'subsystems', parent)
 
-    def refresh(self):
+    def refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
@@ -621,7 +634,7 @@ class UIPortSubsystemsNode(UINode):
         for host in self.parent.cfnode.subsystems:
             UIPortSubsystemNode(self, host)
 
-    def ui_command_create(self, nqn):
+    def ui_command_create(self, nqn: str) -> None:
         '''
         Grants access to the subsystem specified by I{nqn} through the
         parent port.
@@ -633,7 +646,8 @@ class UIPortSubsystemsNode(UINode):
         self.parent.cfnode.add_subsystem(nqn)
         UIPortSubsystemNode(self, nqn)
 
-    def ui_complete_create(self, _parameters, _text, current_param):
+    def ui_complete_create(self, _parameters: dict[str, Any], _text: str,
+                           current_param: str) -> list[str]:
         '''
         Completes the create command.
         '''
@@ -646,7 +660,7 @@ class UIPortSubsystemsNode(UINode):
             return [f"{completions[0]} "]
         return completions
 
-    def ui_command_delete(self, nqn):
+    def ui_command_delete(self, nqn: str) -> None:
         '''
         Removes access to the subsystem specified by I{nqn} through the
         parent port.
@@ -658,7 +672,8 @@ class UIPortSubsystemsNode(UINode):
         self.parent.cfnode.remove_subsystem(nqn)
         self.refresh()
 
-    def ui_complete_delete(self, _parameters, _text, current_param):
+    def ui_complete_delete(self, _parameters: dict[str, Any], _text: str,
+                           current_param: str) -> list[str]:
         '''
         Completes the delete command.
         '''
@@ -676,7 +691,7 @@ class UIPortSubsystemNode(UINode):
     '''
     A node in the UI representing a port subsystem.
     '''
-    def __init__(self, parent, nqn):
+    def __init__(self, parent: UINode, nqn: str) -> None:
         UINode.__init__(self, nqn, parent)
 
 
@@ -684,10 +699,10 @@ class UIReferralsNode(UINode):
     '''
     A node in the UI representing the referrals.
     '''
-    def __init__(self, parent):
+    def __init__(self, parent: UINode) -> None:
         UINode.__init__(self, 'referrals', parent)
 
-    def refresh(self):
+    def refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
@@ -695,7 +710,7 @@ class UIReferralsNode(UINode):
         for r in self.parent.cfnode.referrals:
             UIReferralNode(self, r)
 
-    def ui_command_create(self, name):
+    def ui_command_create(self, name: str) -> None:
         '''
         Creates a new referral.
 
@@ -706,7 +721,7 @@ class UIReferralsNode(UINode):
         r = nvme.Referral(self.parent.cfnode, name, mode='create')
         UIReferralNode(self, r)
 
-    def ui_command_delete(self, name):
+    def ui_command_delete(self, name: str) -> None:
         '''
         Deletes the referral with the specified I{name}.
 
@@ -733,10 +748,11 @@ class UIReferralNode(UINode):
         'portid': ('number', 'Port identifier'),
     }
 
-    def __init__(self, parent, cfnode):
+    def __init__(self, parent: UINode, cfnode: nvme.Referral) -> None:
         UINode.__init__(self, cfnode.name, parent, cfnode)
+        self.cfnode: nvme.Referral = cfnode
 
-    def status(self):
+    def status(self) -> str:
         '''
         Returns the status of the referral.
         '''
@@ -744,7 +760,7 @@ class UIReferralNode(UINode):
             return "enabled"
         return "disabled"
 
-    def ui_command_enable(self):
+    def ui_command_enable(self) -> None:
         '''
         Enables the current Referral.
 
@@ -762,7 +778,7 @@ class UIReferralNode(UINode):
                 raise configshell.ExecutionError(
                     "The Referral could not be enabled.") from exc
 
-    def ui_command_disable(self):
+    def ui_command_disable(self) -> None:
         '''
         Disables the current Referral.
 
@@ -785,10 +801,10 @@ class UIANAGroupsNode(UINode):
     '''
     A node in the UI representing the ANA groups.
     '''
-    def __init__(self, parent):
+    def __init__(self, parent: UINode) -> None:
         UINode.__init__(self, 'ana_groups', parent)
 
-    def refresh(self):
+    def refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
@@ -796,7 +812,7 @@ class UIANAGroupsNode(UINode):
         for a in self.parent.cfnode.ana_groups:
             UIANAGroupNode(self, a)
 
-    def ui_command_create(self, grpid):
+    def ui_command_create(self, grpid: Any) -> None:
         '''
         Creates a new ANA Group.
 
@@ -807,7 +823,7 @@ class UIANAGroupsNode(UINode):
         a = nvme.ANAGroup(self.parent.cfnode, grpid, mode='create')
         UIANAGroupNode(self, a)
 
-    def ui_command_delete(self, grpid):
+    def ui_command_delete(self, grpid: Any) -> None:
         '''
         Deletes the ANA Group with the specified I{name}.
 
@@ -828,10 +844,11 @@ class UIANAGroupNode(UINode):
         'state': ('string', 'ANA state'),
     }
 
-    def __init__(self, parent, cfnode):
+    def __init__(self, parent: UINode, cfnode: nvme.ANAGroup) -> None:
         UINode.__init__(self, str(cfnode.grpid), parent, cfnode)
+        self.cfnode: nvme.ANAGroup = cfnode
 
-    def summary(self):
+    def summary(self) -> tuple[str, bool]:
         '''
         Returns a summary of the ANA group.
         '''
@@ -844,10 +861,10 @@ class UIHostsNode(UINode):
     '''
     A node in the UI representing the hosts.
     '''
-    def __init__(self, parent):
+    def __init__(self, parent: UINode) -> None:
         UINode.__init__(self, 'hosts', parent)
 
-    def refresh(self):
+    def refresh(self) -> None:
         '''
         Refreshes and updates the objects tree from the current path.
         '''
@@ -855,7 +872,7 @@ class UIHostsNode(UINode):
         for host in self.parent.cfnode.hosts:
             UIHostNode(self, host)
 
-    def ui_command_create(self, nqn):
+    def ui_command_create(self, nqn: str) -> None:
         '''
         Creates a new NVMe host.
 
@@ -866,7 +883,7 @@ class UIHostsNode(UINode):
         host = nvme.Host(nqn, mode='create')
         UIHostNode(self, host)
 
-    def ui_command_delete(self, nqn):
+    def ui_command_delete(self, nqn: str) -> None:
         '''
         Recursively deletes the NVMe Host with the specified I{nqn}, and all
         objects hanging under it.
@@ -884,11 +901,12 @@ class UIHostNode(UINode):
     '''
     A node in the UI representing a host.
     '''
-    def __init__(self, parent, cfnode):
+    def __init__(self, parent: UINode, cfnode: nvme.Host) -> None:
         UINode.__init__(self, cfnode.nqn, parent, cfnode)
+        self.cfnode: nvme.Host = cfnode
 
 
-def usage():
+def usage() -> None:
     '''
     Prints the usage message.
     '''
@@ -900,14 +918,14 @@ def usage():
     sys.exit(-1)
 
 
-def save(to_file):
+def save(to_file: str | None) -> None:
     '''
     Saves the configuration to a file.
     '''
     nvme.Root().save_to_file(to_file)
 
 
-def restore(from_file):
+def restore(from_file: str | None) -> None:
     '''
     Restores the configuration from a file.
     '''
@@ -935,14 +953,14 @@ def restore(from_file):
     sys.exit(0)
 
 
-def clear(_unused):
+def clear(_unused: str | None) -> None:
     '''
     Clears the configuration.
     '''
     nvme.Root().clear_existing()
 
 
-def execute_cmd(cmd):
+def execute_cmd(cmd: str) -> None:
     '''
     Executes a command in the shell.
     '''
@@ -952,10 +970,12 @@ def execute_cmd(cmd):
     sys.exit(0)
 
 
-funcs = {'save': save, 'restore': restore, 'clear': clear}
+funcs: dict[str, Callable[[str | None], None]] = {
+    'save': save, 'restore': restore, 'clear': clear,
+}
 
 
-def main():
+def main() -> None:
     '''
     The main function.
     '''
@@ -994,3 +1014,5 @@ def main():
 
 if __name__ == "__main__":
     main()
+
+# pylint: disable=too-many-lines
diff --git a/pyproject.toml b/pyproject.toml
index c0f429b..43b7db1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -24,3 +24,27 @@ test = [
     "nose2",
     "coverage"
 ]
+typecheck = [
+    "mypy"
+]
+
+[tool.mypy]
+files = ["nvmet", "nvmetcli"]
+disallow_untyped_defs = true
+disallow_incomplete_defs = true
+check_untyped_defs = true
+disallow_untyped_decorators = true
+no_implicit_reexport = true
+warn_redundant_casts = true
+warn_unused_ignores = true
+warn_unreachable = true
+warn_return_any = true
+strict_equality = true
+# Not full `strict = true`: configshell ships no type stubs, so its
+# ConfigNode is typed as Any, and disallow_subclassing_any would flag
+# every configshell.ConfigNode subclass in nvmetcli. Everything else
+# strict mode enables is clean and enforced above.
+
+[[tool.mypy.overrides]]
+module = "configshell.*"
+ignore_missing_imports = true