diff --git a/.github/workflows/python_actions.yml b/.github/workflows/python_actions.yml
index 883873b..eb1e109 100644
--- a/.github/workflows/python_actions.yml
+++ b/.github/workflows/python_actions.yml
@@ -45,7 +45,8 @@ jobs:
         python-version: ${{ matrix.python-version }}
     - name: Install pip, etc
       uses: ./support/actions/python-tools
-
+    - name: Install mypy
+      run: pip install mypy
     - name: Install Spinnaker Dependencies
       uses: ./support/actions/install-spinn-deps
       with:
@@ -91,3 +92,6 @@ jobs:
     #  uses: ./support/actions/sphinx
     #  with:
     #    directory: doc/source
+
+    - name: Lint with mypy
+      run: mypy spinn_pdp2
diff --git a/__init__.py b/__init__.py
deleted file mode 100644
index c617e64..0000000
--- a/__init__.py
+++ /dev/null
@@ -1,15 +0,0 @@
-# Copyright (c) 2015 The University of Manchester
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
diff --git a/spinn_pdp2/input_vertex.py b/spinn_pdp2/input_vertex.py
index 1c6460e..1ad1184 100644
--- a/spinn_pdp2/input_vertex.py
+++ b/spinn_pdp2/input_vertex.py
@@ -14,8 +14,12 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 import struct
+from typing import Iterable, Optional
+
+from spinn_machine.tags import IPTag, ReverseIPTag
 
 from pacman.model.graphs.machine.machine_vertex import MachineVertex
+from pacman.model.placements import Placement
 from pacman.model.resources import ConstantSDRAM
 
 from spinn_utilities.overrides import overrides
@@ -25,7 +29,8 @@
 from spinn_front_end_common.abstract_models.impl \
     import MachineDataSpecableVertex
 from spinn_front_end_common.data import FecDataView
-from spinn_front_end_common.interface.ds import DataType
+from spinn_front_end_common.interface.ds import (
+    DataSpecificationGenerator, DataSpecificationReloader, DataType)
 from spinn_front_end_common.utilities.constants \
     import SYSTEM_BYTES_REQUIREMENT
 
@@ -193,17 +198,18 @@ def config (self):
 
     @property
     @overrides (MachineVertex.sdram_required)
-    def sdram_required (self):
+    def sdram_required (self) -> ConstantSDRAM:
         return ConstantSDRAM(SYSTEM_BYTES_REQUIREMENT + self._sdram_usage)
 
     @overrides (MachineVertex.get_n_keys_for_partition)
-    def get_n_keys_for_partition (self, partition_id):
+    def get_n_keys_for_partition(self, partition_id: str) -> int:
         return MLPConstants.KEY_SPACE_SIZE
 
-
     @overrides(MachineDataSpecableVertex.generate_machine_data_specification)
     def generate_machine_data_specification(
-            self, spec, placement, iptags, reverse_iptags):
+            self, spec: DataSpecificationGenerator, placement: Placement,
+            iptags: Optional[Iterable[IPTag]],
+            reverse_iptags: Optional[Iterable[ReverseIPTag]]):
         routing_info = FecDataView.get_routing_infos()
 
         # Generate the system data region for simulation.c requirements
@@ -288,12 +294,16 @@ def generate_machine_data_specification(
         spec.switch_write_focus (MLPRegions.ROUTING.value)
 
         # write link keys: fwd
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.fwd_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex(
+            self, self.fwd_link)
+        assert key is not None
+        spec.write_value(key, data_type=DataType.UINT32)
 
         # write link keys: bkp
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.bkp_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex(
+            self, self.bkp_link)
+        assert key is not None
+        spec.write_value (key, data_type = DataType.UINT32)
 
         # write link keys: bps (padding)
         spec.write_value (0, data_type = DataType.UINT32)
@@ -321,7 +331,8 @@ def generate_machine_data_specification(
 
 
     @overrides(AbstractRewritesDataSpecification.regenerate_data_specification)
-    def regenerate_data_specification(self, spec, placement):
+    def regenerate_data_specification(
+            self, spec: DataSpecificationReloader, placement: Placement):
         # Reserve and write the stage configuration region
         spec.reserve_memory_region (MLPRegions.STAGE.value,
                                     self._STAGE_CONFIGURATION_BYTES)
@@ -336,12 +347,12 @@ def regenerate_data_specification(self, spec, placement):
 
 
     @overrides(AbstractRewritesDataSpecification.reload_required)
-    def reload_required(self):
+    def reload_required(self) -> bool:
         return True
 
 
     @overrides(AbstractRewritesDataSpecification.set_reload_required)
-    def set_reload_required(self, new_value):
+    def set_reload_required(self, new_value: bool):
         """
             TODO: not really sure what this method is used for!
         """
diff --git a/spinn_pdp2/py.typed b/spinn_pdp2/py.typed
new file mode 100644
index 0000000..91eaa0c
--- /dev/null
+++ b/spinn_pdp2/py.typed
@@ -0,0 +1,13 @@
+# Copyright (c) 2023 The University of Manchester
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
diff --git a/spinn_pdp2/sum_vertex.py b/spinn_pdp2/sum_vertex.py
index c302c46..9158283 100644
--- a/spinn_pdp2/sum_vertex.py
+++ b/spinn_pdp2/sum_vertex.py
@@ -14,11 +14,15 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 import struct
+from typing import Iterable, Optional
+
+from spinn_machine.tags import IPTag, ReverseIPTag
 
 import spinnaker_graph_front_end as gfe
 
 from pacman.model.graphs.machine import MachineEdge
 from pacman.model.graphs.machine.machine_vertex import MachineVertex
+from pacman.model.placements import Placement
 from pacman.model.resources import ConstantSDRAM
 
 from spinn_utilities.overrides import overrides
@@ -28,7 +32,8 @@
 from spinn_front_end_common.abstract_models.impl \
     import MachineDataSpecableVertex
 from spinn_front_end_common.data import FecDataView
-from spinn_front_end_common.interface.ds import DataType
+from spinn_front_end_common.interface.ds import (
+    DataSpecificationGenerator, DataSpecificationReloader, DataType)
 from spinn_front_end_common.utilities.constants \
     import SYSTEM_BYTES_REQUIREMENT
 
@@ -248,18 +253,20 @@ def config (self):
 
     @property
     @overrides (MachineVertex.sdram_required)
-    def sdram_required (self):
+    def sdram_required (self) -> ConstantSDRAM:
         return ConstantSDRAM(SYSTEM_BYTES_REQUIREMENT + self._sdram_usage)
 
 
     @overrides (MachineVertex.get_n_keys_for_partition)
-    def get_n_keys_for_partition (self, partition_id):
+    def get_n_keys_for_partition(self, partition_id: str) -> int:
         return MLPConstants.KEY_SPACE_SIZE
 
 
     @overrides(MachineDataSpecableVertex.generate_machine_data_specification)
     def generate_machine_data_specification(
-            self, spec, placement, iptags, reverse_iptags):
+            self, spec: DataSpecificationGenerator, placement: Placement,
+            iptags: Optional[Iterable[IPTag]],
+            reverse_iptags: Optional[Iterable[ReverseIPTag]]):
         routing_info = FecDataView.get_routing_infos()
         # Generate the system data region for simulation.c requirements
         generate_steps_system_data_region(spec, MLPRegions.SYSTEM.value, self)
@@ -312,12 +319,16 @@ def generate_machine_data_specification(
         spec.switch_write_focus (MLPRegions.ROUTING.value)
 
         # write link keys: fwd
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.fwd_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex(
+            self, self.fwd_link)
+        assert key is not None
+        spec.write_value(key, data_type=DataType.UINT32)
 
         # write link keys: bkp
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.bkp_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex(
+            self, self.bkp_link)
+        assert key is not None
+        spec.write_value(key, data_type=DataType.UINT32)
 
         # write link keys: bps (padding)
         spec.write_value (0, data_type = DataType.UINT32)
@@ -326,12 +337,16 @@ def generate_machine_data_specification(
         spec.write_value (0, data_type = DataType.UINT32)
 
         # write link keys: lds
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.lds_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex(
+            self, self.lds_link)
+        assert key is not None
+        spec.write_value(key, data_type=DataType.UINT32)
 
         # write link keys: fsg
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.fsg_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex (
+            self, self.fsg_link)
+        assert key is not None
+        spec.write_value(key, data_type=DataType.UINT32)
 
         # Reserve and write the stage configuration region
         spec.reserve_memory_region (MLPRegions.STAGE.value,
@@ -347,7 +362,8 @@ def generate_machine_data_specification(
 
 
     @overrides(AbstractRewritesDataSpecification.regenerate_data_specification)
-    def regenerate_data_specification(self, spec, placement):
+    def regenerate_data_specification(
+            self, spec: DataSpecificationReloader, placement: Placement):
         # Reserve and write the stage configuration region
         spec.reserve_memory_region (MLPRegions.STAGE.value,
                                     self._STAGE_CONFIGURATION_BYTES)
@@ -362,12 +378,12 @@ def regenerate_data_specification(self, spec, placement):
 
 
     @overrides(AbstractRewritesDataSpecification.reload_required)
-    def reload_required(self):
+    def reload_required(self) -> bool:
         return True
 
 
     @overrides(AbstractRewritesDataSpecification.set_reload_required)
-    def set_reload_required(self, new_value):
+    def set_reload_required(self, new_value: bool):
         """
             TODO: not really sure what this method is used for!
         """
diff --git a/spinn_pdp2/threshold_vertex.py b/spinn_pdp2/threshold_vertex.py
index 7bd5b7e..e290738 100644
--- a/spinn_pdp2/threshold_vertex.py
+++ b/spinn_pdp2/threshold_vertex.py
@@ -14,9 +14,13 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 import struct
+from typing import Iterable, List, Optional
+
+from spinn_machine.tags import IPTag, ReverseIPTag
 
 from pacman.model.graphs.machine.machine_vertex import MachineVertex
-from pacman.model.resources import VariableSDRAM, ConstantSDRAM
+from pacman.model.placements import Placement
+from pacman.model.resources import AbstractSDRAM, ConstantSDRAM, VariableSDRAM
 
 from spinn_utilities.overrides import overrides
 
@@ -25,7 +29,8 @@
 from spinn_front_end_common.abstract_models.impl \
     import MachineDataSpecableVertex
 from spinn_front_end_common.data import FecDataView
-from spinn_front_end_common.interface.ds import DataType
+from spinn_front_end_common.interface.ds import (
+    DataSpecificationGenerator, DataSpecificationReloader, DataType)
 from spinn_front_end_common.utilities.constants \
     import SYSTEM_BYTES_REQUIREMENT, BYTES_PER_WORD
 from spinn_front_end_common.interface.buffer_management.buffer_models import (
@@ -341,7 +346,7 @@ def config (self):
 
     @property
     @overrides (MachineVertex.sdram_required)
-    def sdram_required (self):
+    def sdram_required (self) -> AbstractSDRAM:
         if self.group.output_grp:
              return VariableSDRAM(self._sdram_fixed, self._sdram_variable)
         else:
@@ -349,7 +354,7 @@ def sdram_required (self):
 
 
     @overrides (MachineVertex.get_n_keys_for_partition)
-    def get_n_keys_for_partition (self, partition_id):
+    def get_n_keys_for_partition(self, partition_id: str) -> int:
         return MLPConstants.KEY_SPACE_SIZE
 
 
@@ -373,7 +378,9 @@ def read(self, placement, buffer_manager, channel):
 
     @overrides(MachineDataSpecableVertex.generate_machine_data_specification)
     def generate_machine_data_specification(
-            self, spec, placement, iptags, reverse_iptags):
+            self, spec: DataSpecificationGenerator, placement: Placement,
+            iptags: Optional[Iterable[IPTag]],
+            reverse_iptags: Optional[Iterable[ReverseIPTag]]):
         routing_info = FecDataView.get_routing_infos()
         # Generate the system data region for simulation.c requirements
         generate_steps_system_data_region(spec, MLPRegions.SYSTEM.value, self)
@@ -477,19 +484,25 @@ def generate_machine_data_specification(
         spec.switch_write_focus (MLPRegions.ROUTING.value)
 
         # write link keys: fwd
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.fwd_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex(
+            self, self.fwd_link)
+        assert key is not None
+        spec.write_value(key, data_type=DataType.UINT32)
 
         # write link keys: bkp
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.bkp_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex(
+            self, self.bkp_link)
+        assert key is not None
+        spec.write_value (key, data_type = DataType.UINT32)
 
         # write link keys: bps (padding)
         spec.write_value (0, data_type = DataType.UINT32)
 
         # write link keys: stp
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.stp_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex(
+            self, self.stp_link)
+        assert key is not None
+        spec.write_value(key, data_type=DataType.UINT32)
 
         # write link keys: lds (padding)
         spec.write_value (0, data_type = DataType.UINT32)
@@ -531,7 +544,8 @@ def generate_machine_data_specification(
 
 
     @overrides(AbstractRewritesDataSpecification.regenerate_data_specification)
-    def regenerate_data_specification(self, spec, placement):
+    def regenerate_data_specification(
+            self, spec: DataSpecificationReloader, placement: Placement):
         # reserve and write the stage configuration region
         spec.reserve_memory_region (MLPRegions.STAGE.value,
                                     self._STAGE_CONFIGURATION_BYTES)
@@ -546,12 +560,12 @@ def regenerate_data_specification(self, spec, placement):
 
 
     @overrides(AbstractRewritesDataSpecification.reload_required)
-    def reload_required(self):
+    def reload_required(self) -> bool:
         return True
 
 
     @overrides(AbstractRewritesDataSpecification.set_reload_required)
-    def set_reload_required(self, new_value):
+    def set_reload_required(self, new_value: bool):
         """
             TODO: not really sure what this method is used for!
         """
@@ -560,7 +574,7 @@ def set_reload_required(self, new_value):
 
 
     @overrides(AbstractReceiveBuffersToHost.get_recorded_region_ids)
-    def get_recorded_region_ids(self):
+    def get_recorded_region_ids(self) -> List[int]:
         if self.group.output_grp:
             ids = [ch.value for ch in MLPVarSizeRecordings]
             ids.extend([ch.value for ch in MLPConstSizeRecordings])
@@ -575,6 +589,6 @@ def get_recorded_region_ids(self):
 
 
     @overrides(AbstractReceiveBuffersToHost.get_recording_region_base_address)
-    def get_recording_region_base_address(self, placement):
+    def get_recording_region_base_address(self, placement: Placement) -> int:
         return locate_memory_region_for_placement(
             placement, MLPRegions.REC_INFO.value)
diff --git a/spinn_pdp2/weight_vertex.py b/spinn_pdp2/weight_vertex.py
index 6d036d5..f7598dd 100644
--- a/spinn_pdp2/weight_vertex.py
+++ b/spinn_pdp2/weight_vertex.py
@@ -14,8 +14,12 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 import struct
+from typing import Iterable, Optional
+
+from spinn_machine.tags import IPTag, ReverseIPTag
 
 from pacman.model.graphs.machine.machine_vertex import MachineVertex
+from pacman.model.placements import Placement
 from pacman.model.resources import ConstantSDRAM
 
 from spinn_utilities.overrides import overrides
@@ -25,7 +29,8 @@
 from spinn_front_end_common.abstract_models.impl \
     import MachineDataSpecableVertex
 from spinn_front_end_common.data import FecDataView
-from spinn_front_end_common.interface.ds import DataType
+from spinn_front_end_common.interface.ds import (
+    DataSpecificationGenerator, DataSpecificationReloader, DataType)
 from spinn_front_end_common.utilities.constants \
     import SYSTEM_BYTES_REQUIREMENT
 
@@ -259,18 +264,20 @@ def config (self):
 
     @property
     @overrides (MachineVertex.sdram_required)
-    def sdram_required (self):
+    def sdram_required (self) -> ConstantSDRAM:
         return ConstantSDRAM(SYSTEM_BYTES_REQUIREMENT + self._sdram_usage)
 
 
     @overrides (MachineVertex.get_n_keys_for_partition)
-    def get_n_keys_for_partition (self, partition_id):
+    def get_n_keys_for_partition(self, partition_id: str) -> int:
         return MLPConstants.KEY_SPACE_SIZE
 
 
     @overrides(MachineDataSpecableVertex.generate_machine_data_specification)
     def generate_machine_data_specification(
-            self, spec, placement, iptags, reverse_iptags):
+            self, spec: DataSpecificationGenerator, placement: Placement,
+            iptags: Optional[Iterable[IPTag]],
+            reverse_iptags: Optional[Iterable[ReverseIPTag]]):
 
         routing_info = FecDataView.get_routing_infos()
         # Generate the system data region for simulation.c requirements
@@ -346,12 +353,16 @@ def generate_machine_data_specification(
         spec.switch_write_focus (MLPRegions.ROUTING.value)
 
         # write link keys: fwd
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.fwd_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex(
+            self, self.fwd_link)
+        assert key is not None
+        spec.write_value(key, data_type=DataType.UINT32)
 
         # write link keys: bkp
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.bkp_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex(
+            self, self.bkp_link)
+        assert key is not None
+        spec.write_value(key, data_type=DataType.UINT32)
 
         # write link keys: bps (padding)
         spec.write_value (0, data_type = DataType.UINT32)
@@ -360,12 +371,16 @@ def generate_machine_data_specification(
         spec.write_value (0, data_type = DataType.UINT32)
 
         # write link keys: lds
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.lds_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex(
+            self, self.lds_link)
+        assert key is not None
+        spec.write_value(key, data_type=DataType.UINT32)
 
         # write link keys: fsg
-        spec.write_value (routing_info.get_first_key_from_pre_vertex (
-            self, self.fsg_link), data_type = DataType.UINT32)
+        key = routing_info.get_first_key_from_pre_vertex(
+            self, self.fsg_link)
+        assert key is not None
+        spec.write_value(key, data_type=DataType.UINT32)
 
         # Reserve and write the stage configuration region
         spec.reserve_memory_region (MLPRegions.STAGE.value,
@@ -381,7 +396,8 @@ def generate_machine_data_specification(
 
 
     @overrides(AbstractRewritesDataSpecification.regenerate_data_specification)
-    def regenerate_data_specification(self, spec, placement):
+    def regenerate_data_specification(
+            self, spec: DataSpecificationReloader, placement: Placement):
         # Reserve and write the stage configuration region
         spec.reserve_memory_region (MLPRegions.STAGE.value,
                                     self._STAGE_CONFIGURATION_BYTES)
@@ -396,12 +412,12 @@ def regenerate_data_specification(self, spec, placement):
 
 
     @overrides(AbstractRewritesDataSpecification.reload_required)
-    def reload_required(self):
+    def reload_required(self) -> bool:
         return True
 
 
     @overrides(AbstractRewritesDataSpecification.set_reload_required)
-    def set_reload_required(self, new_value):
+    def set_reload_required(self, new_value: bool):
         """
             TODO: not really sure what this method is used for!
         """