diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index cd6dbeb..2121027 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -16,4 +16,5 @@ repos:
     rev: v0.910
     hooks:
     - id: mypy
-      language_version: python
\ No newline at end of file
+      language_version: python
+      args: [--install-types, --non-interactive]
\ No newline at end of file
diff --git a/oaff/app/oaff/app/data/sources/common/data_source_manager.py b/oaff/app/oaff/app/data/sources/common/data_source_manager.py
index 2248726..17fa22e 100644
--- a/oaff/app/oaff/app/data/sources/common/data_source_manager.py
+++ b/oaff/app/oaff/app/data/sources/common/data_source_manager.py
@@ -6,5 +6,5 @@
 
 class DataSourceManager(ABC):
     @abstractmethod
-    def get_data_sources() -> List[Type[DataSource]]:
+    def get_data_sources(self) -> List[Type[DataSource]]:
         pass
diff --git a/oaff/app/oaff/app/data/sources/postgresql/stac_hybrid/postgresql_data_source.py b/oaff/app/oaff/app/data/sources/postgresql/stac_hybrid/postgresql_data_source.py
index a5bd224..3753052 100644
--- a/oaff/app/oaff/app/data/sources/postgresql/stac_hybrid/postgresql_data_source.py
+++ b/oaff/app/oaff/app/data/sources/postgresql/stac_hybrid/postgresql_data_source.py
@@ -2,7 +2,7 @@
 from hashlib import sha256
 from logging import getLogger
 from os import path
-from typing import Any, Coroutine, Dict, Final, List, Type
+from typing import Any, Awaitable, Callable, Dict, Final, List, Type
 
 # geoalchemy import required for sa.MetaData reflection, even though unused in module
 import geoalchemy2 as ga  # noqa: F401
@@ -51,7 +51,7 @@ class PostgresqlDataSource(DataSource):
     def __init__(
         self,
         connection_name: str,
-        connection_tester: Coroutine[None, None, Database],
+        connection_tester: Callable[[Database, str], Awaitable[None]],
     ):
         super().__init__(f"{self.DATA_SOURCE_NAME}:{connection_name}")
         self.db = Database(settings.url(connection_name))
@@ -155,7 +155,7 @@ def get_if_available(
     async def get_feature_set_provider(
         self,
         layer: PostgresqlLayer,
-        constraints: ItemConstraints = None,
+        constraints: ItemConstraints,
         ast: Type[Node] = None,
     ) -> Type[FeatureSetProvider]:
         filters = (
@@ -414,8 +414,8 @@ async def _get_table_temporal_extents(  # noqa: C901
         self,
         table_models: Dict[str, sa.Table],
         table_temporal_fields: Dict[str, List[TemporalInstant]],
-    ) -> Dict[str, List[datetime]]:
-        table_temporal_extents = {}
+    ) -> Dict[str, List[List[datetime]]]:
+        table_temporal_extents: Dict[str, List[List[datetime]]] = {}
         for qualified_table_name, temporal_fields in table_temporal_fields.items():
             start = None
             end = None
diff --git a/oaff/app/oaff/app/gateway.py b/oaff/app/oaff/app/gateway.py
index 98843fd..ee2d31c 100644
--- a/oaff/app/oaff/app/gateway.py
+++ b/oaff/app/oaff/app/gateway.py
@@ -7,15 +7,11 @@
 from oaff.app.request_handlers.collection_items import (
     CollectionsItems as CollectionsItemsRequestHandler,
 )
-from oaff.app.request_handlers.collections_list import (
-    CollectionsList as CollectionsListRequestHandler,
-)
+from oaff.app.request_handlers.collections_list import CollectionsListRequestHandler
 from oaff.app.request_handlers.common.request_handler import RequestHandler
-from oaff.app.request_handlers.conformance import Conformance as ConformanceRequestHandler
+from oaff.app.request_handlers.conformance import ConformanceRequestHandler
 from oaff.app.request_handlers.feature import Feature as FeatureRequestHandler
-from oaff.app.request_handlers.landing_page import (
-    LandingPage as LandingPageRequestHandler,
-)
+from oaff.app.request_handlers.landing_page import LandingPageRequestHandler
 from oaff.app.requests.common.request_type import RequestType
 from oaff.app.responses.response import Response
 
diff --git a/oaff/app/oaff/app/request_handlers/collection_items.py b/oaff/app/oaff/app/request_handlers/collection_items.py
index 1aac299..a9f9226 100644
--- a/oaff/app/oaff/app/request_handlers/collection_items.py
+++ b/oaff/app/oaff/app/request_handlers/collection_items.py
@@ -1,5 +1,5 @@
 from datetime import datetime, tzinfo
-from typing import Any, Callable, Dict, List, Optional, Tuple, Type, Union
+from typing import Any, Callable, Dict, Optional, Tuple, Type, Union, cast
 
 from pygeofilter.ast import (
     And,
@@ -82,7 +82,7 @@ def _get_page_link_retriever(
 
         frontend_config = get_frontend_configuration()
 
-        def retriever(total_count: int, result_count: int) -> List[Link]:
+        def retriever(total_count: int, result_count: int) -> Dict[PageLinkRel, Link]:
             links = {}
             if request.offset > 0:
                 links[PageLinkRel.PREV] = Link(
@@ -107,7 +107,7 @@ def _collect_ast(
         self,
         bbox: BBox,
         datetime: Any,
-    ) -> Type[Node]:
+    ) -> Optional[Type[Node]]:
         if bbox is None and datetime is None:
             return None
         else:
@@ -120,21 +120,23 @@ def _collect_ast(
 
     async def _spatial_bounds_to_node(
         self,
-        spatial_bounds: Optional[
-            Union[
-                Tuple[float, float, float, float],
-                Tuple[float, float, float, float, float, float],
-            ]
+        spatial_bounds: Union[
+            Tuple[float, float, float, float],
+            Tuple[float, float, float, float, float, float],
         ],
         spatial_bounds_crs: str,
         data_source: DataSource,
         layer: Layer,
     ) -> BBox:
-        x_min, y_min, x_max, y_max = (
-            spatial_bounds
-            if len(spatial_bounds) == 4
-            else (spatial_bounds[i] for i in [0, 1, 3, 4])
-        )
+        # recommended usage for Union of types
+        # https://github.com/python/mypy/issues/1178#issuecomment-176185607
+        if len(spatial_bounds) == 4:
+            a, b, c, d = cast(Tuple[float, float, float, float], spatial_bounds)
+        else:
+            a, b, _, c, d, _ = cast(
+                Tuple[float, float, float, float, float, float], spatial_bounds
+            )
+        x_min, y_min, x_max, y_max = (a, b, c, d)
         transformer = Transformer.from_crs(
             "EPSG:4326",  # True until Features API spec part 2 is implemented
             f"{layer.geometry_crs_auth_name}:{layer.geometry_crs_auth_code}",
@@ -155,13 +157,13 @@ async def _datetime_to_node(  # noqa: C901
         self,
         temporal_bounds: Union[Tuple[datetime], Tuple[datetime, datetime]],
         layer: Layer,
-    ) -> Type[Node]:
+    ) -> Optional[Type[Node]]:
         if len(list(filter(lambda bound: bound is not None, temporal_bounds))) == 0:
             return None
         nodes = []
         for data_field in layer.temporal_attributes:
             if len(temporal_bounds) == 2:
-                query_start, query_end = temporal_bounds
+                query_start, query_end = cast(Tuple[datetime, datetime], temporal_bounds)
                 if data_field.__class__ is TemporalInstant:
                     if query_start is not None and query_end is not None:
                         nodes.append(
@@ -333,6 +335,6 @@ def _match_query_time_to_end_field(
         )
 
     def _match_query_time_to(
-        self, query_time: datetime, tz_aware: bool, tz: Type[tzinfo]
+        self, query_time: datetime, tz_aware: bool, tz: tzinfo
     ) -> datetime:
         return query_time if tz_aware else query_time.astimezone(tz).replace(tzinfo=None)
diff --git a/oaff/app/oaff/app/request_handlers/collections_list.py b/oaff/app/oaff/app/request_handlers/collections_list.py
index 73cf644..390a3c9 100644
--- a/oaff/app/oaff/app/request_handlers/collections_list.py
+++ b/oaff/app/oaff/app/request_handlers/collections_list.py
@@ -3,7 +3,7 @@
 
 from oaff.app.configuration.data import get_layers
 from oaff.app.request_handlers.common.request_handler import RequestHandler
-from oaff.app.requests.collections_list import CollectionsList
+from oaff.app.requests.collections_list import CollectionsList as CollectionsListRequest
 from oaff.app.responses.models.collection import CollectionHtml, CollectionJson
 from oaff.app.responses.models.collections import CollectionsHtml, CollectionsJson
 from oaff.app.responses.response import Response
@@ -12,12 +12,12 @@
 LOGGER: Final = getLogger(__file__)
 
 
-class CollectionsList(RequestHandler):
+class CollectionsListRequestHandler(RequestHandler):
     @classmethod
     def type_name(cls) -> str:
-        return CollectionsList.__name__
+        return CollectionsListRequest.__name__
 
-    async def handle(self, request: CollectionsList) -> Type[Response]:
+    async def handle(self, request: CollectionsListRequest) -> Type[Response]:
         format_links = self.get_links_for_self(request)
         if request.format == ResponseFormat.html:
             collections = [
diff --git a/oaff/app/oaff/app/request_handlers/conformance.py b/oaff/app/oaff/app/request_handlers/conformance.py
index 32750d9..1f7b406 100644
--- a/oaff/app/oaff/app/request_handlers/conformance.py
+++ b/oaff/app/oaff/app/request_handlers/conformance.py
@@ -1,18 +1,18 @@
 from typing import Type
 
 from oaff.app.request_handlers.common.request_handler import RequestHandler
-from oaff.app.requests.conformance import Conformance
+from oaff.app.requests.conformance import Conformance as ConformanceRequest
 from oaff.app.responses.models.conformance import ConformanceHtml, ConformanceJson
 from oaff.app.responses.response import Response
 from oaff.app.responses.response_format import ResponseFormat
 
 
-class Conformance(RequestHandler):
+class ConformanceRequestHandler(RequestHandler):
     @classmethod
     def type_name(cls) -> str:
-        return Conformance.__name__
+        return ConformanceRequest.__name__
 
-    async def handle(self, request: Conformance) -> Type[Response]:
+    async def handle(self, request: ConformanceRequest) -> Type[Response]:
         conform_list = [
             "http://www.opengis.net/spec/ogcapi-common-1/1.0/conf/core",
             "http://www.opengis.net/spec/ogcapi-common-2/1.0/conf/collections",
diff --git a/oaff/app/oaff/app/request_handlers/landing_page.py b/oaff/app/oaff/app/request_handlers/landing_page.py
index 8138892..3080347 100644
--- a/oaff/app/oaff/app/request_handlers/landing_page.py
+++ b/oaff/app/oaff/app/request_handlers/landing_page.py
@@ -3,7 +3,7 @@
 from oaff.app.configuration.frontend_interface import get_frontend_configuration
 from oaff.app.i18n.translations import gettext_for_locale
 from oaff.app.request_handlers.common.request_handler import RequestHandler
-from oaff.app.requests.landing_page import LandingPage
+from oaff.app.requests.landing_page import LandingPage as LandingPageRequest
 from oaff.app.responses.models.landing import LandingHtml, LandingJson
 from oaff.app.responses.models.link import Link, LinkRel
 from oaff.app.responses.response import Response
@@ -12,12 +12,12 @@
 from oaff.app.settings import OPENAPI_OGC_TYPE
 
 
-class LandingPage(RequestHandler):
+class LandingPageRequestHandler(RequestHandler):
     @classmethod
     def type_name(cls) -> str:
-        return LandingPage.__name__
+        return LandingPageRequest.__name__
 
-    async def handle(self, request: LandingPage) -> Type[Response]:
+    async def handle(self, request: LandingPageRequest) -> Type[Response]:
         gettext = gettext_for_locale(request.locale)
         frontend = get_frontend_configuration()
         title = gettext("Features API Landing Page")
diff --git a/oaff/app/oaff/app/responses/response_format.py b/oaff/app/oaff/app/responses/response_format.py
index 0a34fd8..34f954a 100644
--- a/oaff/app/oaff/app/responses/response_format.py
+++ b/oaff/app/oaff/app/responses/response_format.py
@@ -3,7 +3,7 @@
 from oaff.app.responses.response_type import ResponseType
 
 
-class ResponseFormat(dict, Enum):
+class ResponseFormat(dict, Enum):  # type: ignore[misc]
     html = {
         ResponseType.DATA: "text/html",
         ResponseType.METADATA: "text/html",
diff --git a/oaff/app/oaff/app/responses/templates/templates.py b/oaff/app/oaff/app/responses/templates/templates.py
index c8f62ff..2fbbf2e 100644
--- a/oaff/app/oaff/app/responses/templates/templates.py
+++ b/oaff/app/oaff/app/responses/templates/templates.py
@@ -13,7 +13,7 @@ def get_rendered_html(template_name: str, data: object, locale: Locales) -> str:
         loader=PackageLoader("oaff.app", path.join("responses", "templates", "html")),
         autoescape=select_autoescape(["html"]),
     )
-    env.install_gettext_translations(get_translations_for_locale(locale))
+    env.install_gettext_translations(get_translations_for_locale(locale))  # type: ignore
     frontend_config = get_frontend_configuration()
     return env.get_template(f"{template_name}.jinja2").render(
         response=data,
diff --git a/oaff/fastapi/api/openapi/openapi.py b/oaff/fastapi/api/openapi/openapi.py
index cdd8567..7d2368d 100644
--- a/oaff/fastapi/api/openapi/openapi.py
+++ b/oaff/fastapi/api/openapi/openapi.py
@@ -1,10 +1,12 @@
+from typing import Callable
+
 from fastapi.applications import FastAPI
 from fastapi.requests import Request
 
 from oaff.fastapi.api.openapi.vnd_response import VndResponse
 
 
-def get_openapi_handler(app: FastAPI) -> VndResponse:
+def get_openapi_handler(app: FastAPI) -> Callable[[Request], VndResponse]:
     def handler(_: Request):
         # OpenAPI spec must be modified because FastAPI doesn't support
         # encoding style: https://github.com/tiangolo/fastapi/issues/283
diff --git a/oaff/fastapi/api/routes/collections.py b/oaff/fastapi/api/routes/collections.py
index 32509ed..327de74 100644
--- a/oaff/fastapi/api/routes/collections.py
+++ b/oaff/fastapi/api/routes/collections.py
@@ -1,22 +1,19 @@
 from datetime import datetime
 from logging import getLogger
-from typing import Final, Optional, Tuple, Union
+from typing import Final, Optional, Tuple, Union, cast
 from urllib.parse import quote
 
 import iso8601
 import pytz
-from fastapi import APIRouter, HTTPException
+from fastapi import APIRouter, HTTPException, Query
 from fastapi.param_functions import Depends
-from fastapi.params import Query
 from fastapi.requests import Request
 
 from oaff.app.requests.collection import Collection as CollectionRequestType
 from oaff.app.requests.collection_items import (
     CollectionItems as CollectionItemsRequestType,
 )
-from oaff.app.requests.collections_list import (
-    CollectionsList as CollectionsListRequestType,
-)
+from oaff.app.requests.collections_list import CollectionsList as CollectionsListRequest
 from oaff.app.requests.feature import Feature as FeatureRequestType
 from oaff.app.responses.response_type import ResponseType
 from oaff.fastapi.api import settings
@@ -42,7 +39,7 @@ async def get_collections_list(
 ):
     enforce_strict(request)
     return await delegate(
-        CollectionsListRequestType(
+        CollectionsListRequest(
             type=ResponseType.METADATA,
             format=common_parameters.format,
             locale=common_parameters.locale,
@@ -216,7 +213,7 @@ def parse_datetime(datetime_str: str) -> datetime:
             raise HTTPException(
                 status_code=400, detail="datetime start cannot be after end"
             )
-    return tuple(result)
+    return cast(Union[Tuple[datetime], Tuple[datetime, datetime]], tuple(result))
 
 
 def _get_safe_url(path_template: str, request: Request, root: str) -> str:
diff --git a/oaff/fastapi/api/routes/common/common_parameters.py b/oaff/fastapi/api/routes/common/common_parameters.py
index 06c1476..eeaac49 100644
--- a/oaff/fastapi/api/routes/common/common_parameters.py
+++ b/oaff/fastapi/api/routes/common/common_parameters.py
@@ -1,5 +1,5 @@
 from re import compile, search, sub
-from typing import Final, Optional, Set
+from typing import Final, List, Optional
 
 from fastapi import Header, Query
 from fastapi.requests import Request
@@ -66,7 +66,7 @@ async def populate(
         )
 
     @classmethod
-    def _header_options_by_preference(cls, header_value: str) -> Set[str]:
+    def _header_options_by_preference(cls, header_value: str) -> List[str]:
         options = list(
             filter(
                 lambda option: len(option) > 0,
diff --git a/oaff/fastapi/api/routes/common/parameter_control.py b/oaff/fastapi/api/routes/common/parameter_control.py
index 9898da1..a81d3a7 100644
--- a/oaff/fastapi/api/routes/common/parameter_control.py
+++ b/oaff/fastapi/api/routes/common/parameter_control.py
@@ -7,7 +7,8 @@
 from oaff.fastapi.api.routes.common.common_parameters import COMMON_QUERY_PARAMS
 
 
-def strict(request: Request, permitted: Optional[List[str]] = []) -> None:
+def strict(request: Request, permitted: Optional[List[str]] = None) -> None:
+    permitted = list() if permitted is None else permitted
     excessive = set(request.query_params.keys()).difference(
         set(permitted + COMMON_QUERY_PARAMS)
     )
diff --git a/oaff/fastapi/api/routes/conformance.py b/oaff/fastapi/api/routes/conformance.py
index 8d14721..01526a7 100644
--- a/oaff/fastapi/api/routes/conformance.py
+++ b/oaff/fastapi/api/routes/conformance.py
@@ -4,7 +4,7 @@
 from fastapi import APIRouter, Depends
 from fastapi.requests import Request
 
-from oaff.app.requests.conformance import Conformance as ConformanceRequestType
+from oaff.app.requests.conformance import Conformance as ConformanceRequest
 from oaff.app.responses.response_type import ResponseType
 from oaff.fastapi.api import settings
 from oaff.fastapi.api.delegator import delegate, get_default_handler
@@ -24,7 +24,7 @@ async def root(
 ):
     enforce_strict(request)
     return await delegate(
-        ConformanceRequestType(
+        ConformanceRequest(
             type=ResponseType.METADATA,
             format=common_parameters.format,
             url=str(request.url),
diff --git a/oaff/fastapi/api/routes/landing_page.py b/oaff/fastapi/api/routes/landing_page.py
index 9739141..5f1be71 100644
--- a/oaff/fastapi/api/routes/landing_page.py
+++ b/oaff/fastapi/api/routes/landing_page.py
@@ -4,7 +4,7 @@
 from fastapi import APIRouter, Depends
 from fastapi.requests import Request
 
-from oaff.app.requests.landing_page import LandingPage as LandingPageRequestType
+from oaff.app.requests.landing_page import LandingPage as LandingPageRequest
 from oaff.app.responses.response_type import ResponseType
 from oaff.fastapi.api import settings
 from oaff.fastapi.api.delegator import delegate, get_default_handler
@@ -24,7 +24,7 @@ async def root(
 ):
     enforce_strict(request)
     return await delegate(
-        LandingPageRequestType(
+        LandingPageRequest(
             type=ResponseType.METADATA,
             format=common_parameters.format,
             url=str(request.url),
diff --git a/oaff/fastapi/api/util.py b/oaff/fastapi/api/util.py
index 0bc820b..52c3ee2 100644
--- a/oaff/fastapi/api/util.py
+++ b/oaff/fastapi/api/util.py
@@ -57,8 +57,8 @@ def _change_page(url: str, forward: bool) -> str:
                 for key, value in {
                     **parameters,
                     **{
-                        "offset": max(offset + limit * (1 if forward else -1), 0),
-                        "limit": limit,
+                        "offset": str(max(offset + limit * (1 if forward else -1), 0)),
+                        "limit": str(limit),
                     },
                 }.items()
             ]
diff --git a/oaff/fastapi/gunicorn/gunicorn.conf.py b/oaff/fastapi/gunicorn/gunicorn.conf.py
index b938fc0..c2eb6ec 100644
--- a/oaff/fastapi/gunicorn/gunicorn.conf.py
+++ b/oaff/fastapi/gunicorn/gunicorn.conf.py
@@ -2,7 +2,7 @@
 
 cpu_limit = os.environ.get("API_CPU_LIMIT")
 if cpu_limit is None:
-    num_avail_cpus = len(os.sched_getaffinity(0))
+    num_avail_cpus = len(os.sched_getaffinity(0))  # type: ignore[attr-defined]
 else:
     try:
         num_avail_cpus = int(cpu_limit)
diff --git a/oaff/fastapi/tests/test_conformance_delegation.py b/oaff/fastapi/tests/test_conformance_delegation.py
index 224e07f..00414d8 100644
--- a/oaff/fastapi/tests/test_conformance_delegation.py
+++ b/oaff/fastapi/tests/test_conformance_delegation.py
@@ -1,6 +1,6 @@
 from typing import Final
 
-from oaff.app.requests.conformance import Conformance
+from oaff.app.requests.conformance import Conformance as ConformanceRequest
 from oaff.fastapi.api.routes.conformance import PATH as ROOT_PATH
 from oaff.fastapi.tests import common_delegation as common
 
@@ -24,7 +24,7 @@ def test_basic_defaults(test_app):
     common.test_basic_defaults(
         test_app,
         endpoint_path,
-        Conformance,
+        ConformanceRequest,
         handler_calls,
     )
 
diff --git a/oaff/fastapi/tests/test_landing_delegation.py b/oaff/fastapi/tests/test_landing_delegation.py
index 401b68d..0a94850 100644
--- a/oaff/fastapi/tests/test_landing_delegation.py
+++ b/oaff/fastapi/tests/test_landing_delegation.py
@@ -1,6 +1,6 @@
 from typing import Final
 
-from oaff.app.requests.landing_page import LandingPage
+from oaff.app.requests.landing_page import LandingPage as LandingPageRequest
 from oaff.fastapi.api.routes.landing_page import PATH as ROOT_PATH
 from oaff.fastapi.tests import common_delegation as common
 
@@ -24,7 +24,7 @@ def test_basic_defaults(test_app):
     common.test_basic_defaults(
         test_app,
         endpoint_path,
-        LandingPage,
+        LandingPageRequest,
         handler_calls,
     )
 
diff --git a/pyproject.toml b/pyproject.toml
index 70b6854..e3420a0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -34,10 +34,11 @@ sections='FUTURE,STDLIB,THIRDPARTY,FIRSTPARTY,LOCALFOLDER'
 no_lines_before='LOCALFOLDER'
 
 [tool.mypy]
-exclude="^(tests|testing)$"
+exclude="^(tests|testing|data|scripts)$"
 namespace_packages=true
 explicit_package_bases=true
 ignore_missing_imports=true
-ignore_errors=true
 install_types=true
-non_interactive=true
\ No newline at end of file
+non_interactive=true
+no_warn_no_return=true
+no_strict_optional=true