diff --git a/Makefile b/Makefile
index b9bbbb3..cd06c58 100644
--- a/Makefile
+++ b/Makefile
@@ -30,7 +30,7 @@ format: .uv
 lint: .uv
 	uv run ruff format --check $(sources)
 	uv run ruff check $(sources)
-	uv run mypy $(sources)
+	uv run --group linting mypy $(sources)
 
 .PHONY: codespell  ## Use Codespell to do spellchecking
 codespell: .pre-commit
diff --git a/garth/data/__init__.py b/garth/data/__init__.py
index 2200687..3928873 100644
--- a/garth/data/__init__.py
+++ b/garth/data/__init__.py
@@ -1,4 +1,5 @@
-__all__ = ["HRVData", "SleepData"]
+__all__ = ["Activity", "HRVData", "SleepData"]
 
+from .activity import Activity
 from .hrv import HRVData
 from .sleep import SleepData
diff --git a/garth/data/activity.py b/garth/data/activity.py
new file mode 100644
index 0000000..cf48077
--- /dev/null
+++ b/garth/data/activity.py
@@ -0,0 +1,117 @@
+from datetime import datetime, timezone
+
+from pydantic.dataclasses import dataclass
+
+from .. import http
+from ..utils import camel_to_snake_dict, remove_dto_from_dict
+
+
+@dataclass(frozen=True)
+class ActivityType:
+    type_id: int
+    type_key: str
+    parent_type_id: int | None = None
+
+
+@dataclass(frozen=True)
+class Summary:
+    distance: float
+    duration: float
+    moving_duration: float
+    average_speed: float
+    max_speed: float
+    calories: float
+    average_hr: float
+    max_hr: float
+    start_time_gmt: datetime
+    start_time_local: datetime
+    start_latitude: float
+    start_longitude: float
+    elapsed_duration: float
+    elevation_gain: float
+    elevation_loss: float
+    max_elevation: float
+    min_elevation: float
+    average_moving_speed: float
+    bmr_calories: float
+    average_run_cadence: float
+    max_run_cadence: float
+    average_temperature: float
+    max_temperature: float
+    min_temperature: float
+    average_power: float
+    max_power: float
+    min_power: float
+    normalized_power: float
+    total_work: float
+    ground_contact_time: float
+    stride_length: float
+    vertical_oscillation: float
+    training_effect: float
+    anaerobic_training_effect: float
+    aerobic_training_effect_message: str
+    anaerobic_training_effect_message: str
+    vertical_ratio: float
+    end_latitude: float
+    end_longitude: float
+    max_vertical_speed: float
+    water_estimated: float
+    training_effect_label: str
+    activity_training_load: float
+    min_activity_lap_duration: float
+    moderate_intensity_minutes: float
+    vigorous_intensity_minutes: float
+    steps: int
+    begin_potential_stamina: float
+    end_potential_stamina: float
+    min_available_stamina: float
+    avg_grade_adjusted_speed: float
+    difference_body_battery: float
+
+
+@dataclass(frozen=True)
+class Activity:
+    activity_id: int
+    activity_name: str
+    activity_type: ActivityType
+    summary: Summary
+    average_running_cadence_in_steps_per_minute: float | None = None
+    max_running_cadence_in_steps_per_minute: float | None = None
+    steps: int | None = None
+
+    def _get_localized_datetime(
+        self, gmt_time: datetime, local_time: datetime
+    ) -> datetime:
+        local_diff = local_time - gmt_time
+        local_offset = timezone(local_diff)
+        gmt_time = datetime.fromtimestamp(
+            gmt_time.timestamp() / 1000, timezone.utc
+        )
+        return gmt_time.astimezone(local_offset)
+
+    @property
+    def activity_start(self) -> datetime:
+        return self._get_localized_datetime(
+            self.summary.start_time_gmt, self.summary.start_time_local
+        )
+
+    @classmethod
+    def get(
+        cls,
+        id: int,
+        *,
+        client: http.Client | None = None,
+    ):
+        client = client or http.client
+        path = f"/activity-service/activity/{id}"
+        activity_data = client.connectapi(path)
+        assert activity_data
+        activity_data = camel_to_snake_dict(activity_data)
+        activity_data = remove_dto_from_dict(activity_data)
+        assert isinstance(activity_data, dict)
+        return cls(**activity_data)
+
+    @classmethod
+    def list(cls, *args, **kwargs):
+        data = super().list(*args, **kwargs)
+        return sorted(data, key=lambda x: x.activity_start)
diff --git a/garth/utils.py b/garth/utils.py
index b00c62e..d30857e 100644
--- a/garth/utils.py
+++ b/garth/utils.py
@@ -33,6 +33,35 @@ def camel_to_snake_dict(camel_dict: Dict[str, Any]) -> Dict[str, Any]:
     return snake_dict
 
 
+def remove_dto(key: str) -> str:
+    if key.endswith("_dto"):
+        return key[: -len("_dto")]
+    elif key.endswith("DTO"):
+        return key[: -len("DTO")]
+    else:
+        return key
+
+
+def remove_dto_from_dict(input_dict: Dict[str, Any]) -> Dict[str, Any]:
+    """
+    Removes `DTO` suffix from dictionary keys. Different API endpoints give
+    back different key names, e.g. "activityTypeDTO" instead of "activityType".
+    """
+    output_dict: Dict[str, Any] = {}
+    for k, v in input_dict.items():
+        new_key = remove_dto(k)
+        if isinstance(v, dict):
+            output_dict[new_key] = remove_dto_from_dict(v)
+        elif isinstance(v, list):
+            output_dict[new_key] = [
+                remove_dto_from_dict(i) if isinstance(i, dict) else i
+                for i in v
+            ]
+        else:
+            output_dict[new_key] = v
+    return output_dict
+
+
 def format_end_date(end: Union[date, str, None]) -> date:
     if end is None:
         end = date.today()
diff --git a/pyproject.toml b/pyproject.toml
index e484dc9..d912889 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -74,6 +74,13 @@ indent-style = "space"
 skip-magic-trailing-comma = false
 line-ending = "auto"
 
+[dependency-groups]
+linting = [
+    "mypy>=1.13.0",
+    "ruff>=0.8.2",
+    "types-requests>=2.32.0.20241016",
+]
+
 [tool.ruff.lint.isort]
 known-first-party = ["garth"]
 combine-as-imports = true