diff --git a/app/ml/__init__.py b/app/ml/__init__.py
new file mode 100644
index 0000000..1a48763
--- /dev/null
+++ b/app/ml/__init__.py
@@ -0,0 +1,5 @@
+"""Machine-Learning-Grundbausteine für SillyHome Next."""
+
+from app.ml.feature_store import FeatureStore, FeatureVector
+
+__all__ = ["FeatureStore", "FeatureVector"]
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diff --git a/app/ml/feature_store.py b/app/ml/feature_store.py
new file mode 100644
index 0000000..9e2540d
--- /dev/null
+++ b/app/ml/feature_store.py
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+from __future__ import annotations
+
+from collections import defaultdict
+from dataclasses import dataclass, field
+from typing import Iterable
+
+
+@dataclass(frozen=True)
+class FeatureVector:
+    sensor_id: str
+    values: dict[str, float]
+    label: str | None = None
+
+
+class FeatureStore:
+    def __init__(self) -> None:
+        self._vectors: dict[str, list[FeatureVector]] = defaultdict(list)
+
+    def add(self, vector: FeatureVector) -> None:
+        self._vectors[vector.sensor_id].append(vector)
+
+    def add_batch(self, vectors: Iterable[FeatureVector]) -> None:
+        for vector in vectors:
+            self.add(vector)
+
+    def latest(self, sensor_id: str) -> FeatureVector | None:
+        series = self._vectors.get(sensor_id)
+        return series[-1] if series else None
+
+    def all(self) -> list[FeatureVector]:
+        return [vector for vectors in self._vectors.values() for vector in vectors]
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diff --git a/tests/ml/test_feature_store.py b/tests/ml/test_feature_store.py
new file mode 100644
index 0000000..2d881ea
--- /dev/null
+++ b/tests/ml/test_feature_store.py
@@ -0,0 +1,42 @@
+from __future__ import annotations
+
+import pytest
+
+from app.ml.feature_store import FeatureStore, FeatureVector
+
+
+def _vector(sensor_id: str, temperature: float, label: str | None = None) -> FeatureVector:
+    return FeatureVector(sensor_id=sensor_id, values={"temperature": temperature}, label=label)
+
+
+def test_append_and_latest_returns_last_vector() -> None:
+    store = FeatureStore()
+    vectors = [_vector("sensor.living_room", 20.0), _vector("sensor.living_room", 21.5)]
+    for item in vectors:
+        store.add(item)
+    assert store.latest("sensor.living_room") == vectors[-1]
+
+
+def test_latest_returns_none_when_empty() -> None:
+    store = FeatureStore()
+    assert store.latest("sensor.living_room") is None
+
+
+def test_add_batch_appends_all_vectors() -> None:
+    store = FeatureStore()
+    vectors = [
+        _vector("sensor.kitchen", 19.0),
+        _vector("sensor.kitchen", 20.0),
+        _vector("sensor.bathroom", 23.5),
+    ]
+    store.add_batch(vectors)
+    assert len(store.all()) == 3
+    assert store.latest("sensor.kitchen").values["temperature"] == 20.0
+
+
+def test_different_sensors_are_stored_independently() -> None:
+    store = FeatureStore()
+    store.add(_vector("sensor.living_room", 21.0))
+    store.add(_vector("sensor.bedroom", 18.5))
+    assert store.latest("sensor.living_room").values["temperature"] == 21.0
+    assert store.latest("sensor.bedroom").values["temperature"] == 18.5
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