diff --git a/spike_classifier/src/spike_classifier/core.py b/spike_classifier/src/spike_classifier/core.py
new file mode 100644
index 0000000..615842f
--- /dev/null
+++ b/spike_classifier/src/spike_classifier/core.py
@@ -0,0 +1,73 @@
+import json
+from datetime import datetime
+from statistics import mean
+
+
+def classify_spikes(json_data: dict) -> list[dict]:
+    """Analysiert und klassifiziert CPU-Spike-Events.
+
+    Args:
+        json_data (dict): JSON-Daten mit Spike-Events.
+
+    Returns:
+        list[dict]: Liste klassifizierter Spikes mit Kennwerten.
+    """
+    if not isinstance(json_data, dict) or 'spikes' not in json_data:
+        raise ValueError('Invalid input JSON: expected dict with key "spikes"')
+
+    classified = []
+    spikes = json_data.get('spikes', [])
+    if not isinstance(spikes, list):
+        raise ValueError('Invalid spikes format: expected list')
+
+    reorder_scores = []
+    for s in spikes:
+        score = s.get('reorder_score', 0.0)
+        if isinstance(score, (int, float)):
+            reorder_scores.append(score)
+
+    avg_score = mean(reorder_scores) if reorder_scores else 0.0
+
+    for event in spikes:
+        spike_id = str(event.get('spike_id', 'unknown'))
+        cpu_path = event.get('cpu_path', '')
+        reorder_score = float(event.get('reorder_score', 0.0))
+        timestamp_raw = event.get('timestamp')
+        signature = event.get('signature', '')
+
+        # Timestamps validieren und konvertieren
+        if isinstance(timestamp_raw, str):
+            try:
+                timestamp = datetime.fromisoformat(timestamp_raw)
+            except ValueError:
+                timestamp = datetime.utcnow()
+        elif isinstance(timestamp_raw, datetime):
+            timestamp = timestamp_raw
+        else:
+            timestamp = datetime.utcnow()
+
+        # Einfache Klassifikationslogik
+        if reorder_score > avg_score * 1.2:
+            classification = 'high_reorder'
+        elif reorder_score < avg_score * 0.8:
+            classification = 'low_reorder'
+        else:
+            classification = 'normal'
+
+        # Signaturanalyse (rudimentär)
+        if not signature and isinstance(cpu_path, str):
+            if ',' in cpu_path:
+                signature = 'multi_cpu'
+            else:
+                signature = 'single_cpu'
+
+        classified.append({
+            'spike_id': spike_id,
+            'cpu_path': cpu_path,
+            'reorder_score': reorder_score,
+            'timestamp': timestamp.isoformat(),
+            'signature': signature,
+            'classification': classification
+        })
+
+    return classified