diff --git a/edge/zones.py b/edge/zones.py
new file mode 100644
index 0000000..91af6f2
--- /dev/null
+++ b/edge/zones.py
@@ -0,0 +1,23 @@
+import json
+
+from edge.detectors.zone import Zone
+
+
+def zones_from_config(config: dict) -> list[Zone]:
+    out: list[Zone] = []
+    for row in config.get("zones", []) or []:
+        try:
+            raw = row["polygon_json"]
+            pts = json.loads(raw) if isinstance(raw, str) else raw
+            polygon = [(float(p[0]), float(p[1])) for p in pts]
+            if len(polygon) < 3:
+                continue
+            out.append(Zone(str(row["zone_id"]), str(row["level"]), polygon))
+        except (KeyError, ValueError, TypeError, json.JSONDecodeError):
+            continue
+    return out
+
+
+def thresholds_from_config(config: dict) -> dict:
+    t = config.get("thresholds")
+    return t if isinstance(t, dict) else {}
diff --git a/tests/test_zones.py b/tests/test_zones.py
new file mode 100644
index 0000000..67f015b
--- /dev/null
+++ b/tests/test_zones.py
@@ -0,0 +1,21 @@
+from edge.zones import zones_from_config, thresholds_from_config
+
+def test_parses_zone_rows_json_string_polygon():
+    cfg = {"zones": [
+        {"zone_id": "z1", "camera_id": "cam-1", "level": "restricted",
+         "polygon_json": "[[0,0],[9,0],[9,9]]"},
+    ], "thresholds": {"fall_prone_s": 3.0}}
+    zones = zones_from_config(cfg)
+    assert len(zones) == 1
+    assert zones[0].zone_id == "z1"
+    assert zones[0].level == "restricted"
+    assert zones[0].polygon == [(0.0, 0.0), (9.0, 0.0), (9.0, 9.0)]
+    assert thresholds_from_config(cfg)["fall_prone_s"] == 3.0
+
+def test_skips_malformed_row():
+    cfg = {"zones": [{"zone_id": "bad"}], "thresholds": {}}
+    assert zones_from_config(cfg) == []
+
+def test_empty_config():
+    assert zones_from_config({}) == []
+    assert thresholds_from_config({}) == {}