Add Client.validate_key() helper

openrouteservice/client.py

@@ -103,6 +103,27 @@ def __init__(
         )
 
         self._req = None
+    def validate_key(self, profile="driving-car", coordinates=None) -> bool:
+        """
+        Validate the configured API key by performing a lightweight request.
+
+        Returns True if the key appears valid.
+        Raises openrouteservice.exceptions.ApiError for invalid keys or other API errors.
+        """
+        if coordinates is None:
+            # Two close points (small/cheap request)
+            coordinates = ((8.681495, 49.41461), (8.686507, 49.41943))
+
+        # Minimal directions request; invalid keys will raise ApiError from request()
+        self.request(
+            url=f"/v2/directions/{profile}",
+            post_json={
+                "coordinates": coordinates,
+                "instructions": False,
+                "geometry": False,
+            },
+        )
+        return True
 
     def request(
         self,

tests/client/test_validate_key.py

@@ -0,0 +1,22 @@
+import pytest
+from unittest.mock import patch
+
+import openrouteservice
+from openrouteservice.exceptions import ApiError
+
+
+def test_validate_key_success():
+    client = openrouteservice.Client(key="valid_key")
+
+    with patch.object(client, "request", return_value={"ok": True}) as mock_request:
+        result = client.validate_key()
+        assert result is True
+        mock_request.assert_called_once()
+
+
+def test_validate_key_invalid_key_raises():
+    client = openrouteservice.Client(key="invalid_key")
+
+    with patch.object(client, "request", side_effect=ApiError(403, "Forbidden")):
+        with pytest.raises(ApiError):
+            client.validate_key()