diff --git a/tests/test_materialsproject.py b/tests/test_materialsproject.py
new file mode 100644
index 000000000..dd15f6b17
--- /dev/null
+++ b/tests/test_materialsproject.py
@@ -0,0 +1,65 @@
+import unittest
+from unittest.mock import MagicMock, patch
+import sys
+
+# Mock mp_api before importing structuretoolkit
+mock_mp_api = MagicMock()
+sys.modules["mp_api"] = mock_mp_api
+sys.modules["mp_api.client"] = mock_mp_api.client
+
+import structuretoolkit as stk
+
+class TestMaterialsProject(unittest.TestCase):
+    @patch("mp_api.client.MPRester")
+    @patch("structuretoolkit.build.materialsproject.pymatgen_to_ase")
+    def test_search(self, mock_pymatgen_to_ase, mock_mp_rester):
+        # Setup mock for MPRester as a context manager
+        mock_mpr = MagicMock()
+        mock_mp_rester.return_value.__enter__.return_value = mock_mpr
+
+        # Setup mock for summary.search
+        mock_mpr.summary.search.return_value = [
+            {"material_id": "mp-1", "structure": "mock_pmg_struct"}
+        ]
+
+        # Setup mock for pymatgen_to_ase
+        mock_pymatgen_to_ase.return_value = "mock_ase_struct"
+
+        # Call search
+        results = list(stk.build.materialsproject_search("Fe"))
+
+        # Assertions
+        self.assertEqual(len(results), 1)
+        self.assertEqual(results[0]["material_id"], "mp-1")
+        self.assertEqual(results[0]["structure"], "mock_ase_struct")
+        mock_mpr.summary.search.assert_called_once()
+        mock_pymatgen_to_ase.assert_called_once_with("mock_pmg_struct")
+
+    @patch("mp_api.client.MPRester")
+    @patch("structuretoolkit.build.materialsproject.pymatgen_to_ase")
+    def test_by_id(self, mock_pymatgen_to_ase, mock_mp_rester):
+        # Setup mock for MPRester as a context manager
+        mock_mpr = MagicMock()
+        mock_mp_rester.return_value.__enter__.return_value = mock_mpr
+
+        # Setup mock for pymatgen_to_ase
+        mock_pymatgen_to_ase.side_effect = lambda x: f"ase_{x}"
+
+        # Test final=True
+        mock_mpr.get_structure_by_material_id.return_value = "pmg_struct"
+        res = stk.build.materialsproject_by_id("mp-1", final=True)
+        self.assertEqual(res, "ase_pmg_struct")
+        mock_mpr.get_structure_by_material_id.assert_called_with(
+            material_id="mp-1", final=True, conventional_unit_cell=False
+        )
+
+        # Test final=False
+        mock_mpr.get_structure_by_material_id.return_value = ["pmg_1", "pmg_2"]
+        res = stk.build.materialsproject_by_id("mp-1", final=False)
+        self.assertEqual(res, ["ase_pmg_1", "ase_pmg_2"])
+        mock_mpr.get_structure_by_material_id.assert_called_with(
+            material_id="mp-1", final=False, conventional_unit_cell=False
+        )
+
+if __name__ == "__main__":
+    unittest.main()