diff --git a/native/src/main/java/org/humemai/nativelib/NativeExtras.java b/native/src/main/java/org/humemai/nativelib/NativeExtras.java
index 4b4872fe..7ee05e9d 100644
--- a/native/src/main/java/org/humemai/nativelib/NativeExtras.java
+++ b/native/src/main/java/org/humemai/nativelib/NativeExtras.java
@@ -315,8 +315,9 @@ private static String q(final String text) {
   }
 
   /**
-   * ops: metadata {type, prop} | approximate {type, prop, vector, k, allowed}. The index is the one the type has on the property; its bucket
-   * indexes are searched in turn (the caller merges). metadata describes the first bucket index, as the JPype wrapper does.
+   * ops: metadata {type, prop} | approximate {type, prop, vector, k, allowed} | build {type, prop}. The index is the one the type has on the
+   * property; its bucket indexes are searched in turn (the caller merges). metadata describes the first bucket index, as the JPype wrapper does.
+   * build rebuilds the graph of every bucket index now (buildVectorGraphNow), as the JPype wrapper's build_graph_now() does (#162).
    */
   @CEntryPoint(name = "arcadedb_n_vindex")
   @SuppressWarnings("unchecked")
@@ -383,6 +384,10 @@ public static CCharPointer vindex(final IsolateThread thread, final long dbh, fi
         }
         sb.append(']');
       }
+      case "build" -> {
+        for (final LSMVectorIndex lsm : parts)
+          lsm.buildVectorGraphNow();
+      }
       default -> throw new IllegalArgumentException("unknown vector index op " + ArcadeNative.str(op));
       }
       return ArcadeNative.out(sb.append('}').toString());
diff --git a/src/arcadedb/_native/schema_objects.py b/src/arcadedb/_native/schema_objects.py
index 52a85e79..ceb647a8 100644
--- a/src/arcadedb/_native/schema_objects.py
+++ b/src/arcadedb/_native/schema_objects.py
@@ -136,17 +136,27 @@ def countEntries(self):
         return int(row.get("c"))
 
     def warmUp(self):
-        # the engine loads a persisted graph on the first search: run that search now
-        self.buildVectorGraphNow()
-
-    def buildVectorGraphNow(self):
-        # the engine builds the graph on the first search: one search now, on a vector of the index's dimension
+        # the engine loads a persisted graph on the first search: one search now, on a vector of the index's dimension
         dims = self.engine_info()["dimensions"]
         if dims:
             self._db.query(
                 "sql", "SELECT vectorNeighbors(?, ?, 1)", self._name, [1.0] * dims
             ).close()
 
+    def buildVectorGraphNow(self):
+        # the engine's own rebuild of every bucket index (LSMVectorIndex.buildVectorGraphNow), as the JPype wrapper calls it:
+        # a search builds a graph only when there is none, so it left the vectors written since in the delta (#162)
+        from . import lib
+        from .extras import _call, _enc
+
+        _call(
+            "Failed to rebuild vector graph",
+            "arcadedb_n_vindex",
+            self._db._h,
+            lib.b("build"),
+            lib.b(_enc({"type": self._type, "prop": self._prop})),
+        )
+
 
 def _rid_text(value) -> str:
     get_rid = getattr(value, "get_rid", None)
diff --git a/tests/test_vector_index_introspection.py b/tests/test_vector_index_introspection.py
index d3083b2a..4a6631ea 100644
--- a/tests/test_vector_index_introspection.py
+++ b/tests/test_vector_index_introspection.py
@@ -283,6 +283,44 @@ def test_alter_database_sets_the_ratio_the_threshold_reads(self, temp_db):
         assert index.get_stats()["effectiveMutationsThreshold"] == 500
 
 
+class TestBuildGraphNow:
+    """``build_graph_now()`` rebuilds a graph that already exists, so the vectors written since it was built join it (#162).
+
+    The native build ran one search, which builds a graph only when there is none: on a built index the call returned at
+    once and the new vectors stayed in the delta. The automatic triggers are off (a high floor, no inactivity timer), so
+    only the call can move the counters. The graph starts at 1000 vectors because the engine rebuilds a smaller one
+    synchronously on the next search (ASYNC_REBUILD_MIN_GRAPH_SIZE), which hid the defect.
+    """
+
+    ROWS = [
+        (f"v{i}", [1.0 + i % 10, 1.0 + i // 10 % 10, 1.0 + i // 100])
+        for i in range(1100)
+    ]
+
+    def test_rebuilds_an_existing_graph(self, temp_db):
+        _make_type(temp_db)
+        temp_db.command(
+            "sql",
+            "ALTER DATABASE `arcadedb.vectorIndex.inactivityRebuildTimeoutMs` 0",
+        )
+        _insert(temp_db, self.ROWS[:1000])
+        index = temp_db.create_vector_index(
+            "Doc", "embedding", dimensions=3, mutations_before_rebuild=1_000_000
+        )
+        before = index.get_stats()
+        assert before["graphNodeCount"] == 1000
+
+        _insert(temp_db, self.ROWS[1000:])
+        assert index.get_stats()["graphNodeCount"] == 1000
+
+        index.build_graph_now()
+
+        after = index.get_stats()
+        assert after["totalVectors"] == len(self.ROWS)
+        assert after["graphNodeCount"] == len(self.ROWS)
+        assert after["graphRebuildCount"] > before["graphRebuildCount"]
+
+
 class TestWrapperAcrossRebuildAndDrop:
     """A ``VectorIndex`` held across SQL ``REBUILD INDEX`` keeps serving; across a drop it raises (#116).