diff --git a/README.md b/README.md
index 440bd83..3885e6d 100644
--- a/README.md
+++ b/README.md
@@ -142,13 +142,15 @@ for document in documents.documents:
 print(documents.pagination.total_pages)
 ```
 
-Retrieval supports exclusions when clients want follow-up results that avoid
-previously used documents or sections:
+Retrieval can limit documents for one request and exclude documents or sections.
+Omitting `include_document_ids` leaves documents unrestricted by inclusion;
+passing `[]` matches no documents. Exclusions take precedence over inclusions.
 
 ```python
 response = client.retrieval.query(
     namespace="support-center",
     query="battery charging",
+    include_document_ids=["doc_123", "doc_old"],
     exclude_document_ids=["doc_old"],
     exclude_sections=[
         {"document_id": "doc_123", "section_path": "Appendix / Legal"}
diff --git a/docs/usage.md b/docs/usage.md
index 8b60424..d78e8a2 100644
--- a/docs/usage.md
+++ b/docs/usage.md
@@ -585,15 +585,18 @@ result.source.source_file_name
 result.source.section_path
 ```
 
-### Exclude documents or sections
+### Limit or exclude documents or sections
 
-Use exclusions for follow-up queries that should avoid already-used context.
+Use `include_document_ids` to search only the supplied documents for this
+request. Omit it to leave documents unrestricted by inclusion; pass `[]` to
+match no documents. Exclusions take precedence over inclusions.
 
 ```python
 response = client.retrieval.query(
     namespace="support-center",
     query="battery charging",
     top_k=10,
+    include_document_ids=["doc_123", "doc_old"],
     exclude_document_ids=["doc_old"],
     exclude_sections=[
         {"document_id": "doc_123", "section_path": "Appendix / Legal"}
diff --git a/src/knowhere/resources/retrieval.py b/src/knowhere/resources/retrieval.py
index 6061edf..2ce427e 100644
--- a/src/knowhere/resources/retrieval.py
+++ b/src/knowhere/resources/retrieval.py
@@ -34,6 +34,7 @@ def query(
         rerank: Optional[bool] = None,
         threshold: Optional[float] = None,
         internal_recall_k: Optional[int] = None,
+        include_document_ids: Optional[list[str]] = None,
         exclude_document_ids: Optional[list[str]] = None,
         exclude_sections: Optional[list[RetrievalSectionExclusion]] = None,
         llm_config: Optional[LLMConfig] = None,
@@ -64,6 +65,8 @@ def query(
             body["threshold"] = threshold
         if internal_recall_k is not None:
             body["internal_recall_k"] = internal_recall_k
+        if include_document_ids is not None:
+            body["include_document_ids"] = include_document_ids
         if exclude_document_ids is not None:
             body["exclude_document_ids"] = exclude_document_ids
         if exclude_sections is not None:
@@ -98,6 +101,7 @@ async def query(
         rerank: Optional[bool] = None,
         threshold: Optional[float] = None,
         internal_recall_k: Optional[int] = None,
+        include_document_ids: Optional[list[str]] = None,
         exclude_document_ids: Optional[list[str]] = None,
         exclude_sections: Optional[list[RetrievalSectionExclusion]] = None,
         llm_config: Optional[LLMConfig] = None,
@@ -128,6 +132,8 @@ async def query(
             body["threshold"] = threshold
         if internal_recall_k is not None:
             body["internal_recall_k"] = internal_recall_k
+        if include_document_ids is not None:
+            body["include_document_ids"] = include_document_ids
         if exclude_document_ids is not None:
             body["exclude_document_ids"] = exclude_document_ids
         if exclude_sections is not None:
diff --git a/tests/test_retrieval.py b/tests/test_retrieval.py
index 6529626..515fb3b 100644
--- a/tests/test_retrieval.py
+++ b/tests/test_retrieval.py
@@ -105,6 +105,7 @@ def test_query_sends_request_and_returns_results(self, sync_client: Any) -> None
             rerank=True,
             threshold=0.2,
             internal_recall_k=25,
+            include_document_ids=["doc_123", "doc_old"],
             exclude_document_ids=["doc_old"],
             exclude_sections=[
                 {
@@ -128,6 +129,7 @@ def test_query_sends_request_and_returns_results(self, sync_client: Any) -> None
             "rerank": True,
             "threshold": 0.2,
             "internal_recall_k": 25,
+            "include_document_ids": ["doc_123", "doc_old"],
             "exclude_document_ids": ["doc_old"],
             "exclude_sections": [
                 {
@@ -239,6 +241,27 @@ def test_query_omits_defaulted_optional_fields(self, sync_client: Any) -> None:
 
         request_body: Dict[str, Any] = json.loads(route.calls[0].request.read())
         assert request_body == {"query": "refund policy"}
+        assert "include_document_ids" not in request_body
+        assert "exclude_document_ids" not in request_body
+
+    @respx.mock
+    def test_query_preserves_empty_document_scope_arrays(self, sync_client: Any) -> None:
+        route = respx.post(RETRIEVAL_QUERY_URL).mock(
+            return_value=httpx.Response(200, json=_make_retrieval_response())
+        )
+
+        sync_client.retrieval.query(
+            query="refund policy",
+            include_document_ids=[],
+            exclude_document_ids=[],
+        )
+
+        request_body: Dict[str, Any] = json.loads(route.calls[0].request.read())
+        assert request_body == {
+            "query": "refund policy",
+            "include_document_ids": [],
+            "exclude_document_ids": [],
+        }
 
     @respx.mock
     @pytest.mark.asyncio