🔖 Release version 0.140.4 (#16070)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

docs/en/docs/release-notes.md

@@ -7,6 +7,18 @@ hide:
 
 ## Latest Changes
 
+## 0.140.4 (2026-07-27)
+
+### Refactors
+
+* ⚡️ Skip unused dependency repeat bookkeeping. PR [#16069](https://github.com/fastapi/fastapi/pull/16069) by [@tiangolo](https://github.com/tiangolo).
+
+## 0.140.3 (2026-07-27)
+
+### Refactors
+
+* ⚡️ Avoid repeated dependency flattening in OpenAPI. PR [#16067](https://github.com/fastapi/fastapi/pull/16067) by [@tiangolo](https://github.com/tiangolo).
+
 ## 0.140.2 (2026-07-27)
 
 ### Refactors

fastapi/__init__.py

@@ -1,6 +1,6 @@
 """FastAPI framework, high performance, easy to learn, fast to code, ready for production"""
 
-__version__ = "0.140.2"
+__version__ = "0.140.4"
 
 from starlette import status as status
 

fastapi/dependencies/utils.py

@@ -152,16 +152,20 @@ def get_flat_dependant(
     parent_oauth_scopes: list[str] | None = None,
     _uses_scopes_cache: _UsesScopesCache | None = None,
 ) -> Dependant:
-    if visited is None:
-        visited = []
-    if _uses_scopes_cache is None:
-        _uses_scopes_cache = {}
-    visited.append(
-        _get_cache_key(
-            dependant=dependant,
-            uses_scopes_cache=_uses_scopes_cache,
-        )
+    track_visited = (
+        skip_repeats or visited is not None or _uses_scopes_cache is not None
     )
+    if track_visited:
+        if visited is None:
+            visited = []
+        if _uses_scopes_cache is None:
+            _uses_scopes_cache = {}
+        visited.append(
+            _get_cache_key(
+                dependant=dependant,
+                uses_scopes_cache=_uses_scopes_cache,
+            )
+        )
     use_parent_oauth_scopes = (parent_oauth_scopes or []) + (
         _get_oauth_scopes(dependant=dependant)
     )
@@ -187,15 +191,16 @@ def get_flat_dependant(
         scope=dependant.scope,
     )
     for sub_dependant in dependant.dependencies:
-        if (
-            skip_repeats
-            and _get_cache_key(
-                dependant=sub_dependant,
-                uses_scopes_cache=_uses_scopes_cache,
-            )
-            in visited
-        ):
-            continue
+        if skip_repeats:
+            assert visited is not None
+            if (
+                _get_cache_key(
+                    dependant=sub_dependant,
+                    uses_scopes_cache=_uses_scopes_cache,
+                )
+                in visited
+            ):
+                continue
         flat_sub = get_flat_dependant(
             sub_dependant,
             skip_repeats=skip_repeats,

fastapi/openapi/utils.py

@@ -112,7 +112,7 @@ def get_openapi_security_definitions(
 
 def _get_openapi_operation_parameters(
     *,
-    dependant: Dependant,
+    flat_dependant: Dependant,
     model_name_map: ModelNameMap,
     field_mapping: dict[
         tuple[ModelField, Literal["validation", "serialization"]], dict[str, Any]
@@ -120,7 +120,6 @@ def _get_openapi_operation_parameters(
     separate_input_output_schemas: bool = True,
 ) -> list[dict[str, Any]]:
     parameters = []
-    flat_dependant = get_flat_dependant(dependant, skip_repeats=True)
     path_params = _get_flat_fields_from_params(flat_dependant.path_params)
     query_params = _get_flat_fields_from_params(flat_dependant.query_params)
     header_params = _get_flat_fields_from_params(flat_dependant.header_params)
@@ -284,12 +283,22 @@ def get_openapi_path(
     assert current_response_class, "A response class is needed to generate OpenAPI"
     route_response_media_type: str | None = current_response_class.media_type
     if route.include_in_schema:
+        flat_dependant = get_flat_dependant(route.dependant, skip_repeats=True)
+        all_route_params = [
+            field
+            for fields in (
+                flat_dependant.path_params,
+                flat_dependant.query_params,
+                flat_dependant.header_params,
+                flat_dependant.cookie_params,
+            )
+            for field in _get_flat_fields_from_params(fields)
+        ]
         for method in route.methods:
             operation = get_openapi_operation_metadata(
                 route=route, method=method, operation_ids=operation_ids
             )
             parameters: list[dict[str, Any]] = []
-            flat_dependant = get_flat_dependant(route.dependant, skip_repeats=True)
             security_definitions, operation_security = get_openapi_security_definitions(
                 flat_dependant=flat_dependant
             )
@@ -298,7 +307,7 @@ def get_openapi_path(
             if security_definitions:
                 security_schemes.update(security_definitions)
             operation_parameters = _get_openapi_operation_parameters(
-                dependant=route.dependant,
+                flat_dependant=flat_dependant,
                 model_name_map=model_name_map,
                 field_mapping=field_mapping,
                 separate_input_output_schemas=separate_input_output_schemas,
@@ -458,7 +467,6 @@ def get_openapi_path(
                     deep_dict_update(openapi_response, process_response)
                     openapi_response["description"] = description
             http422 = "422"
-            all_route_params = get_flat_params(route.dependant)
             if (all_route_params or route.body_field) and not any(
                 status in operation["responses"]
                 for status in [http422, "4XX", "default"]