core: unify item metadata feature flag with legacy alias

codex-rs/core/config.schema.json

@@ -407,6 +407,9 @@
             "include_apply_patch_tool": {
               "type": "boolean"
             },
+            "item_metadata": {
+              "type": "boolean"
+            },
             "js_repl": {
               "type": "boolean"
             },
@@ -1962,6 +1965,9 @@
         "include_apply_patch_tool": {
           "type": "boolean"
         },
+        "item_metadata": {
+          "type": "boolean"
+        },
         "js_repl": {
           "type": "boolean"
         },

codex-rs/core/src/codex.rs

@@ -3787,7 +3787,7 @@ impl Session {
         response_item: ResponseItem,
         user_message_type: Option<UserMessageType>,
     ) {
-        let user_message_type = if self.enabled(Feature::UserMessageTypeMetadata) {
+        let user_message_type = if self.enabled(Feature::ItemMetadata) {
             user_message_type
         } else {
             None
@@ -3918,7 +3918,7 @@ impl Session {
         }
 
         let mut input_item: ResponseInputItem = input.into();
-        if self.enabled(Feature::UserMessageTypeMetadata) {
+        if self.enabled(Feature::ItemMetadata) {
             stamp_user_message_type_on_input_item(&mut input_item, UserMessageType::PromptSteering);
         }
 
@@ -3941,7 +3941,7 @@ impl Session {
                         ResponseInputItem::Message { .. } => Some(UserMessageType::PromptQueued),
                         _ => None,
                     };
-                    if self.enabled(Feature::UserMessageTypeMetadata)
+                    if self.enabled(Feature::ItemMetadata)
                         && let Some(kind) = user_message_type.clone()
                     {
                         stamp_user_message_type_on_input_item(&mut item, kind);
@@ -5726,7 +5726,7 @@ pub(crate) async fn run_turn(
         .await;
 
     let mut initial_input_for_turn: ResponseInputItem = ResponseInputItem::from(input.clone());
-    if sess.enabled(Feature::UserMessageTypeMetadata) {
+    if sess.enabled(Feature::ItemMetadata) {
         stamp_user_message_type_on_input_item(&mut initial_input_for_turn, UserMessageType::Prompt);
     }
     let response_item: ResponseItem = initial_input_for_turn.clone().into();

codex-rs/core/src/codex_tests.rs

@@ -3841,7 +3841,7 @@ async fn task_finish_emits_prompt_queued_metadata_for_injected_user_input_when_f
     Arc::get_mut(&mut sess)
         .expect("session should be uniquely owned in this test")
         .features
-        .enable(crate::features::Feature::UserMessageTypeMetadata)
+        .enable(crate::features::Feature::ItemMetadata)
         .expect("feature flag should be enabled for this test");
 
     let input = vec![UserInput::Text {

codex-rs/core/src/features.rs

@@ -174,8 +174,8 @@ pub enum Feature {
     ToolCallMcpElicitation,
     /// Enable personality selection in the TUI.
     Personality,
-    /// Emit user_message_type metadata on user message turn items and request items.
-    UserMessageTypeMetadata,
+    /// Emit item-level metadata on request/response items.
+    ItemMetadata,
     /// Enable native artifact tools.
     Artifact,
     /// Enable Fast mode selection in the TUI and request layer.
@@ -814,8 +814,8 @@ pub const FEATURES: &[FeatureSpec] = &[
         default_enabled: true,
     },
     FeatureSpec {
-        id: Feature::UserMessageTypeMetadata,
-        key: "user_message_type_metadata",
+        id: Feature::ItemMetadata,
+        key: "item_metadata",
         stage: Stage::UnderDevelopment,
         default_enabled: false,
     },

codex-rs/core/src/features/legacy.rs

@@ -45,6 +45,10 @@ const ALIASES: &[Alias] = &[
         legacy_key: "memory_tool",
         feature: Feature::MemoryTool,
     },
+    Alias {
+        legacy_key: "user_message_type_metadata",
+        feature: Feature::ItemMetadata,
+    },
 ];
 
 pub(crate) fn legacy_feature_keys() -> impl Iterator<Item = &'static str> {

codex-rs/core/src/features_tests.rs

@@ -142,6 +142,18 @@ fn collab_is_legacy_alias_for_multi_agent() {
     assert_eq!(feature_for_key("collab"), Some(Feature::Collab));
 }
 
+#[test]
+fn user_message_type_metadata_is_legacy_alias_for_item_metadata() {
+    assert_eq!(feature_for_key("user_message_type_metadata"), Some(Feature::ItemMetadata));
+    assert_eq!(feature_for_key("item_metadata"), Some(Feature::ItemMetadata));
+}
+
+#[test]
+fn item_metadata_is_under_development_and_disabled_by_default() {
+    assert_eq!(Feature::ItemMetadata.stage(), Stage::UnderDevelopment);
+    assert_eq!(Feature::ItemMetadata.default_enabled(), false);
+}
+
 #[test]
 fn multi_agent_is_stable_and_enabled_by_default() {
     assert_eq!(Feature::Collab.stage(), Stage::Stable);

codex-rs/core/tests/suite/items.rs

@@ -136,7 +136,7 @@ async fn user_message_type_metadata_is_emitted_when_feature_enabled() -> anyhow:
         .with_config(|config| {
             config
                 .features
-                .enable(Feature::UserMessageTypeMetadata)
+                .enable(Feature::ItemMetadata)
                 .expect("feature flag should be enabled for this test");
         })
         .build(&server)
@@ -259,7 +259,7 @@ async fn user_message_type_prompt_steering_metadata_is_emitted_when_feature_enab
         .with_config(|config| {
             config
                 .features
-                .enable(Feature::UserMessageTypeMetadata)
+                .enable(Feature::ItemMetadata)
                 .expect("feature flag should be enabled for this test");
         })
         .build(&server)
@@ -389,7 +389,7 @@ async fn user_message_type_prompt_queued_metadata_is_emitted_when_feature_enable
         .with_config(|config| {
             config
                 .features
-                .enable(Feature::UserMessageTypeMetadata)
+                .enable(Feature::ItemMetadata)
                 .expect("feature flag should be enabled for this test");
         })
         .build(&server)