diff --git a/codex-rs/app-server/src/config_api.rs b/codex-rs/app-server/src/config_api.rs
index 2be0bb859c..51f17b1162 100644
--- a/codex-rs/app-server/src/config_api.rs
+++ b/codex-rs/app-server/src/config_api.rs
@@ -43,6 +43,7 @@ use tracing::warn;
 const SUPPORTED_EXPERIMENTAL_FEATURE_ENABLEMENT: &[&str] = &[
     "apps",
     "plugins",
+    "selection_quote_replies",
     "tool_search",
     "tool_suggest",
     "tool_call_mcp_elicitation",
diff --git a/codex-rs/app-server/tests/suite/v2/experimental_feature_list.rs b/codex-rs/app-server/tests/suite/v2/experimental_feature_list.rs
index 3063830d5a..90d2c6d8b1 100644
--- a/codex-rs/app-server/tests/suite/v2/experimental_feature_list.rs
+++ b/codex-rs/app-server/tests/suite/v2/experimental_feature_list.rs
@@ -165,6 +165,7 @@ async fn experimental_feature_enablement_set_only_updates_named_features() -> Re
         &mut mcp,
         BTreeMap::from([
             ("plugins".to_string(), true),
+            ("selection_quote_replies".to_string(), true),
             ("tool_search".to_string(), true),
             ("tool_suggest".to_string(), true),
             ("tool_call_mcp_elicitation".to_string(), false),
@@ -177,6 +178,7 @@ async fn experimental_feature_enablement_set_only_updates_named_features() -> Re
         ExperimentalFeatureEnablementSetResponse {
             enablement: BTreeMap::from([
                 ("plugins".to_string(), true),
+                ("selection_quote_replies".to_string(), true),
                 ("tool_search".to_string(), true),
                 ("tool_suggest".to_string(), true),
                 ("tool_call_mcp_elicitation".to_string(), false),
@@ -200,6 +202,13 @@ async fn experimental_feature_enablement_set_only_updates_named_features() -> Re
             .and_then(|features| features.get("plugins")),
         Some(&json!(true))
     );
+    assert_eq!(
+        config
+            .additional
+            .get("features")
+            .and_then(|features| features.get("selection_quote_replies")),
+        Some(&json!(true))
+    );
     assert_eq!(
         config
             .additional
@@ -283,7 +292,9 @@ async fn experimental_feature_enablement_set_rejects_non_allowlisted_feature() -
     assert!(
         error
             .message
-            .contains("apps, plugins, tool_search, tool_suggest, tool_call_mcp_elicitation"),
+            .contains(
+                "apps, plugins, selection_quote_replies, tool_search, tool_suggest, tool_call_mcp_elicitation"
+            ),
         "{}",
         error.message
     );
diff --git a/codex-rs/core/config.schema.json b/codex-rs/core/config.schema.json
index 853f0235e0..adaf1f92d6 100644
--- a/codex-rs/core/config.schema.json
+++ b/codex-rs/core/config.schema.json
@@ -461,6 +461,9 @@
             "search_tool": {
               "type": "boolean"
             },
+            "selection_quote_replies": {
+              "type": "boolean"
+            },
             "shell_snapshot": {
               "type": "boolean"
             },
@@ -2074,6 +2077,9 @@
         "search_tool": {
           "type": "boolean"
         },
+        "selection_quote_replies": {
+          "type": "boolean"
+        },
         "shell_snapshot": {
           "type": "boolean"
         },
diff --git a/codex-rs/features/src/lib.rs b/codex-rs/features/src/lib.rs
index 0aa019cb06..ef82362c90 100644
--- a/codex-rs/features/src/lib.rs
+++ b/codex-rs/features/src/lib.rs
@@ -176,6 +176,8 @@ pub enum Feature {
     VoiceTranscription,
     /// Enable experimental realtime voice conversation mode in the TUI.
     RealtimeConversation,
+    /// Enable selection-based quote replies in app-server clients.
+    SelectionQuoteReplies,
     /// Route interactive startup to the app-server-backed TUI implementation.
     TuiAppServer,
     /// Prevent idle system sleep while a turn is actively running.
@@ -819,6 +821,16 @@ pub const FEATURES: &[FeatureSpec] = &[
         stage: Stage::UnderDevelopment,
         default_enabled: false,
     },
+    FeatureSpec {
+        id: Feature::SelectionQuoteReplies,
+        key: "selection_quote_replies",
+        stage: Stage::Experimental {
+            name: "Selection quote replies",
+            menu_description: "Show a quote-reply action when you select text in a conversation and insert the selection into the composer as a quoted reply.",
+            announcement: "",
+        },
+        default_enabled: false,
+    },
     FeatureSpec {
         id: Feature::TuiAppServer,
         key: "tui_app_server",
diff --git a/codex-rs/features/src/tests.rs b/codex-rs/features/src/tests.rs
index 4943a1ccf8..44c69cf892 100644
--- a/codex-rs/features/src/tests.rs
+++ b/codex-rs/features/src/tests.rs
@@ -150,6 +150,26 @@ fn tool_call_mcp_elicitation_is_stable_and_disabled_by_default() {
     assert_eq!(Feature::ToolCallMcpElicitation.default_enabled(), false);
 }
 
+#[test]
+fn selection_quote_replies_is_experimental_and_user_toggleable() {
+    let spec = Feature::SelectionQuoteReplies.info();
+    let stage = spec.stage;
+
+    assert!(matches!(stage, Stage::Experimental { .. }));
+    assert_eq!(
+        stage.experimental_menu_name(),
+        Some("Selection quote replies")
+    );
+    assert_eq!(
+        stage.experimental_menu_description(),
+        Some(
+            "Show a quote-reply action when you select text in a conversation and insert the selection into the composer as a quoted reply."
+        )
+    );
+    assert_eq!(stage.experimental_announcement(), None);
+    assert_eq!(Feature::SelectionQuoteReplies.default_enabled(), false);
+}
+
 #[test]
 fn image_detail_original_feature_is_under_development() {
     assert_eq!(