diff --git a/codex-rs/Cargo.lock b/codex-rs/Cargo.lock
index 2e5b8337c1..1465406861 100644
--- a/codex-rs/Cargo.lock
+++ b/codex-rs/Cargo.lock
@@ -2104,7 +2104,6 @@ name = "codex-backend-client"
 version = "0.0.0"
 dependencies = [
  "anyhow",
- "chrono",
  "codex-api",
  "codex-backend-openapi-models",
  "codex-client",
diff --git a/codex-rs/backend-client/Cargo.toml b/codex-rs/backend-client/Cargo.toml
index 9e7a55f66c..d2e374ae2a 100644
--- a/codex-rs/backend-client/Cargo.toml
+++ b/codex-rs/backend-client/Cargo.toml
@@ -13,7 +13,6 @@ workspace = true
 
 [dependencies]
 anyhow = "1"
-chrono = { workspace = true, features = ["serde"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls"] }
diff --git a/codex-rs/backend-client/src/types.rs b/codex-rs/backend-client/src/types.rs
index dc7a6aad19..7b25c24c43 100644
--- a/codex-rs/backend-client/src/types.rs
+++ b/codex-rs/backend-client/src/types.rs
@@ -8,8 +8,6 @@ pub use codex_backend_openapi_models::models::RateLimitStatusPayload;
 pub use codex_backend_openapi_models::models::RateLimitWindowSnapshot;
 pub use codex_backend_openapi_models::models::TaskListItem;
 
-use chrono::DateTime;
-use chrono::Utc;
 use serde::Deserialize;
 use serde::de::Deserializer;
 use serde_json::Value;
@@ -26,8 +24,7 @@ pub struct CodexWorkspaceMessage {
     pub message_id: String,
     pub message_type: CodexWorkspaceMessageType,
     pub message_body: String,
-    pub created_at: DateTime<Utc>,
-    pub updated_at: DateTime<Utc>,
+    pub created_at: String,
 }
 
 #[derive(Clone, Copy, Debug, Deserialize, PartialEq, Eq)]
diff --git a/codex-rs/features/src/lib.rs b/codex-rs/features/src/lib.rs
index acb6fa195e..f86acd0451 100644
--- a/codex-rs/features/src/lib.rs
+++ b/codex-rs/features/src/lib.rs
@@ -223,6 +223,8 @@ pub enum Feature {
     PreventIdleSleep,
     /// Enable workspace-specific owner nudge copy and prompts in the TUI.
     WorkspaceOwnerUsageNudge,
+    /// Enable workspace headline and announcement message polling.
+    WorkspaceMessages,
     /// Legacy rollout flag for Responses API WebSocket transport experiments.
     ResponsesWebsockets,
     /// Legacy rollout flag for Responses API WebSocket transport v2 experiments.
@@ -1111,6 +1113,12 @@ pub const FEATURES: &[FeatureSpec] = &[
         stage: Stage::UnderDevelopment,
         default_enabled: false,
     },
+    FeatureSpec {
+        id: Feature::WorkspaceMessages,
+        key: "workspace_messages",
+        stage: Stage::UnderDevelopment,
+        default_enabled: false,
+    },
     FeatureSpec {
         id: Feature::ResponsesWebsockets,
         key: "responses_websockets",
diff --git a/codex-rs/tui/src/lib.rs b/codex-rs/tui/src/lib.rs
index f99e32552d..d8648eb51f 100644
--- a/codex-rs/tui/src/lib.rs
+++ b/codex-rs/tui/src/lib.rs
@@ -42,6 +42,7 @@ use codex_config::format_config_error_with_source;
 use codex_exec_server::EnvironmentManager;
 use codex_exec_server::EnvironmentManagerArgs;
 use codex_exec_server::ExecServerRuntimePaths;
+use codex_features::Feature;
 use codex_login::AuthConfig;
 use codex_login::default_client::set_default_client_residency_requirement;
 use codex_login::enforce_login_restrictions;
@@ -1105,7 +1106,9 @@ async fn run_ratatui_app(
     color_eyre::install()?;
 
     tooltips::announcement::prewarm();
-    workspace_messages::prewarm_headline(&initial_config);
+    if initial_config.features.enabled(Feature::WorkspaceMessages) {
+        workspace_messages::prewarm_headline(&initial_config);
+    }
 
     // Forward panic reports through tracing so they appear in the UI status
     // line, but do not swallow the default/color-eyre panic handler.