diff --git a/codex-rs/app-server/src/request_processors/thread_processor.rs b/codex-rs/app-server/src/request_processors/thread_processor.rs
index b78c53a383..9c0b7072fe 100644
--- a/codex-rs/app-server/src/request_processors/thread_processor.rs
+++ b/codex-rs/app-server/src/request_processors/thread_processor.rs
@@ -2448,6 +2448,8 @@ impl ThreadRequestProcessor {
                     SortDirection::Asc => StoreSortDirection::Asc,
                     SortDirection::Desc => StoreSortDirection::Desc,
                 },
+                after_updated_at: None,
+                through_updated_at: None,
             })
             .await
             .map_err(|err| match err {
diff --git a/codex-rs/thread-store/src/error.rs b/codex-rs/thread-store/src/error.rs
index bc5e8ed7c4..3ce4019bc4 100644
--- a/codex-rs/thread-store/src/error.rs
+++ b/codex-rs/thread-store/src/error.rs
@@ -46,6 +46,13 @@ pub enum ThreadStoreError {
         operation: &'static str,
     },
 
+    /// The store cannot return the requested result within a required resource limit.
+    #[error("thread-store resource exhausted: {message}")]
+    ResourceExhausted {
+        /// User-facing explanation of the exhausted resource.
+        message: String,
+    },
+
     /// Catch-all for implementation failures that do not fit a more specific category.
     #[error("thread-store internal error: {message}")]
     Internal {
diff --git a/codex-rs/thread-store/src/in_memory.rs b/codex-rs/thread-store/src/in_memory.rs
index cb3f198ff3..0c9b2c60f5 100644
--- a/codex-rs/thread-store/src/in_memory.rs
+++ b/codex-rs/thread-store/src/in_memory.rs
@@ -90,6 +90,8 @@ mod tests {
                 cursor: None,
                 page_size: 10,
                 sort_direction: SortDirection::Asc,
+                after_updated_at: None,
+                through_updated_at: None,
             })
             .await
             .expect_err("default list_items should be unsupported");
diff --git a/codex-rs/thread-store/src/store.rs b/codex-rs/thread-store/src/store.rs
index 67ee603f49..8ae27ba8c6 100644
--- a/codex-rs/thread-store/src/store.rs
+++ b/codex-rs/thread-store/src/store.rs
@@ -111,7 +111,9 @@ pub trait ThreadStore: Any + Send + Sync {
         })
     }
 
-    /// Lists persisted items within a stored thread, optionally filtered to a turn.
+    /// Lists persisted items within a stored thread, optionally filtered to a turn or update
+    /// interval. Implementations must return [`ThreadStoreError::Unsupported`] rather than ignore
+    /// timestamp bounds they cannot apply.
     fn list_items(&self, _params: ListItemsParams) -> ThreadStoreFuture<'_, ItemPage> {
         Box::pin(async {
             Err(ThreadStoreError::Unsupported {
diff --git a/codex-rs/thread-store/src/types.rs b/codex-rs/thread-store/src/types.rs
index 4e688eca6f..a2dbac6dab 100644
--- a/codex-rs/thread-store/src/types.rs
+++ b/codex-rs/thread-store/src/types.rs
@@ -387,6 +387,13 @@ pub struct ListItemsParams {
     pub page_size: usize,
     /// Sort direction requested by the caller.
     pub sort_direction: SortDirection,
+    /// Exclusive lower bound for item updates. Requires `through_updated_at` when set.
+    #[serde(default)]
+    pub after_updated_at: Option<DateTime<Utc>>,
+    /// Inclusive upper bound for item updates. Implementations that do not support bounded reads
+    /// must return [`crate::ThreadStoreError::Unsupported`] instead of ignoring this field.
+    #[serde(default)]
+    pub through_updated_at: Option<DateTime<Utc>>,
 }
 
 /// A projected app-server `ThreadItem` snapshot within a turn.
@@ -408,6 +415,9 @@ pub struct ItemPage {
     pub next_cursor: Option<String>,
     /// Opaque cursor for fetching in the opposite direction.
     pub backwards_cursor: Option<String>,
+    /// Inclusive update bound applied by the store, echoed for bounded reads.
+    #[serde(default)]
+    pub read_through_updated_at: Option<DateTime<Utc>>,
 }
 
 /// Store-owned thread metadata used by list/read/resume responses.