Parse and expose stream errors (#2540)

codex-rs/tui/src/chatwidget.rs

@@ -23,6 +23,7 @@ use codex_core::protocol::McpToolCallBeginEvent;
 use codex_core::protocol::McpToolCallEndEvent;
 use codex_core::protocol::Op;
 use codex_core::protocol::PatchApplyBeginEvent;
+use codex_core::protocol::StreamErrorEvent;
 use codex_core::protocol::TaskCompleteEvent;
 use codex_core::protocol::TokenUsage;
 use codex_core::protocol::TurnDiffEvent;
@@ -327,6 +328,12 @@ impl ChatWidget {
     fn on_background_event(&mut self, message: String) {
         debug!("BackgroundEvent: {message}");
     }
+
+    fn on_stream_error(&mut self, message: String) {
+        // Show stream errors in the transcript so users see retry/backoff info.
+        self.add_to_history(history_cell::new_stream_error_event(message));
+        self.mark_needs_redraw();
+    }
     /// Periodic tick to commit at most one queued line to history with a small delay,
     /// animating the output.
     pub(crate) fn on_commit_tick(&mut self) {
@@ -690,6 +697,7 @@ impl ChatWidget {
             EventMsg::BackgroundEvent(BackgroundEventEvent { message }) => {
                 self.on_background_event(message)
             }
+            EventMsg::StreamError(StreamErrorEvent { message }) => self.on_stream_error(message),
         }
         // Coalesce redraws: issue at most one after handling the event
         if self.needs_redraw {

codex-rs/tui/src/chatwidget/tests.rs

@@ -19,6 +19,7 @@ use codex_core::protocol::ExecCommandEndEvent;
 use codex_core::protocol::FileChange;
 use codex_core::protocol::PatchApplyBeginEvent;
 use codex_core::protocol::PatchApplyEndEvent;
+use codex_core::protocol::StreamErrorEvent;
 use codex_core::protocol::TaskCompleteEvent;
 use crossterm::event::KeyCode;
 use crossterm::event::KeyEvent;
@@ -823,6 +824,25 @@ fn plan_update_renders_history_cell() {
     assert!(blob.contains("Write tests"));
 }
 
+#[test]
+fn stream_error_is_rendered_to_history() {
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual();
+    let msg = "stream error: stream disconnected before completion: idle timeout waiting for SSE; retrying 1/5 in 211ms…";
+    chat.handle_codex_event(Event {
+        id: "sub-1".into(),
+        msg: EventMsg::StreamError(StreamErrorEvent {
+            message: msg.to_string(),
+        }),
+    });
+
+    let cells = drain_insert_history(&mut rx);
+    assert!(!cells.is_empty(), "expected a history cell for StreamError");
+    let blob = lines_to_single_string(cells.last().unwrap());
+    assert!(blob.contains("⚠ "));
+    assert!(blob.contains("stream error:"));
+    assert!(blob.contains("idle timeout waiting for SSE"));
+}
+
 #[test]
 fn headers_emitted_on_stream_begin_for_answer_and_not_for_reasoning() {
     let (mut chat, mut rx, _op_rx) = make_chatwidget_manual();

codex-rs/tui/src/history_cell.rs

@@ -751,6 +751,12 @@ pub(crate) fn new_error_event(message: String) -> PlainHistoryCell {
     PlainHistoryCell { lines }
 }
 
+pub(crate) fn new_stream_error_event(message: String) -> PlainHistoryCell {
+    let lines: Vec<Line<'static>> =
+        vec![vec!["⚠ ".magenta().bold(), message.dim()].into(), "".into()];
+    PlainHistoryCell { lines }
+}
+
 /// Render a user‑friendly plan update styled like a checkbox todo list.
 pub(crate) fn new_plan_update(update: UpdatePlanArgs) -> PlainHistoryCell {
     let UpdatePlanArgs { explanation, plan } = update;