diff --git a/codex-rs/tui/src/chatwidget/tests.rs b/codex-rs/tui/src/chatwidget/tests.rs
index 3b61203399..29742c484a 100644
--- a/codex-rs/tui/src/chatwidget/tests.rs
+++ b/codex-rs/tui/src/chatwidget/tests.rs
@@ -441,6 +441,179 @@ fn open_fixture(name: &str) -> File {
     File::open(name).expect("open fixture file")
 }
 
+#[test]
+fn streaming_then_final_message_does_not_duplicate_bullet_line() {
+    // This reproduces a user report where a specific bullet line was shown twice.
+    // We simulate streaming deltas for a markdown list, then send the final
+    // assistant message. The expected behavior is that each logical line appears once.
+
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual();
+
+    // The full assistant message (single final message in the fixture)
+    let full = concat!(
+        "1. **Summary**\n",
+        "   - Updated the chat composer footer to highlight the remaining context percentage in yellow whenever the available context drops below 20%.\n",
+        "   - Left the indicator dimmed when the remaining context is at normal levels to maintain the existing appearance in non-critical situations.\n\n",
+        "2. **Testing**\n",
+        "   - `cargo test -p codex-tui`\n\n",
+        "3. **Next steps**\n",
+        "   - Let me know if you would like me to run `just fix -p codex-tui` to apply the project-specific lint fixes.\n\n",
+        "**Quick recap:** The context-left indicator now stands out in yellow when less than 20% of the context window remains, helping users notice the low-context condition.\n",
+    );
+
+    // Stream the content in realistic chunks; notably split the second bullet
+    // so that it crosses delta boundaries (mirrors typical network trickle).
+    let deltas = [
+        "1. **Summary**\n",
+        "   - Updated the chat composer footer to highlight the remaining context percentage in yellow whenever the available context drops below 20%.\n",
+        "   - Left the indicator ",
+        "dimmed when the remaining context is at normal levels to maintain the existing appearance in non-critical situations.\n\n",
+        "2. **Testing**\n",
+        "   - `cargo test -p codex-tui`\n\n",
+        "3. **Next steps**\n",
+        "   - Let me know if you would like me to run `just fix -p codex-tui` to apply the project-specific lint fixes.\n\n",
+        "**Quick recap:** The context-left indicator now stands out in yellow when less than 20% of the context window remains, helping users notice the low-context condition.\n",
+    ];
+
+    // Drive streaming with commit ticks.
+    let mut transcript = String::new();
+    for d in deltas {
+        chat.handle_codex_event(Event {
+            id: "s".into(),
+            msg: EventMsg::AgentMessageDelta(AgentMessageDeltaEvent { delta: d.into() }),
+        });
+        // Allow at most one line to be committed per tick.
+        chat.on_commit_tick();
+        // Drain and accumulate history lines during streaming.
+        for lines in drain_insert_history(&mut rx) {
+            transcript.push_str(&lines_to_single_string(&lines));
+        }
+    }
+
+    // Send the final message, which should flush any tail without duplication.
+    chat.handle_codex_event(Event {
+        id: "s".into(),
+        msg: EventMsg::AgentMessage(AgentMessageEvent {
+            message: full.to_string(),
+        }),
+    });
+
+    // Collect the entire transcript emitted into history.
+    let cells = drain_insert_history(&mut rx);
+    for lines in cells {
+        transcript.push_str(&lines_to_single_string(&lines));
+    }
+
+    // Count occurrences of the specific bullet (case-sensitive prefix makes the check robust).
+    let needle = "Left the indicator dimmed";
+    let count = transcript.matches(needle).count();
+    // Assert once; this is red if current behavior duplicates the line.
+    assert_eq!(
+        count, 1,
+        "expected bullet line to appear once (got {count}) in:\n{transcript}"
+    );
+}
+
+#[test]
+fn streaming_preserves_legit_duplicate_lines() {
+    // Two identical bullet lines are legitimate and must both appear.
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual();
+
+    let deltas = ["- duplicate\n", "- duplicate\n"];
+
+    for d in deltas {
+        chat.handle_codex_event(Event {
+            id: "dup".into(),
+            msg: EventMsg::AgentMessageDelta(AgentMessageDeltaEvent { delta: d.into() }),
+        });
+        chat.on_commit_tick();
+        // drain incremental
+        let _ = drain_insert_history(&mut rx);
+    }
+
+    // Finalize with empty final message (no new content) to close the stream.
+    chat.handle_codex_event(Event {
+        id: "dup".into(),
+        msg: EventMsg::AgentMessage(AgentMessageEvent {
+            message: "".to_string(),
+        }),
+    });
+
+    let cells = drain_insert_history(&mut rx);
+    let mut transcript = String::new();
+    for lines in cells {
+        transcript.push_str(&lines_to_single_string(&lines));
+    }
+
+    let needle = "- duplicate";
+    let count = transcript.matches(needle).count();
+    assert_eq!(
+        count, 2,
+        "expected both duplicate lines to be present: {transcript}"
+    );
+}
+
+#[test]
+fn double_line_repro_fixture_renders_line_once() {
+    use codex_core::protocol::AgentMessageEvent;
+    use codex_core::protocol::Event;
+    use codex_core::protocol::EventMsg;
+    use pretty_assertions::assert_eq;
+
+    // Build a chat widget and channels without spawning the agent.
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual();
+
+    // Load the user-provided network log JSON and extract the final assistant text.
+    let file = open_fixture("double-line-repro.json");
+    let v: serde_json::Value = serde_json::from_reader(file).expect("parse JSON");
+    let outputs = v
+        .get("response")
+        .and_then(|r| r.get("output"))
+        .and_then(|o| o.as_array())
+        .expect("response.output array present");
+    let mut assistant_text = String::new();
+    for item in outputs {
+        if item.get("type").and_then(|t| t.as_str()) == Some("message") {
+            if let Some(content) = item.get("content").and_then(|c| c.as_array()) {
+                for c in content {
+                    if c.get("type").and_then(|t| t.as_str()) == Some("output_text") {
+                        if let Some(text) = c.get("text").and_then(|t| t.as_str()) {
+                            assistant_text.push_str(text);
+                        }
+                    }
+                }
+            }
+        }
+    }
+    assert!(
+        !assistant_text.is_empty(),
+        "expected assistant text extracted from fixture"
+    );
+
+    // Inject as a final assistant message (no streaming deltas) to mirror the log.
+    chat.handle_codex_event(Event {
+        id: "sub-repro".into(),
+        msg: EventMsg::AgentMessage(AgentMessageEvent {
+            message: assistant_text.clone(),
+        }),
+    });
+
+    // Drain history insertions and build a single plain-text blob for searching.
+    let cells = drain_insert_history(&mut rx);
+    let mut blob = String::new();
+    for lines in cells {
+        blob.push_str(&lines_to_single_string(&lines));
+    }
+
+    // The specific line reported as duplicated should appear exactly once.
+    let needle = "Left the indicator dimmed";
+    let count = blob.matches(needle).count();
+    assert_eq!(
+        count, 1,
+        "expected line to appear once, found {count} in output:\n{blob}"
+    );
+}
+
 #[test]
 fn empty_enter_during_task_does_not_queue() {
     let (mut chat, _rx, _op_rx) = make_chatwidget_manual();
diff --git a/codex-rs/tui/src/markdown_stream.rs b/codex-rs/tui/src/markdown_stream.rs
index 5dc84cb11d..55370b9cec 100644
--- a/codex-rs/tui/src/markdown_stream.rs
+++ b/codex-rs/tui/src/markdown_stream.rs
@@ -65,21 +65,6 @@ impl MarkdownStreamCollector {
         {
             complete_line_count -= 1;
         }
-        // Heuristic: if the buffer ends with a double newline and the last non-blank
-        // rendered line looks like a list bullet with inline content (e.g., "- item"),
-        // defer committing that line. Subsequent context (e.g., another list item)
-        // can cause the renderer to split the bullet marker and text into separate
-        // logical lines ("- " then "item"), which would otherwise duplicate content.
-        if self.buffer.ends_with("\n\n") && complete_line_count > 0 {
-            let last = &rendered[complete_line_count - 1];
-            let mut text = String::new();
-            for s in &last.spans {
-                text.push_str(&s.content);
-            }
-            if text.starts_with("- ") && text.trim() != "-" {
-                complete_line_count = complete_line_count.saturating_sub(1);
-            }
-        }
         if !self.buffer.ends_with('\n') {
             complete_line_count = complete_line_count.saturating_sub(1);
             // If we're inside an unclosed fenced code block, also drop the
@@ -143,6 +128,9 @@ impl MarkdownStreamCollector {
                 s.push_str(&sp.content);
             }
             if is_short_plain_word(&s) {
+                // Advance commit pointer for the safe portion, but withhold the
+                // single ambiguous short token to avoid duplication on finalize.
+                self.committed_line_count = complete_line_count.saturating_sub(1);
                 return Vec::new();
             }
         }
diff --git a/codex-rs/tui/src/streaming/controller.rs b/codex-rs/tui/src/streaming/controller.rs
index 4edea186dd..b448ae9547 100644
--- a/codex-rs/tui/src/streaming/controller.rs
+++ b/codex-rs/tui/src/streaming/controller.rs
@@ -115,11 +115,64 @@ impl StreamController {
             let mut out_lines: Lines = Vec::new();
             {
                 let state = &mut self.state;
-                if !remaining.is_empty() {
-                    state.enqueue(remaining);
+                // Drain queued lines.
+                let mut step = state.drain_all();
+                if let Some(first) = step.history.first() {
+                    let mut s = String::new();
+                    for sp in &first.spans {
+                        s.push_str(&sp.content);
+                    }
+                    let key = s.trim_end().to_string();
+                    if state.last_emitted_line_text.as_deref() == Some(&key) {
+                        step.history.remove(0);
+                    }
                 }
-                let step = state.drain_all();
                 out_lines.extend(step.history);
+
+                // At the seam between drained and remaining, avoid a single duplicate.
+                let mut remaining = remaining;
+                if let (Some(last_out), Some(first_rem)) = (out_lines.last(), remaining.first()) {
+                    let mut a = String::new();
+                    for sp in &last_out.spans {
+                        a.push_str(&sp.content);
+                    }
+                    let mut b = String::new();
+                    for sp in &first_rem.spans {
+                        b.push_str(&sp.content);
+                    }
+                    if a.trim_end() == b.trim_end() {
+                        remaining.remove(0);
+                    }
+                } else if out_lines.is_empty() {
+                    // No drained lines; compare remaining against last emitted.
+                    if let Some(first_rem) = remaining.first() {
+                        let mut b = String::new();
+                        for sp in &first_rem.spans {
+                            b.push_str(&sp.content);
+                        }
+                        if state
+                            .last_emitted_line_text
+                            .as_deref()
+                            .map(|t| t == b.trim_end())
+                            .unwrap_or(false)
+                        {
+                            remaining.remove(0);
+                        }
+                    }
+                }
+                out_lines.extend(remaining);
+
+                // Update last emitted tracker for the stream.
+                if let Some(last) = out_lines.last() {
+                    let mut s = String::new();
+                    for sp in &last.spans {
+                        s.push_str(&sp.content);
+                    }
+                    let key = s.trim_end().to_string();
+                    if !key.is_empty() {
+                        state.last_emitted_line_text = Some(key);
+                    }
+                }
             }
             if !out_lines.is_empty() {
                 // Insert as a HistoryCell so display drops the header while transcript keeps it.
@@ -129,6 +182,10 @@ impl StreamController {
                 )));
             }
 
+            // Ensure commit animation (status ticker) is stopped when we flush immediately
+            // at the end of a stream so the timer does not bleed into the UI.
+            sink.stop_commit_animation();
+
             // Cleanup
             self.state.clear();
             // Allow a subsequent block in this turn to emit its header.
@@ -156,12 +213,37 @@ impl StreamController {
         if !self.active {
             return false;
         }
-        let step = { self.state.step() };
+        let mut step = { self.state.step() };
         if !step.history.is_empty() {
-            sink.insert_history_cell(Box::new(history_cell::AgentMessageCell::new(
-                step.history,
-                self.header.maybe_emit_header(),
-            )));
+            // Drop a single duplicate at the seam with the previous tick.
+            if let Some(first) = step.history.first() {
+                let mut s = String::new();
+                for sp in &first.spans {
+                    s.push_str(&sp.content);
+                }
+                let key = s.trim_end().to_string();
+                if self.state.last_emitted_line_text.as_deref() == Some(&key) {
+                    step.history.remove(0);
+                }
+            }
+            // Set to last non-empty line's text if present.
+            for l in step.history.iter().rev() {
+                let mut s = String::new();
+                for sp in &l.spans {
+                    s.push_str(&sp.content);
+                }
+                let key = s.trim_end().to_string();
+                if !key.is_empty() {
+                    self.state.last_emitted_line_text = Some(key);
+                    break;
+                }
+            }
+            if !step.history.is_empty() {
+                sink.insert_history_cell(Box::new(history_cell::AgentMessageCell::new(
+                    step.history,
+                    self.header.maybe_emit_header(),
+                )));
+            }
         }
 
         let is_idle = self.state.is_idle();
diff --git a/codex-rs/tui/src/streaming/mod.rs b/codex-rs/tui/src/streaming/mod.rs
index 3fc81360ba..236b6becd4 100644
--- a/codex-rs/tui/src/streaming/mod.rs
+++ b/codex-rs/tui/src/streaming/mod.rs
@@ -6,6 +6,7 @@ pub(crate) struct StreamState {
     pub(crate) collector: MarkdownStreamCollector,
     pub(crate) streamer: AnimatedLineStreamer,
     pub(crate) has_seen_delta: bool,
+    pub(crate) last_emitted_line_text: Option<String>,
 }
 
 impl StreamState {
@@ -14,12 +15,14 @@ impl StreamState {
             collector: MarkdownStreamCollector::new(),
             streamer: AnimatedLineStreamer::new(),
             has_seen_delta: false,
+            last_emitted_line_text: None,
         }
     }
     pub(crate) fn clear(&mut self) {
         self.collector.clear();
         self.streamer.clear();
         self.has_seen_delta = false;
+        self.last_emitted_line_text = None;
     }
     pub(crate) fn step(&mut self) -> crate::markdown_stream::StepResult {
         self.streamer.step()