diff --git a/app/androidApp/src/main/kotlin/com/example/aiapp/TranscriptItems.kt b/app/androidApp/src/main/kotlin/com/example/aiapp/TranscriptItems.kt
index 47b196c..6c6ee2c 100644
--- a/app/androidApp/src/main/kotlin/com/example/aiapp/TranscriptItems.kt
+++ b/app/androidApp/src/main/kotlin/com/example/aiapp/TranscriptItems.kt
@@ -433,16 +433,24 @@ fun foldEvent(items: List<TranscriptItem>, entry: SeqEvent): List<TranscriptItem
             }
         }
         is SessionEvent.ToolStart ->
-            items +
-                TranscriptItem.ToolRun(
-                    entry.seq,
-                    event.id,
-                    runIdFor(items, event.id, event.tool),
-                    event.tool,
-                    event.input,
-                    "",
-                    done = false,
-                )
+            // A call id names one call for its whole lifetime. Codex can repeat the start while
+            // recovering an in-flight item; appending that replay made two rows with one key, and
+            // Compose aborts the entire LazyColumn when it encounters them. Ignoring the replay
+            // also repairs transcripts which already contain it when they are folded on reopen.
+            if (items.any { it is TranscriptItem.ToolRun && it.id == event.id }) {
+                items
+            } else {
+                items +
+                    TranscriptItem.ToolRun(
+                        entry.seq,
+                        event.id,
+                        runIdFor(items, event.id, event.tool),
+                        event.tool,
+                        event.input,
+                        "",
+                        done = false,
+                    )
+            }
         is SessionEvent.ToolUpdate -> updateTool(items, event.id) { it.copy(output = event.output) }
         is SessionEvent.ToolEnd ->
             // Created when its start is not here, rather than dropped. A fold that only ever
diff --git a/app/androidApp/src/test/kotlin/com/example/aiapp/TranscriptItemsTest.kt b/app/androidApp/src/test/kotlin/com/example/aiapp/TranscriptItemsTest.kt
index 185fa7f..be7b2ea 100644
--- a/app/androidApp/src/test/kotlin/com/example/aiapp/TranscriptItemsTest.kt
+++ b/app/androidApp/src/test/kotlin/com/example/aiapp/TranscriptItemsTest.kt
@@ -142,6 +142,23 @@ class TranscriptItemsTest {
         assertTrue(items.none { it is TranscriptItem.TurnBreak }, "$items")
     }
 
+    @Test
+    fun a_repeated_tool_start_is_still_one_row() {
+        val start = SessionEvent.ToolStart("exec-1", "Bash", "{\"command\":\"cargo test\"}")
+        val items =
+            fold(
+                start,
+                SessionEvent.AssistantText("The test run is still going."),
+                start,
+                SessionEvent.ToolEnd("exec-1", "finished"),
+            )
+
+        val tools = items.filterIsInstance<TranscriptItem.ToolRun>()
+        assertEquals(1, tools.size, "$items")
+        assertEquals("finished", tools.single().output)
+        assertTrue(tools.single().done)
+    }
+
     /**
      * The page-join half of the same rule. A boundary that cuts one reply leaves an unfinished half
      * to be rejoined; a boundary that lands between two turns must not join anything, or paging