diff --git a/apps/website/content/docs/langgraph/guides/time-travel.mdx b/apps/website/content/docs/langgraph/guides/time-travel.mdx
index c73b7ccf4..7012e1ba7 100644
--- a/apps/website/content/docs/langgraph/guides/time-travel.mdx
+++ b/apps/website/content/docs/langgraph/guides/time-travel.mdx
@@ -36,7 +36,7 @@ The example resolves its connection details at runtime from the host that serves
 
 ### Reading the checkpoint history
 
-The component injects the agent and derives the timeline from it. `langGraphHistory()` is LangGraph's own view of the thread: an array of `ThreadState` snapshots. `selectedIndex` is local interface state, holding the row the user clicked last.
+The component injects the agent and derives the timeline from it. `langGraphHistory()` is LangGraph's own view of the thread: an array of `ThreadState` snapshots. `selectedCheckpointId` is local interface state, holding the checkpoint the user clicked last. New checkpoints can move existing rows, so selection follows the identifier across history refreshes.
 
 <ExampleCode file="time-travel.component.ts" region="history" title="time-travel.component.ts — the history signals" />
 
diff --git a/cockpit/langgraph/time-travel/angular/e2e/time-travel.spec.ts b/cockpit/langgraph/time-travel/angular/e2e/time-travel.spec.ts
index d37ef4b04..09bf1da67 100644
--- a/cockpit/langgraph/time-travel/angular/e2e/time-travel.spec.ts
+++ b/cockpit/langgraph/time-travel/angular/e2e/time-travel.spec.ts
@@ -83,4 +83,5 @@ test('time-travel: fork starts at the selected checkpoint, not the thread tip',
       'Try a different approach from here.',
       'This reply belongs to the checkpoint fork.',
     ]);
+  await expect(page.locator('.row--active .id')).toHaveText(checkpointId);
 });
diff --git a/cockpit/langgraph/time-travel/angular/src/app/time-travel.component.ts b/cockpit/langgraph/time-travel/angular/src/app/time-travel.component.ts
index 7bc007547..c5bf6877b 100644
--- a/cockpit/langgraph/time-travel/angular/src/app/time-travel.component.ts
+++ b/cockpit/langgraph/time-travel/angular/src/app/time-travel.component.ts
@@ -155,10 +155,16 @@ import { ExampleChatLayoutComponent } from '@threadplane/example-layouts';
             <p class="empty">No checkpoints yet. Send a message to begin.</p>
           }
 
-          @for (state of checkpoints(); track $index; let i = $index) {
-            <div class="row" [class.row--active]="i === selectedIndex()">
+          @for (state of checkpoints(); track state.checkpoint?.checkpoint_id ?? $index; let i = $index) {
+            <div
+              class="row"
+              [class.row--active]="state.checkpoint?.checkpoint_id === selectedCheckpointId()"
+            >
               <!-- Numbered badge -->
-              <span class="badge" [class.badge--active]="i === selectedIndex()">
+              <span
+                class="badge"
+                [class.badge--active]="state.checkpoint?.checkpoint_id === selectedCheckpointId()"
+              >
                 {{ i + 1 }}
               </span>
 
@@ -175,14 +181,14 @@ import { ExampleChatLayoutComponent } from '@threadplane/example-layouts';
                 <button
                   class="btn"
                   title="Select this checkpoint as the active branch"
-                  (click)="select(state, i)"
+                  (click)="select(state)"
                 >
                   Select
                 </button>
                 <button
                   class="btn"
                   title="Fork from this checkpoint"
-                  (click)="fork(state, i)"
+                  (click)="fork(state)"
                 >
                   Fork
                 </button>
@@ -199,8 +205,8 @@ export class TimeTravelComponent {
   // #region history
   protected readonly agent = injectAgent();
 
-  /** Index of the currently selected checkpoint in the sidebar. */
-  protected readonly selectedIndex = signal<number>(-1);
+  /** Selection survives new checkpoints being prepended to the history. */
+  protected readonly selectedCheckpointId = signal<string | null>(null);
 
   /** Checkpoint history derived from the agent. */
   protected readonly checkpoints = computed(
@@ -226,9 +232,9 @@ export class TimeTravelComponent {
    * `setBranch()` records the identifier in the agent's `branch()` signal.
    * It starts no run: it is a pointer the interface can read back.
    */
-  protected select(state: ThreadState<any>, index: number): void {
+  protected select(state: ThreadState<any>): void {
     if (state.checkpoint?.checkpoint_id) {
-      this.selectedIndex.set(index);
+      this.selectedCheckpointId.set(state.checkpoint.checkpoint_id);
       this.agent.setBranch(state.checkpoint.checkpoint_id);
     }
   }
@@ -240,10 +246,10 @@ export class TimeTravelComponent {
    * rather than at its tip, so the new run hangs off the chosen checkpoint
    * and the original path stays intact.
    */
-  protected fork(state: ThreadState<any>, index: number): void {
+  protected fork(state: ThreadState<any>): void {
     const checkpointId = state.checkpoint?.checkpoint_id;
     if (!checkpointId) return;
-    this.selectedIndex.set(index);
+    this.selectedCheckpointId.set(checkpointId);
     void this.agent.submit(
       { message: 'Try a different approach from here.' },
       { checkpointId },
diff --git a/scripts/react-parity/baseline.json b/scripts/react-parity/baseline.json
index 203dda8ee..bebab6c3b 100644
--- a/scripts/react-parity/baseline.json
+++ b/scripts/react-parity/baseline.json
@@ -1,6 +1,6 @@
 {
   "schemaVersion": 1,
-  "baselineHead": "2082b01664a220ab30473d5a991a79154fba7a25",
+  "baselineHead": "82c5469743a8fc3484d395f03372dc6c6975e9b2",
   "sourceState": {
     "modified": [],
     "untracked": []
@@ -2536,7 +2536,7 @@
       "id": "doc:apps/website/content/docs/langgraph/guides/time-travel.mdx",
       "kind": "doc",
       "path": "apps/website/content/docs/langgraph/guides/time-travel.mdx",
-      "sha256": "34ea8b1fbb52db5ba0a49e679104c8ca78c4ef476edcd058b201cac301d88022"
+      "sha256": "ddd916b992331e56abe4bf72b0f074dd7649bd521e1702c12a078bb1a6c228ba"
     },
     {
       "id": "doc:apps/website/content/docs/middleware/api/client-tool-helpers.mdx",