diff --git a/src/services/worker-types.ts b/src/services/worker-types.ts
index 1a8557a0..79dc9199 100644
--- a/src/services/worker-types.ts
+++ b/src/services/worker-types.ts
@@ -124,6 +124,7 @@ export interface Observation {
   id: number;
   memory_session_id: string;  // Renamed from sdk_session_id
   project: string;
+  merged_into_project: string | null;
   platform_source: string;
   type: string;
   title: string;
diff --git a/src/services/worker/PaginationHelper.ts b/src/services/worker/PaginationHelper.ts
index 42ce1cce..07888ec7 100644
--- a/src/services/worker/PaginationHelper.ts
+++ b/src/services/worker/PaginationHelper.ts
@@ -80,6 +80,7 @@ export class PaginationHelper {
         o.id,
         o.memory_session_id,
         o.project,
+        o.merged_into_project,
         COALESCE(s.platform_source, 'claude') as platform_source,
         o.type,
         o.title,
@@ -100,8 +101,10 @@ export class PaginationHelper {
     const conditions: string[] = [];
 
     if (project) {
-      conditions.push('o.project = ?');
-      params.push(project);
+      // Include adopted merged-worktree rows so the parent project's view
+      // surfaces observations that originated under its merged children.
+      conditions.push('(o.project = ? OR o.merged_into_project = ?)');
+      params.push(project, project);
     }
     if (platformSource) {
       conditions.push(`COALESCE(s.platform_source, 'claude') = ?`);
@@ -156,8 +159,10 @@ export class PaginationHelper {
     const conditions: string[] = [];
 
     if (project) {
-      conditions.push('ss.project = ?');
-      params.push(project);
+      // Include adopted merged-worktree summaries so the parent project's view
+      // surfaces rows that originated under its merged children.
+      conditions.push('(ss.project = ? OR ss.merged_into_project = ?)');
+      params.push(project, project);
     }
 
     if (platformSource) {
diff --git a/src/ui/viewer-template.html b/src/ui/viewer-template.html
index c540310c..04f79156 100644
--- a/src/ui/viewer-template.html
+++ b/src/ui/viewer-template.html
@@ -1130,6 +1130,19 @@
       color: var(--color-text-muted);
     }
 
+    /* Merged-into-parent provenance badge */
+    .card-merged-badge {
+      padding: 1px 6px;
+      border-radius: 3px;
+      font-size: 9px;
+      font-weight: 500;
+      letter-spacing: 0.02em;
+      color: var(--color-text-muted);
+      background: var(--color-type-badge-bg);
+      border: 1px solid var(--color-border);
+      opacity: 0.85;
+    }
+
     .summary-card {
       border-color: var(--color-border-summary);
       background: var(--color-bg-summary);
diff --git a/src/ui/viewer/components/ObservationCard.tsx b/src/ui/viewer/components/ObservationCard.tsx
index 71352756..14fbe6cb 100644
--- a/src/ui/viewer/components/ObservationCard.tsx
+++ b/src/ui/viewer/components/ObservationCard.tsx
@@ -56,6 +56,11 @@ export function ObservationCard({ observation }: ObservationCardProps) {
             {observation.platform_source || 'claude'}
           </span>
           <span className="card-project">{observation.project}</span>
+          {observation.merged_into_project && (
+            <span className="card-merged-badge" title={`Merged into ${observation.merged_into_project}`}>
+              merged → {observation.merged_into_project}
+            </span>
+          )}
         </div>
         <div className="view-mode-toggles">
           {hasFactsContent && (
diff --git a/src/ui/viewer/types.ts b/src/ui/viewer/types.ts
index cf0403e1..4078e0e9 100644
--- a/src/ui/viewer/types.ts
+++ b/src/ui/viewer/types.ts
@@ -2,6 +2,7 @@ export interface Observation {
   id: number;
   memory_session_id: string;
   project: string;
+  merged_into_project?: string | null;
   platform_source: string;
   type: string;
   title: string | null;