diff --git a/src/expert-insurer/expert-insurer.service.ts b/src/expert-insurer/expert-insurer.service.ts
index 238617e..90f17d6 100644
--- a/src/expert-insurer/expert-insurer.service.ts
+++ b/src/expert-insurer/expert-insurer.service.ts
@@ -2148,6 +2148,20 @@ export class ExpertInsurerService {
     };
   }
 
+  /**
+   * Maps a raw history `actorType` string to either `"user"` or `"expert"`.
+   * - `"user"` → the action was taken by the car-owner / damaged party
+   * - `"expert"` → taken by any expert, system, or back-office actor
+   * - `null` → actorType was absent (unknown)
+   */
+  private static resolveTimelinePerformedBy(
+    actorType: string | undefined,
+  ): "user" | "expert" | null {
+    if (!actorType) return null;
+    if (actorType === "user") return "user";
+    return "expert";
+  }
+
   async getFileTimeline(
     insurerId: string,
     publicId: string,
@@ -2187,6 +2201,7 @@ export class ExpertInsurerService {
           faLabel: getEventFaLabel(ev),
           timestamp: ev.timestamp,
           actor: ev.actor ?? null,
+          performedBy: ExpertInsurerService.resolveTimelinePerformedBy(ev.actor?.actorType),
           metadata: ev.metadata ?? null,
         });
       }
@@ -2206,6 +2221,7 @@ export class ExpertInsurerService {
           faLabel: getEventFaLabel(ev),
           timestamp: ev.timestamp,
           actor: ev.actor ?? null,
+          performedBy: ExpertInsurerService.resolveTimelinePerformedBy(ev.actor?.actorType),
           metadata: ev.metadata ?? null,
         });
       }