diff --git a/apps/mana/apps/web/src/lib/data/sync.ts b/apps/mana/apps/web/src/lib/data/sync.ts
index 034aba4d1..01531e903 100644
--- a/apps/mana/apps/web/src/lib/data/sync.ts
+++ b/apps/mana/apps/web/src/lib/data/sync.ts
@@ -21,11 +21,20 @@ import {
 	fromSyncName,
 	beginApplyingTables,
 	FIELD_TIMESTAMPS_KEY,
+	FIELD_ACTORS_KEY,
+	LAST_ACTOR_KEY,
 	setPendingChangeListener,
 } from './database';
 import { isQuotaError, cleanupTombstones, notifyQuotaExceeded } from './quota';
 import { emitSyncTelemetry, categorizeSyncError } from './sync-telemetry';
-import type { Actor } from './events/actor';
+import { USER_ACTOR, type Actor } from './events/actor';
+
+/** Reads the per-field actor map off a record; empty for legacy rows. */
+function readFieldActors(record: unknown): Record<string, Actor> {
+	if (!record || typeof record !== 'object') return {};
+	const fa = (record as Record<string, unknown>)[FIELD_ACTORS_KEY];
+	return fa && typeof fa === 'object' ? (fa as Record<string, Actor>) : {};
+}
 
 // ─── Types ────────────────────────────────────────────────────
 
@@ -336,27 +345,51 @@ export async function applyServerChanges(appId: string, changes: unknown[]): Pro
 									(changeData.updatedAt as string | undefined) ??
 									(changeData.createdAt as string | undefined) ??
 									new Date().toISOString();
+								// Actor stamped by the originating device. Pre-actor clients
+								// omit the field → fall back to USER_ACTOR so the record
+								// still has a valid stamp for the Workbench to render.
+								const changeActor: Actor = change.actor ?? USER_ACTOR;
 
 								if (!existing) {
 									const ft: Record<string, string> = {};
+									const fa: Record<string, Actor> = {};
 									for (const key of Object.keys(changeData)) {
-										if (key === 'id' || key === FIELD_TIMESTAMPS_KEY) continue;
+										if (
+											key === 'id' ||
+											key === FIELD_TIMESTAMPS_KEY ||
+											key === FIELD_ACTORS_KEY ||
+											key === LAST_ACTOR_KEY
+										) {
+											continue;
+										}
 										ft[key] = recordTime;
+										fa[key] = changeActor;
 									}
 									await table.put({
 										...changeData,
 										id: recordId,
 										[FIELD_TIMESTAMPS_KEY]: ft,
+										[FIELD_ACTORS_KEY]: fa,
+										[LAST_ACTOR_KEY]: changeActor,
 									});
 								} else {
 									const localFT = readFieldTimestamps(existing);
+									const localFA = readFieldActors(existing);
 									const localUpdatedAt =
 										((existing as Record<string, unknown>).updatedAt as string | undefined) ?? '';
 									const updates: Record<string, unknown> = {};
 									const newFT: Record<string, string> = { ...localFT };
+									const newFA: Record<string, Actor> = { ...localFA };
 
 									for (const [key, val] of Object.entries(changeData)) {
-										if (key === 'id' || key === FIELD_TIMESTAMPS_KEY) continue;
+										if (
+											key === 'id' ||
+											key === FIELD_TIMESTAMPS_KEY ||
+											key === FIELD_ACTORS_KEY ||
+											key === LAST_ACTOR_KEY
+										) {
+											continue;
+										}
 										const localFieldTime = localFT[key] ?? localUpdatedAt;
 										if (recordTime >= localFieldTime) {
 											// Conflict signal: server STRICTLY wins (>) and the local
@@ -381,10 +414,13 @@ export async function applyServerChanges(appId: string, changes: unknown[]): Pro
 											}
 											updates[key] = val;
 											newFT[key] = recordTime;
+											newFA[key] = changeActor;
 										}
 									}
 									if (Object.keys(updates).length > 0) {
 										updates[FIELD_TIMESTAMPS_KEY] = newFT;
+										updates[FIELD_ACTORS_KEY] = newFA;
+										updates[LAST_ACTOR_KEY] = changeActor;
 										await table.update(recordId, updates);
 									}
 								}
@@ -392,6 +428,7 @@ export async function applyServerChanges(appId: string, changes: unknown[]): Pro
 								// Field-level LWW update — the canonical conflict-resolution path.
 								const existing = await table.get(recordId);
 								const serverFields = change.fields;
+								const changeActor: Actor = change.actor ?? USER_ACTOR;
 
 								if (!existing) {
 									// Reconstruct from fields. Other clients only see this if the
@@ -399,21 +436,27 @@ export async function applyServerChanges(appId: string, changes: unknown[]): Pro
 									// authority.
 									const record: Record<string, unknown> = { id: recordId };
 									const ft: Record<string, string> = {};
+									const fa: Record<string, Actor> = {};
 									const fallback = new Date().toISOString();
 									for (const [key, fc] of Object.entries(serverFields)) {
 										record[key] = fc.value;
 										ft[key] = fc.updatedAt ?? fallback;
+										fa[key] = changeActor;
 									}
 									record[FIELD_TIMESTAMPS_KEY] = ft;
+									record[FIELD_ACTORS_KEY] = fa;
+									record[LAST_ACTOR_KEY] = changeActor;
 									await table.put(record);
 								} else {
 									// Per-field comparison. Falls back to record-level updatedAt
 									// only for legacy records that pre-date __fieldTimestamps.
 									const localFT = readFieldTimestamps(existing);
+									const localFA = readFieldActors(existing);
 									const localUpdatedAt =
 										((existing as Record<string, unknown>).updatedAt as string | undefined) ?? '';
 									const updates: Record<string, unknown> = {};
 									const newFT: Record<string, string> = { ...localFT };
+									const newFA: Record<string, Actor> = { ...localFA };
 
 									for (const [key, fc] of Object.entries(serverFields)) {
 										const serverTime = fc.updatedAt ?? '';
@@ -439,10 +482,13 @@ export async function applyServerChanges(appId: string, changes: unknown[]): Pro
 											}
 											updates[key] = fc.value;
 											newFT[key] = serverTime;
+											newFA[key] = changeActor;
 										}
 									}
 									if (Object.keys(updates).length > 0) {
 										updates[FIELD_TIMESTAMPS_KEY] = newFT;
+										updates[FIELD_ACTORS_KEY] = newFA;
+										updates[LAST_ACTOR_KEY] = changeActor;
 										await table.update(recordId, updates);
 									}
 								}