diff --git a/packages/server/src/server/agent/agent-projections.ts b/packages/server/src/server/agent/agent-projections.ts
index 69f38ebde..c5a724377 100644
--- a/packages/server/src/server/agent/agent-projections.ts
+++ b/packages/server/src/server/agent/agent-projections.ts
@@ -17,12 +17,14 @@ export type { ManagedAgent };
 
 type ProjectionOptions = {
   title?: string | null;
+  createdAt?: string;
 };
 
 export function toStoredAgentRecord(
   agent: ManagedAgent,
   options?: ProjectionOptions
 ): StoredAgentRecord {
+  const createdAt = options?.createdAt ?? agent.createdAt.toISOString();
   const config = buildSerializableConfig(agent.config);
   const persistence = sanitizePersistenceHandle(agent.persistence);
 
@@ -30,7 +32,7 @@ export function toStoredAgentRecord(
     id: agent.id,
     provider: agent.provider,
     cwd: agent.cwd,
-    createdAt: agent.createdAt.toISOString(),
+    createdAt,
     updatedAt: agent.updatedAt.toISOString(),
     lastActivityAt: agent.updatedAt.toISOString(),
     lastUserMessageAt: agent.lastUserMessageAt
diff --git a/packages/server/src/server/agent/agent-registry.test.ts b/packages/server/src/server/agent/agent-registry.test.ts
index a94d8a55b..0604e32af 100644
--- a/packages/server/src/server/agent/agent-registry.test.ts
+++ b/packages/server/src/server/agent/agent-registry.test.ts
@@ -126,6 +126,30 @@ describe("AgentRegistry", () => {
     expect(persisted.config?.extra?.claude).toMatchObject({ maxThinkingTokens: 1024 });
   });
 
+  test("applySnapshot preserves original createdAt timestamp", async () => {
+    const agentId = "agent-created-at";
+    const firstTimestamp = new Date("2025-01-01T00:00:00.000Z");
+    await registry.applySnapshot(
+      createManagedAgent({ id: agentId, createdAt: firstTimestamp })
+    );
+
+    const initialRecord = await registry.get(agentId);
+    expect(initialRecord?.createdAt).toBe(firstTimestamp.toISOString());
+
+    await registry.applySnapshot(
+      createManagedAgent({
+        id: agentId,
+        createdAt: new Date("2025-02-01T00:00:00.000Z"),
+        updatedAt: new Date("2025-02-01T00:00:00.000Z"),
+        lifecycle: "running",
+      })
+    );
+
+    const updatedRecord = await registry.get(agentId);
+    expect(updatedRecord?.createdAt).toBe(firstTimestamp.toISOString());
+    expect(updatedRecord?.lastStatus).toBe("running");
+  });
+
   test("stores titles independently of snapshots", async () => {
     await registry.applySnapshot(
       createManagedAgent({
diff --git a/packages/server/src/server/agent/agent-registry.ts b/packages/server/src/server/agent/agent-registry.ts
index bcba509ea..cd84ce04b 100644
--- a/packages/server/src/server/agent/agent-registry.ts
+++ b/packages/server/src/server/agent/agent-registry.ts
@@ -109,6 +109,7 @@ export class AgentRegistry {
     const existing = this.cache.get(agent.id);
     const record = toStoredAgentRecord(agent, {
       title: existing?.title ?? null,
+      createdAt: existing?.createdAt,
     });
     this.cache.set(agent.id, record);
     await this.flush();