diff --git a/packages/app/src/contexts/session-context.tsx b/packages/app/src/contexts/session-context.tsx
index b9d139ec7..96f2993fc 100644
--- a/packages/app/src/contexts/session-context.tsx
+++ b/packages/app/src/contexts/session-context.tsx
@@ -49,6 +49,7 @@ import { derivePendingPermissionKey, normalizeAgentSnapshot } from "@/utils/agen
 import { resolveProjectPlacement } from "@/utils/project-placement";
 import { buildDraftStoreKey } from "@/stores/draft-keys";
 import type { AttachmentMetadata } from "@/attachments/types";
+import { reconcilePreviousAgentStatuses } from "@/contexts/session-status-tracking";
 
 // Re-export types from session-store and draft-store for backward compatibility
 export type { DraftInput } from "@/stores/draft-store";
@@ -295,15 +296,10 @@ function SessionProviderInternal({ children, serverId, client }: SessionProvider
   }, []);
 
   useEffect(() => {
-    if (!sessionAgents) {
-      previousAgentStatusRef.current.clear();
-      return;
-    }
-    const nextStatuses = new Map<string, AgentLifecycleStatus>();
-    for (const nextAgent of sessionAgents.values()) {
-      nextStatuses.set(nextAgent.id, nextAgent.status);
-    }
-    previousAgentStatusRef.current = nextStatuses;
+    previousAgentStatusRef.current = reconcilePreviousAgentStatuses(
+      previousAgentStatusRef.current,
+      sessionAgents,
+    );
   }, [sessionAgents]);
 
   const hydrateWorkspaces = useCallback(
diff --git a/packages/app/src/contexts/session-status-tracking.test.ts b/packages/app/src/contexts/session-status-tracking.test.ts
new file mode 100644
index 000000000..d5e98ed3a
--- /dev/null
+++ b/packages/app/src/contexts/session-status-tracking.test.ts
@@ -0,0 +1,72 @@
+import { describe, expect, it } from "vitest";
+import type { Agent } from "@/stores/session-store";
+import { reconcilePreviousAgentStatuses } from "./session-status-tracking";
+
+function createAgent(status: Agent["status"]): Agent {
+  return {
+    serverId: "server-1",
+    id: "agent-1",
+    provider: "codex",
+    status,
+    createdAt: new Date(0),
+    updatedAt: new Date(0),
+    lastUserMessageAt: null,
+    lastActivityAt: new Date(0),
+    capabilities: {
+      supportsStreaming: true,
+      supportsSessionPersistence: true,
+      supportsDynamicModes: true,
+      supportsMcpServers: true,
+      supportsReasoningStream: true,
+      supportsToolInvocations: true,
+    },
+    currentModeId: null,
+    availableModes: [],
+    pendingPermissions: [],
+    persistence: null,
+    title: "Agent",
+    cwd: "/tmp",
+    model: null,
+    labels: {},
+    projectPlacement: null,
+  };
+}
+
+describe("reconcilePreviousAgentStatuses", () => {
+  it("preserves previously seen status for existing agents", () => {
+    const previous = new Map([["agent-1", "running" as const]]);
+    const sessionAgents = new Map([["agent-1", createAgent("idle")]]);
+
+    const result = reconcilePreviousAgentStatuses(previous, sessionAgents);
+
+    expect(result).toEqual(new Map([["agent-1", "running"]]));
+  });
+
+  it("seeds newly seen agents from the current snapshot", () => {
+    const sessionAgents = new Map([["agent-1", createAgent("idle")]]);
+
+    const result = reconcilePreviousAgentStatuses(new Map(), sessionAgents);
+
+    expect(result).toEqual(new Map([["agent-1", "idle"]]));
+  });
+
+  it("removes agents that are no longer present", () => {
+    const previous = new Map([
+      ["agent-1", "running" as const],
+      ["agent-2", "idle" as const],
+    ]);
+    const sessionAgents = new Map([["agent-1", createAgent("idle")]]);
+
+    const result = reconcilePreviousAgentStatuses(previous, sessionAgents);
+
+    expect(result).toEqual(new Map([["agent-1", "running"]]));
+  });
+
+  it("clears all tracked statuses when the session is unavailable", () => {
+    const previous = new Map([["agent-1", "running" as const]]);
+
+    const result = reconcilePreviousAgentStatuses(previous, undefined);
+
+    expect(result).toEqual(new Map());
+  });
+});
diff --git a/packages/app/src/contexts/session-status-tracking.ts b/packages/app/src/contexts/session-status-tracking.ts
new file mode 100644
index 000000000..58657ae09
--- /dev/null
+++ b/packages/app/src/contexts/session-status-tracking.ts
@@ -0,0 +1,29 @@
+import type { AgentLifecycleStatus } from "@server/shared/agent-lifecycle";
+import type { Agent } from "@/stores/session-store";
+
+export function reconcilePreviousAgentStatuses(
+  previousStatuses: Map<string, AgentLifecycleStatus>,
+  sessionAgents: Map<string, Agent> | undefined,
+): Map<string, AgentLifecycleStatus> {
+  if (!sessionAgents) {
+    return new Map();
+  }
+
+  const nextStatuses = new Map(previousStatuses);
+  const seenAgentIds = new Set<string>();
+
+  for (const agent of sessionAgents.values()) {
+    seenAgentIds.add(agent.id);
+    if (!nextStatuses.has(agent.id)) {
+      nextStatuses.set(agent.id, agent.status);
+    }
+  }
+
+  for (const agentId of nextStatuses.keys()) {
+    if (!seenAgentIds.has(agentId)) {
+      nextStatuses.delete(agentId);
+    }
+  }
+
+  return nextStatuses;
+}