diff --git a/packages/app/src/panels/agent-panel.tsx b/packages/app/src/panels/agent-panel.tsx
index a2c17e684..c1455c5c8 100644
--- a/packages/app/src/panels/agent-panel.tsx
+++ b/packages/app/src/panels/agent-panel.tsx
@@ -802,7 +802,7 @@ function AgentPanelBody({
             </ReanimatedAnimated.View>
           </View>
 
-          {agentId && !isArchivingCurrentAgent ? (
+          {agentId && !isArchivingCurrentAgent && !agent?.archivedAt ? (
             <AgentInputArea
               agentId={agentId}
               serverId={serverId}
diff --git a/packages/app/src/screens/workspace/workspace-agent-visibility.test.ts b/packages/app/src/screens/workspace/workspace-agent-visibility.test.ts
index 80b61dfa8..063916191 100644
--- a/packages/app/src/screens/workspace/workspace-agent-visibility.test.ts
+++ b/packages/app/src/screens/workspace/workspace-agent-visibility.test.ts
@@ -4,6 +4,7 @@ import {
   canOpenAgentTabFromRoute,
   deriveWorkspaceAgentVisibility,
   shouldPruneWorkspaceAgentTab,
+  workspaceAgentVisibilityEqual,
 } from "@/screens/workspace/workspace-agent-visibility";
 
 function makeAgent(input: {
@@ -53,7 +54,7 @@ function makeAgent(input: {
 }
 
 describe("workspace agent visibility", () => {
-  it("keeps archived agents hidden from visible list but present in workspace lookup", () => {
+  it("keeps archived agents out of activeAgentIds but present in knownAgentIds", () => {
     const workspaceId = "/repo/worktree";
     const visible = makeAgent({
       id: "visible-agent",
@@ -82,87 +83,46 @@ describe("workspace agent visibility", () => {
       workspaceId,
     });
 
-    expect(result.visibleAgents.map((agent) => agent.id)).toEqual(["visible-agent"]);
-    expect(result.lookupById.has("visible-agent")).toBe(true);
-    expect(result.lookupById.has("archived-agent")).toBe(true);
-    expect(result.lookupById.has("other-workspace-agent")).toBe(false);
+    expect(result.activeAgentIds).toEqual(new Set(["visible-agent"]));
+    expect(result.knownAgentIds.has("visible-agent")).toBe(true);
+    expect(result.knownAgentIds.has("archived-agent")).toBe(true);
+    expect(result.knownAgentIds.has("other-workspace-agent")).toBe(false);
   });
 
   it("allows explicit route open for archived agent once agents are hydrated", () => {
-    const archivedAgent = makeAgent({
-      id: "archived-agent",
-      cwd: "/repo/worktree",
-      archivedAt: new Date("2026-03-04T00:01:00.000Z"),
-    });
-    const lookup = new Map<string, Agent>([[archivedAgent.id, archivedAgent]]);
+    const knownAgentIds = new Set(["archived-agent"]);
 
     expect(
       canOpenAgentTabFromRoute({
         agentId: "archived-agent",
         agentsHydrated: true,
-        workspaceAgentLookup: lookup,
+        knownAgentIds,
       })
     ).toBe(true);
   });
 
-  it("does not prune archived agent tabs when the workspace lookup still contains the agent", () => {
-    const archivedAgent = makeAgent({
-      id: "archived-agent",
-      cwd: "/repo/worktree",
-      archivedAt: new Date("2026-03-04T00:01:00.000Z"),
-    });
-    const lookup = new Map<string, Agent>([[archivedAgent.id, archivedAgent]]);
+  it("does not prune archived agent tabs when knownAgentIds contains the agent", () => {
+    const knownAgentIds = new Set(["archived-agent"]);
 
     expect(
       shouldPruneWorkspaceAgentTab({
         agentId: "archived-agent",
         agentsHydrated: true,
-        workspaceAgentLookup: lookup,
+        knownAgentIds,
       })
     ).toBe(false);
   });
 
-  it("prunes agent tabs once agents are hydrated and the agent is missing from the workspace lookup", () => {
+  it("prunes agent tabs once agents are hydrated and the agent is missing from knownAgentIds", () => {
     expect(
       shouldPruneWorkspaceAgentTab({
         agentId: "missing-agent",
         agentsHydrated: true,
-        workspaceAgentLookup: new Map<string, Agent>(),
+        knownAgentIds: new Set<string>(),
       })
     ).toBe(true);
   });
 
-  it("sorts same-createdAt agents by lastActivityAt descending", () => {
-    const workspaceId = "/repo/worktree";
-    const createdAt = new Date("2026-03-04T00:00:00.000Z");
-    const newerActivity = makeAgent({
-      id: "newer-activity",
-      cwd: workspaceId,
-      createdAt,
-      lastActivityAt: new Date("2026-03-04T00:05:00.000Z"),
-    });
-    const olderActivity = makeAgent({
-      id: "older-activity",
-      cwd: workspaceId,
-      createdAt,
-      lastActivityAt: new Date("2026-03-04T00:01:00.000Z"),
-    });
-    const sessionAgents = new Map<string, Agent>([
-      [olderActivity.id, olderActivity],
-      [newerActivity.id, newerActivity],
-    ]);
-
-    const result = deriveWorkspaceAgentVisibility({
-      sessionAgents,
-      workspaceId,
-    });
-
-    expect(result.visibleAgents.map((agent) => agent.id)).toEqual([
-      "newer-activity",
-      "older-activity",
-    ]);
-  });
-
   it("matches workspace agents when cwd and route workspace differ only by trailing slash", () => {
     const sessionAgents = new Map<string, Agent>([
       [
@@ -179,7 +139,33 @@ describe("workspace agent visibility", () => {
       workspaceId: "/Users/moboudra/.paseo/worktrees/1luy0po7/normal-squid",
     });
 
-    expect(result.visibleAgents.map((agent) => agent.id)).toEqual(["slash-agent"]);
-    expect(result.lookupById.has("slash-agent")).toBe(true);
+    expect(result.activeAgentIds).toEqual(new Set(["slash-agent"]));
+    expect(result.knownAgentIds.has("slash-agent")).toBe(true);
+  });
+
+  describe("workspaceAgentVisibilityEqual", () => {
+    it("returns true for identical sets", () => {
+      const a = { activeAgentIds: new Set(["a", "b"]), knownAgentIds: new Set(["a", "b", "c"]) };
+      const b = { activeAgentIds: new Set(["a", "b"]), knownAgentIds: new Set(["a", "b", "c"]) };
+      expect(workspaceAgentVisibilityEqual(a, b)).toBe(true);
+    });
+
+    it("returns false when activeAgentIds differ", () => {
+      const a = { activeAgentIds: new Set(["a"]), knownAgentIds: new Set(["a"]) };
+      const b = { activeAgentIds: new Set(["b"]), knownAgentIds: new Set(["a"]) };
+      expect(workspaceAgentVisibilityEqual(a, b)).toBe(false);
+    });
+
+    it("returns false when knownAgentIds differ", () => {
+      const a = { activeAgentIds: new Set(["a"]), knownAgentIds: new Set(["a"]) };
+      const b = { activeAgentIds: new Set(["a"]), knownAgentIds: new Set(["a", "b"]) };
+      expect(workspaceAgentVisibilityEqual(a, b)).toBe(false);
+    });
+
+    it("returns true for empty sets", () => {
+      const a = { activeAgentIds: new Set<string>(), knownAgentIds: new Set<string>() };
+      const b = { activeAgentIds: new Set<string>(), knownAgentIds: new Set<string>() };
+      expect(workspaceAgentVisibilityEqual(a, b)).toBe(true);
+    });
   });
 });
diff --git a/packages/app/src/screens/workspace/workspace-agent-visibility.ts b/packages/app/src/screens/workspace/workspace-agent-visibility.ts
index db79bd9f9..5d90bf7f9 100644
--- a/packages/app/src/screens/workspace/workspace-agent-visibility.ts
+++ b/packages/app/src/screens/workspace/workspace-agent-visibility.ts
@@ -1,68 +1,66 @@
 import type { Agent } from "@/stores/session-store";
 import { normalizeWorkspaceIdentity } from "@/utils/workspace-identity";
 
-function sortAgentsByCreatedAtDescending(agents: Agent[]): Agent[] {
-  const sorted = [...agents];
-  sorted.sort((left, right) => {
-    const createdAtDelta = right.createdAt.getTime() - left.createdAt.getTime();
-    if (createdAtDelta !== 0) {
-      return createdAtDelta;
-    }
-    return right.lastActivityAt.getTime() - left.lastActivityAt.getTime();
-  });
-  return sorted;
-}
-
-function trimNonEmpty(value: string | null | undefined): string | null {
-  if (!value) {
-    return null;
-  }
-  const trimmed = value.trim();
-  return trimmed.length > 0 ? trimmed : null;
-}
-
 function normalizeWorkspaceId(value: string | null | undefined): string {
   return normalizeWorkspaceIdentity(value) ?? "";
 }
 
+export interface WorkspaceAgentVisibility {
+  activeAgentIds: Set<string>;
+  knownAgentIds: Set<string>;
+}
+
 export function deriveWorkspaceAgentVisibility(input: {
   sessionAgents: Map<string, Agent> | undefined;
   workspaceId: string;
-}): {
-  visibleAgents: Agent[];
-  lookupById: Map<string, Agent>;
-} {
+}): WorkspaceAgentVisibility {
   const { sessionAgents, workspaceId } = input;
   const normalizedWorkspaceId = normalizeWorkspaceId(workspaceId);
   if (!sessionAgents || !workspaceId) {
     return {
-      visibleAgents: [],
-      lookupById: new Map<string, Agent>(),
+      activeAgentIds: new Set<string>(),
+      knownAgentIds: new Set<string>(),
     };
   }
 
-  const lookupById = new Map<string, Agent>();
-  const visible: Agent[] = [];
+  const activeAgentIds = new Set<string>();
+  const knownAgentIds = new Set<string>();
   for (const agent of sessionAgents.values()) {
     if (normalizeWorkspaceId(agent.cwd) !== normalizedWorkspaceId) {
       continue;
     }
-    lookupById.set(agent.id, agent);
+    knownAgentIds.add(agent.id);
     if (!agent.archivedAt) {
-      visible.push(agent);
+      activeAgentIds.add(agent.id);
     }
   }
 
-  return {
-    visibleAgents: sortAgentsByCreatedAtDescending(visible),
-    lookupById,
-  };
+  return { activeAgentIds, knownAgentIds };
+}
+
+export function workspaceAgentVisibilityEqual(
+  a: WorkspaceAgentVisibility,
+  b: WorkspaceAgentVisibility,
+): boolean {
+  return setsEqual(a.activeAgentIds, b.activeAgentIds) && setsEqual(a.knownAgentIds, b.knownAgentIds);
+}
+
+function setsEqual(a: Set<string>, b: Set<string>): boolean {
+  if (a.size !== b.size) {
+    return false;
+  }
+  for (const item of a) {
+    if (!b.has(item)) {
+      return false;
+    }
+  }
+  return true;
 }
 
 export function canOpenAgentTabFromRoute(input: {
   agentId: string;
   agentsHydrated: boolean;
-  workspaceAgentLookup: Map<string, Agent>;
+  knownAgentIds: Set<string>;
 }): boolean {
   if (!input.agentId.trim()) {
     return false;
@@ -70,13 +68,13 @@ export function canOpenAgentTabFromRoute(input: {
   if (!input.agentsHydrated) {
     return true;
   }
-  return input.workspaceAgentLookup.has(input.agentId);
+  return input.knownAgentIds.has(input.agentId);
 }
 
 export function shouldPruneWorkspaceAgentTab(input: {
   agentId: string;
   agentsHydrated: boolean;
-  workspaceAgentLookup: Map<string, Agent>;
+  knownAgentIds: Set<string>;
 }): boolean {
   if (!input.agentId.trim()) {
     return false;
@@ -84,5 +82,5 @@ export function shouldPruneWorkspaceAgentTab(input: {
   if (!input.agentsHydrated) {
     return false;
   }
-  return !input.workspaceAgentLookup.has(input.agentId);
+  return !input.knownAgentIds.has(input.agentId);
 }
diff --git a/packages/app/src/screens/workspace/workspace-screen.tsx b/packages/app/src/screens/workspace/workspace-screen.tsx
index a61eb9a5c..fbecfc0f7 100644
--- a/packages/app/src/screens/workspace/workspace-screen.tsx
+++ b/packages/app/src/screens/workspace/workspace-screen.tsx
@@ -1,4 +1,5 @@
 import { memo, useCallback, useEffect, useMemo, useRef, useState } from "react";
+import { useStoreWithEqualityFn } from "zustand/traditional";
 import { useIsFocused } from "@react-navigation/native";
 import {
   ActivityIndicator,
@@ -96,6 +97,7 @@ import {
 import {
   deriveWorkspaceAgentVisibility,
   shouldPruneWorkspaceAgentTab,
+  workspaceAgentVisibilityEqual,
 } from "@/screens/workspace/workspace-agent-visibility";
 import {
   deriveWorkspacePaneState,
@@ -582,18 +584,15 @@ function WorkspaceScreenContent({
   const client = useHostRuntimeClient(normalizedServerId);
   const isConnected = useHostRuntimeIsConnected(normalizedServerId);
 
-  const sessionAgents = useSessionStore(
-    (state) => state.sessions[normalizedServerId]?.agents
-  );
-  const workspaceAgentVisibility = useMemo(
-    () =>
+  const workspaceAgentVisibility = useStoreWithEqualityFn(
+    useSessionStore,
+    (state) =>
       deriveWorkspaceAgentVisibility({
-        sessionAgents,
+        sessionAgents: state.sessions[normalizedServerId]?.agents,
         workspaceId: normalizedWorkspaceId,
       }),
-    [normalizedWorkspaceId, sessionAgents]
+    workspaceAgentVisibilityEqual,
   );
-  const workspaceAgents = workspaceAgentVisibility.visibleAgents;
 
   const terminalsQueryKey = useMemo(
     () => ["terminals", normalizedServerId, normalizedWorkspaceId] as const,
@@ -823,8 +822,6 @@ function WorkspaceScreenContent({
     return () => handler.remove();
   }, [closeToAgent, isExplorerOpen]);
 
-  const agentsById = workspaceAgentVisibility.lookupById;
-
   const persistenceKey = useMemo(
     () =>
       buildWorkspaceTabPersistenceKey({
@@ -853,7 +850,6 @@ function WorkspaceScreenContent({
   const reorderWorkspaceTabsInPane = useWorkspaceLayoutStore((state) => state.reorderTabsInPane);
   const pendingByDraftId = useCreateFlowStore((state) => state.pendingByDraftId);
   const consumedOpenIntentsRef = useRef(new Set<string>());
-  const reopenedArchivedOpenIntentsRef = useRef(new Set<string>());
   const pendingCloseTabIdsRef = useRef(new Set<string>());
   const [resolvedOpenIntentKey, setResolvedOpenIntentKey] = useState<string | null>(null);
   const currentOpenIntentKey = useMemo(
@@ -957,43 +953,6 @@ function WorkspaceScreenContent({
     }
   }, [currentOpenIntentKey, resolvedOpenIntentKey]);
 
-  useEffect(() => {
-    if (!client || !isConnected || openIntent?.kind !== "agent" || !currentOpenIntentKey) {
-      return;
-    }
-
-    const agentId = openIntent.agentId.trim();
-    if (!agentId) {
-      return;
-    }
-    if (reopenedArchivedOpenIntentsRef.current.has(currentOpenIntentKey)) {
-      return;
-    }
-
-    const agent = agentsById.get(agentId) ?? null;
-    if (!agent?.archivedAt) {
-      return;
-    }
-
-    reopenedArchivedOpenIntentsRef.current.add(currentOpenIntentKey);
-    void client.refreshAgent(agentId).catch((error) => {
-      console.warn("[WorkspaceScreen] Failed to reopen archived agent", {
-        serverId: normalizedServerId,
-        workspaceId: normalizedWorkspaceId,
-        agentId,
-        error,
-      });
-    });
-  }, [
-    agentsById,
-    client,
-    currentOpenIntentKey,
-    isConnected,
-    normalizedServerId,
-    normalizedWorkspaceId,
-    openIntent,
-  ]);
-
   useEffect(() => {
     if (!openIntent || !persistenceKey) {
       return;
@@ -1075,12 +1034,12 @@ function WorkspaceScreenContent({
       return pending?.serverId === normalizedServerId && pending.lifecycle === "active";
     });
 
-    for (const agent of workspaceAgents) {
+    for (const agentId of workspaceAgentVisibility.activeAgentIds) {
       const representedByTarget = uiTabs.some(
-        (tab) => tab.target.kind === "agent" && tab.target.agentId === agent.id
+        (tab) => tab.target.kind === "agent" && tab.target.agentId === agentId
       );
       const representedByDeterministicTabId = uiTabs.some(
-        (tab) => tab.tabId === `agent_${agent.id}`
+        (tab) => tab.tabId === `agent_${agentId}`
       );
       if (
         hasActivePendingDraftCreateInWorkspace &&
@@ -1089,7 +1048,7 @@ function WorkspaceScreenContent({
       ) {
         continue;
       }
-      ensureWorkspaceTab({ kind: "agent", agentId: agent.id });
+      ensureWorkspaceTab({ kind: "agent", agentId });
     }
     for (const terminal of terminals) {
       ensureWorkspaceTab({ kind: "terminal", terminalId: terminal.id });
@@ -1104,7 +1063,7 @@ function WorkspaceScreenContent({
         shouldPruneWorkspaceAgentTab({
           agentId: tab.target.agentId,
           agentsHydrated: hasHydratedAgents,
-          workspaceAgentLookup: agentsById,
+          knownAgentIds: workspaceAgentVisibility.knownAgentIds,
         })
       ) {
         closeWorkspaceTab(persistenceKey, tab.tabId);
@@ -1126,7 +1085,7 @@ function WorkspaceScreenContent({
     terminals,
     terminalsQuery.isSuccess,
     uiTabs,
-    workspaceAgents,
+    workspaceAgentVisibility,
   ]);
 
   const activeTabId = resolvedPaneTabState.activeTabId;
@@ -1180,7 +1139,7 @@ function WorkspaceScreenContent({
       emptyWorkspaceSeedRef.current = null;
       return;
     }
-    if (workspaceAgents.length > 0 || terminals.length > 0) {
+    if (workspaceAgentVisibility.activeAgentIds.size > 0 || terminals.length > 0) {
       emptyWorkspaceSeedRef.current = null;
       return;
     }
@@ -1202,7 +1161,7 @@ function WorkspaceScreenContent({
     persistenceKey,
     terminals.length,
     tabs.length,
-    workspaceAgents.length,
+    workspaceAgentVisibility.activeAgentIds.size,
   ]);
 
   const handleOpenFileFromExplorer = useCallback(
@@ -1485,7 +1444,7 @@ function WorkspaceScreenContent({
   const handleCopyResumeCommand = useCallback(
     async (agentId: string) => {
       if (!agentId) return;
-      const agent = sessionAgents?.get(agentId) ?? null;
+      const agent = useSessionStore.getState().sessions[normalizedServerId]?.agents?.get(agentId) ?? null;
       const providerSessionId =
         agent?.runtimeInfo?.sessionId ?? agent?.persistence?.sessionId ?? null;
       if (!agent || !providerSessionId) {
@@ -1510,7 +1469,7 @@ function WorkspaceScreenContent({
         toast.error("Copy failed");
       }
     },
-    [sessionAgents, toast]
+    [normalizedServerId, toast]
   );
 
   const handleCopyWorkspacePath = useCallback(async () => {