diff --git a/src/agents/subagent-registry-state.test.ts b/src/agents/subagent-registry-state.test.ts
new file mode 100644
index 00000000000..13ec57427cf
--- /dev/null
+++ b/src/agents/subagent-registry-state.test.ts
@@ -0,0 +1,85 @@
+// Subagent registry state tests cover hot read caching over the persisted SQLite snapshot.
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import {
+  clearSubagentRunsReadCacheForTest,
+  getSubagentRunsSnapshotForRead,
+  persistSubagentRunsToDisk,
+} from "./subagent-registry-state.js";
+import type { SubagentRunRecord } from "./subagent-registry.types.js";
+
+const mocks = vi.hoisted(() => ({
+  loadSubagentRegistryFromSqlite: vi.fn<() => Map<string, SubagentRunRecord>>(),
+  saveSubagentRegistryToSqlite: vi.fn<(runs: Map<string, SubagentRunRecord>) => void>(),
+}));
+
+vi.mock("./subagent-registry.store.sqlite.js", () => ({
+  loadSubagentRegistryFromSqlite: mocks.loadSubagentRegistryFromSqlite,
+  saveSubagentRegistryToSqlite: mocks.saveSubagentRegistryToSqlite,
+}));
+
+function createRun(runId: string): SubagentRunRecord {
+  return {
+    runId,
+    childSessionKey: `agent:main:subagent:${runId}`,
+    requesterSessionKey: "agent:main:main",
+    requesterDisplayKey: "main",
+    task: `task ${runId}`,
+    cleanup: "keep",
+    createdAt: 1,
+    startedAt: 1,
+  };
+}
+
+describe("subagent registry state read cache", () => {
+  const previousReadDiskFlag = process.env.OPENCLAW_TEST_READ_SUBAGENT_RUNS_FROM_DISK;
+
+  beforeEach(() => {
+    vi.useFakeTimers();
+    vi.setSystemTime(1_000);
+    process.env.OPENCLAW_TEST_READ_SUBAGENT_RUNS_FROM_DISK = "1";
+    clearSubagentRunsReadCacheForTest();
+    mocks.loadSubagentRegistryFromSqlite.mockReset();
+    mocks.saveSubagentRegistryToSqlite.mockReset();
+  });
+
+  afterEach(() => {
+    clearSubagentRunsReadCacheForTest();
+    if (previousReadDiskFlag === undefined) {
+      delete process.env.OPENCLAW_TEST_READ_SUBAGENT_RUNS_FROM_DISK;
+    } else {
+      process.env.OPENCLAW_TEST_READ_SUBAGENT_RUNS_FROM_DISK = previousReadDiskFlag;
+    }
+    vi.useRealTimers();
+  });
+
+  it("reuses persisted snapshots for hot reads within the ttl", () => {
+    const firstRun = createRun("run-first");
+    const secondRun = createRun("run-second");
+    mocks.loadSubagentRegistryFromSqlite
+      .mockReturnValueOnce(new Map([[firstRun.runId, firstRun]]))
+      .mockReturnValueOnce(new Map([[secondRun.runId, secondRun]]));
+
+    expect([...getSubagentRunsSnapshotForRead(new Map()).keys()]).toEqual(["run-first"]);
+    expect([...getSubagentRunsSnapshotForRead(new Map()).keys()]).toEqual(["run-first"]);
+    expect(mocks.loadSubagentRegistryFromSqlite).toHaveBeenCalledTimes(1);
+
+    vi.advanceTimersByTime(500);
+
+    expect([...getSubagentRunsSnapshotForRead(new Map()).keys()]).toEqual(["run-second"]);
+    expect(mocks.loadSubagentRegistryFromSqlite).toHaveBeenCalledTimes(2);
+  });
+
+  it("refreshes the local read cache after successful writes", () => {
+    const firstRun = createRun("run-first");
+    const savedRun = createRun("run-saved");
+    mocks.loadSubagentRegistryFromSqlite.mockReturnValue(new Map([[firstRun.runId, firstRun]]));
+
+    expect([...getSubagentRunsSnapshotForRead(new Map()).keys()]).toEqual(["run-first"]);
+
+    persistSubagentRunsToDisk(new Map([[savedRun.runId, savedRun]]));
+
+    expect([...getSubagentRunsSnapshotForRead(new Map()).keys()]).toEqual(["run-saved"]);
+    expect(mocks.saveSubagentRegistryToSqlite).toHaveBeenCalledOnce();
+    expect(mocks.loadSubagentRegistryFromSqlite).toHaveBeenCalledTimes(1);
+  });
+});
diff --git a/src/agents/subagent-registry-state.ts b/src/agents/subagent-registry-state.ts
index ab49f8943f7..999d9623f19 100644
--- a/src/agents/subagent-registry-state.ts
+++ b/src/agents/subagent-registry-state.ts
@@ -9,9 +9,54 @@ import {
 } from "./subagent-registry.store.sqlite.js";
 import type { SubagentRunRecord } from "./subagent-registry.types.js";
 
+const SUBAGENT_RUNS_READ_CACHE_TTL_MS = 500;
+
+let persistedSubagentRunsReadCache:
+  | {
+      loadedAtMs: number;
+      runs: Map<string, SubagentRunRecord>;
+    }
+  | undefined;
+
+function cloneSubagentRunsSnapshot(
+  runs: Map<string, SubagentRunRecord>,
+): Map<string, SubagentRunRecord> {
+  return new Map([...runs.entries()].map(([runId, entry]) => [runId, structuredClone(entry)]));
+}
+
+function rememberPersistedSubagentRunsSnapshot(runs: Map<string, SubagentRunRecord>): void {
+  persistedSubagentRunsReadCache = {
+    loadedAtMs: Date.now(),
+    runs: cloneSubagentRunsSnapshot(runs),
+  };
+}
+
+function loadPersistedSubagentRunsForRead(): Map<string, SubagentRunRecord> {
+  const nowMs = Date.now();
+  if (
+    persistedSubagentRunsReadCache &&
+    nowMs >= persistedSubagentRunsReadCache.loadedAtMs &&
+    nowMs - persistedSubagentRunsReadCache.loadedAtMs < SUBAGENT_RUNS_READ_CACHE_TTL_MS
+  ) {
+    return persistedSubagentRunsReadCache.runs;
+  }
+
+  const runs = loadSubagentRegistryFromSqlite();
+  persistedSubagentRunsReadCache = {
+    loadedAtMs: nowMs,
+    runs,
+  };
+  return runs;
+}
+
+export function clearSubagentRunsReadCacheForTest(): void {
+  persistedSubagentRunsReadCache = undefined;
+}
+
 export function persistSubagentRunsToDisk(runs: Map<string, SubagentRunRecord>) {
   try {
     saveSubagentRegistryToSqlite(runs);
+    rememberPersistedSubagentRunsSnapshot(runs);
   } catch {
     // ignore persistence failures
   }
@@ -19,6 +64,7 @@ export function persistSubagentRunsToDisk(runs: Map<string, SubagentRunRecord>)
 
 export function persistSubagentRunsToDiskOrThrow(runs: Map<string, SubagentRunRecord>) {
   saveSubagentRegistryToSqlite(runs);
+  rememberPersistedSubagentRunsSnapshot(runs);
 }
 
 export function restoreSubagentRunsFromDisk(params: {
@@ -53,7 +99,9 @@ export function getSubagentRunsSnapshotForRead(
   if (shouldReadDisk) {
     try {
       // Persisted state lets other worker processes observe active runs.
-      for (const [runId, entry] of loadSubagentRegistryFromSqlite().entries()) {
+      // Cache this hot cross-process snapshot briefly; writes refresh the local
+      // cache and the TTL bounds visibility of changes from other processes.
+      for (const [runId, entry] of loadPersistedSubagentRunsForRead().entries()) {
         merged.set(runId, entry);
       }
     } catch {
diff --git a/src/agents/subagent-registry.test.ts b/src/agents/subagent-registry.test.ts
index 146665c7c4f..053209260d0 100644
--- a/src/agents/subagent-registry.test.ts
+++ b/src/agents/subagent-registry.test.ts
@@ -87,6 +87,7 @@ const mocks = vi.hoisted(() => ({
   resolveStorePath: vi.fn(() => "/tmp/test-session-store.json"),
   updateSessionStore: vi.fn(),
   emitSessionLifecycleEvent: vi.fn(),
+  clearSubagentRunsReadCacheForTest: vi.fn(),
   persistSubagentRunsToDisk: vi.fn(),
   persistSubagentRunsToDiskOrThrow: vi.fn(),
   restoreSubagentRunsFromDisk: vi.fn(() => 0),
@@ -133,6 +134,7 @@ vi.mock("../sessions/session-lifecycle-events.js", () => ({
 }));
 
 vi.mock("./subagent-registry-state.js", () => ({
+  clearSubagentRunsReadCacheForTest: mocks.clearSubagentRunsReadCacheForTest,
   getSubagentRunsSnapshotForRead: mocks.getSubagentRunsSnapshotForRead,
   persistSubagentRunsToDisk: mocks.persistSubagentRunsToDisk,
   persistSubagentRunsToDiskOrThrow: mocks.persistSubagentRunsToDiskOrThrow,
diff --git a/src/agents/subagent-registry.ts b/src/agents/subagent-registry.ts
index 78a4a239622..28e6aaf35aa 100644
--- a/src/agents/subagent-registry.ts
+++ b/src/agents/subagent-registry.ts
@@ -74,6 +74,7 @@ import {
   type RegisterSubagentRunParams,
 } from "./subagent-registry-run-manager.js";
 import {
+  clearSubagentRunsReadCacheForTest,
   getSubagentRunsSnapshotForRead,
   persistSubagentRunsToDisk,
   persistSubagentRunsToDiskOrThrow,
@@ -1255,6 +1256,7 @@ export function resetSubagentRegistryForTests(opts?: { persist?: boolean }) {
   runtimePluginsLoader.clear();
   subagentAnnounceLoader.clear();
   browserCleanupLoader.clear();
+  clearSubagentRunsReadCacheForTest();
   stopSweeper();
   sweepInProgress = false;
   restoreAttempted = false;