diff --git a/CHANGELOG.md b/CHANGELOG.md
index 39e4f66387..237103ac5f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -68,7 +68,7 @@ Docs: https://docs.openclaw.ai
 - Gateway/Config: prevent `config.patch` object-array merges from falling back to full-array replacement when some patch entries lack `id`, so partial `agents.list` updates no longer drop unrelated agents. (#17989) Thanks @stakeswky.
 - Config/Discord: require string IDs in Discord allowlists, keep onboarding inputs string-only, and add doctor repair for numeric entries. (#18220) Thanks @thewilloftheshadow.
 - Security/Sessions: create new session transcript JSONL files with user-only (`0o600`) permissions and extend `openclaw security audit --fix` to remediate existing transcript file permissions.
-- Sessions/Maintenance: archive transcripts when pruning stale sessions, clean expired media in subdirectories, and purge old deleted transcript archives to prevent disk leaks. (#18538)
+- Sessions/Maintenance: archive transcripts when pruning stale sessions, clean expired media in subdirectories, and purge `.deleted` transcript archives after the prune window to prevent disk leaks. (#18538)
 - Infra/Fetch: ensure foreign abort-signal listener cleanup never masks original fetch successes/failures, while still preventing detached-finally unhandled rejection noise in `wrapFetchWithAbortSignal`. Thanks @Jackten.
 - Heartbeat: allow suppressing tool error warning payloads during heartbeat runs via a new heartbeat config flag. (#18497) Thanks @thewilloftheshadow.
 - Heartbeat: include sender metadata (From/To/Provider) in heartbeat prompts so model context matches the delivery target. (#18532)
diff --git a/src/config/sessions/store.pruning.e2e.test.ts b/src/config/sessions/store.pruning.e2e.test.ts
index 95ae5ee03e..a382e050a5 100644
--- a/src/config/sessions/store.pruning.e2e.test.ts
+++ b/src/config/sessions/store.pruning.e2e.test.ts
@@ -3,8 +3,8 @@ import fs from "node:fs/promises";
 import os from "node:os";
 import path from "node:path";
 import { afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
-import { clearSessionStoreCacheForTest, loadSessionStore, saveSessionStore } from "./store.js";
 import type { SessionEntry } from "./types.js";
+import { clearSessionStoreCacheForTest, loadSessionStore, saveSessionStore } from "./store.js";
 
 // Keep integration tests deterministic: never read a real openclaw.json.
 vi.mock("../config.js", () => ({
@@ -13,6 +13,8 @@ vi.mock("../config.js", () => ({
 
 const DAY_MS = 24 * 60 * 60 * 1000;
 
+const archiveTimestamp = (ms: number) => new Date(ms).toISOString().replaceAll(":", "-");
+
 let fixtureRoot = "";
 let fixtureCount = 0;
 
@@ -124,6 +126,51 @@ describe("Integration: saveSessionStore with pruning", () => {
     expect(archived).toHaveLength(1);
   });
 
+  it("cleans up archived transcripts older than the prune window", async () => {
+    mockLoadConfig.mockReturnValue({
+      session: {
+        maintenance: {
+          mode: "enforce",
+          pruneAfter: "7d",
+          maxEntries: 500,
+          rotateBytes: 10_485_760,
+        },
+      },
+    });
+
+    const now = Date.now();
+    const staleSessionId = "stale-session";
+    const store: Record<string, SessionEntry> = {
+      stale: { sessionId: staleSessionId, updatedAt: now - 30 * DAY_MS },
+      fresh: { sessionId: "fresh-session", updatedAt: now },
+    };
+
+    const staleTranscript = path.join(testDir, `${staleSessionId}.jsonl`);
+    await fs.writeFile(staleTranscript, '{"type":"session"}\n', "utf-8");
+
+    const oldArchived = path.join(
+      testDir,
+      `old-session.jsonl.deleted.${archiveTimestamp(now - 9 * DAY_MS)}`,
+    );
+    const recentArchived = path.join(
+      testDir,
+      `recent-session.jsonl.deleted.${archiveTimestamp(now - 2 * DAY_MS)}`,
+    );
+    const bakArchived = path.join(
+      testDir,
+      `bak-session.jsonl.bak.${archiveTimestamp(now - 20 * DAY_MS)}`,
+    );
+    await fs.writeFile(oldArchived, "old", "utf-8");
+    await fs.writeFile(recentArchived, "recent", "utf-8");
+    await fs.writeFile(bakArchived, "bak", "utf-8");
+
+    await saveSessionStore(storePath, store);
+
+    await expect(fs.stat(oldArchived)).rejects.toThrow();
+    await expect(fs.stat(recentArchived)).resolves.toBeDefined();
+    await expect(fs.stat(bakArchived)).resolves.toBeDefined();
+  });
+
   it("saveSessionStore skips enforcement when maintenance mode is warn", async () => {
     mockLoadConfig.mockReturnValue({
       session: {
diff --git a/src/config/sessions/store.ts b/src/config/sessions/store.ts
index 60e741dcb3..e0ff6d36ff 100644
--- a/src/config/sessions/store.ts
+++ b/src/config/sessions/store.ts
@@ -1,11 +1,15 @@
 import crypto from "node:crypto";
 import fs from "node:fs";
 import path from "node:path";
-import { acquireSessionWriteLock } from "../../agents/session-write-lock.js";
 import type { MsgContext } from "../../auto-reply/templating.js";
+import type { SessionMaintenanceConfig, SessionMaintenanceMode } from "../types.base.js";
+import { acquireSessionWriteLock } from "../../agents/session-write-lock.js";
 import { parseByteSize } from "../../cli/parse-bytes.js";
 import { parseDurationMs } from "../../cli/parse-duration.js";
-import { archiveSessionTranscripts } from "../../gateway/session-utils.fs.js";
+import {
+  archiveSessionTranscripts,
+  cleanupArchivedSessionTranscripts,
+} from "../../gateway/session-utils.fs.js";
 import { createSubsystemLogger } from "../../logging/subsystem.js";
 import {
   deliveryContextFromSession,
@@ -16,7 +20,6 @@ import {
 } from "../../utils/delivery-context.js";
 import { getFileMtimeMs, isCacheEnabled, resolveCacheTtlMs } from "../cache-utils.js";
 import { loadConfig } from "../config.js";
-import type { SessionMaintenanceConfig, SessionMaintenanceMode } from "../types.base.js";
 import { deriveSessionMetaPatch } from "./metadata.js";
 import { mergeSessionEntry, type SessionEntry } from "./types.js";
 
@@ -538,13 +541,24 @@ async function saveSessionStoreUnlocked(
         },
       });
       capEntryCount(store, maintenance.maxEntries);
+      const archivedDirs = new Set<string>();
       for (const [sessionId, sessionFile] of prunedSessionFiles) {
-        archiveSessionTranscripts({
+        const archived = archiveSessionTranscripts({
           sessionId,
           storePath,
           sessionFile,
           reason: "deleted",
         });
+        for (const archivedPath of archived) {
+          archivedDirs.add(path.dirname(archivedPath));
+        }
+      }
+      if (archivedDirs.size > 0) {
+        await cleanupArchivedSessionTranscripts({
+          directories: [...archivedDirs],
+          olderThanMs: maintenance.pruneAfterMs,
+          reason: "deleted",
+        });
       }
 
       // Rotate the on-disk file if it exceeds the size threshold.
diff --git a/src/gateway/session-utils.fs.ts b/src/gateway/session-utils.fs.ts
index 38d478ee32..c3edd8cf0a 100644
--- a/src/gateway/session-utils.fs.ts
+++ b/src/gateway/session-utils.fs.ts
@@ -1,6 +1,7 @@
 import fs from "node:fs";
 import os from "node:os";
 import path from "node:path";
+import type { SessionPreviewItem } from "./session-utils.types.js";
 import {
   resolveSessionFilePath,
   resolveSessionTranscriptPath,
@@ -10,7 +11,6 @@ import { resolveRequiredHomeDir } from "../infra/home-dir.js";
 import { hasInterSessionUserProvenance } from "../sessions/input-provenance.js";
 import { extractToolCallNames, hasToolCall } from "../utils/transcript-tools.js";
 import { stripEnvelope } from "./chat-sanitize.js";
-import type { SessionPreviewItem } from "./session-utils.types.js";
 
 type SessionTitleFields = {
   firstUserMessage: string | null;
@@ -197,6 +197,67 @@ export function archiveSessionTranscripts(opts: {
   return archived;
 }
 
+function restoreArchiveTimestamp(raw: string): string {
+  const [datePart, timePart] = raw.split("T");
+  if (!datePart || !timePart) {
+    return raw;
+  }
+  return `${datePart}T${timePart.replace(/-/g, ":")}`;
+}
+
+function parseArchivedTimestamp(fileName: string, reason: ArchiveFileReason): number | null {
+  const marker = `.${reason}.`;
+  const index = fileName.lastIndexOf(marker);
+  if (index < 0) {
+    return null;
+  }
+  const raw = fileName.slice(index + marker.length);
+  if (!raw) {
+    return null;
+  }
+  const timestamp = Date.parse(restoreArchiveTimestamp(raw));
+  return Number.isNaN(timestamp) ? null : timestamp;
+}
+
+export async function cleanupArchivedSessionTranscripts(opts: {
+  directories: string[];
+  olderThanMs: number;
+  reason?: "deleted";
+  nowMs?: number;
+}): Promise<{ removed: number; scanned: number }> {
+  if (!Number.isFinite(opts.olderThanMs) || opts.olderThanMs < 0) {
+    return { removed: 0, scanned: 0 };
+  }
+  const now = opts.nowMs ?? Date.now();
+  const reason: ArchiveFileReason = opts.reason ?? "deleted";
+  const directories = Array.from(new Set(opts.directories.map((dir) => path.resolve(dir))));
+  let removed = 0;
+  let scanned = 0;
+
+  for (const dir of directories) {
+    const entries = await fs.promises.readdir(dir).catch(() => []);
+    for (const entry of entries) {
+      const timestamp = parseArchivedTimestamp(entry, reason);
+      if (timestamp == null) {
+        continue;
+      }
+      scanned += 1;
+      if (now - timestamp <= opts.olderThanMs) {
+        continue;
+      }
+      const fullPath = path.join(dir, entry);
+      const stat = await fs.promises.stat(fullPath).catch(() => null);
+      if (!stat?.isFile()) {
+        continue;
+      }
+      await fs.promises.rm(fullPath).catch(() => undefined);
+      removed += 1;
+    }
+  }
+
+  return { removed, scanned };
+}
+
 function jsonUtf8Bytes(value: unknown): number {
   try {
     return Buffer.byteLength(JSON.stringify(value), "utf8");