diff --git a/src/main/content-api-client.js b/src/main/content-api-client.js
index 671dce5..d4c0d26 100644
--- a/src/main/content-api-client.js
+++ b/src/main/content-api-client.js
@@ -22,6 +22,7 @@ import {
   API_BACKEND_AEM_API,
   API_BACKEND_DA_LIVE,
   buildPostUploadRequest,
+  DA_UNAUTHORIZED_MESSAGE,
   isValidApiBackend,
   normalizeDaPath,
 } from './content-api-shared.js';
@@ -87,7 +88,7 @@ export class ContentApiClient {
       }
       const res = await this.fetch(url, { headers, cache: 'reload' }); // eslint-disable-line no-await-in-loop
       if (res.status === 401) {
-        throw new Error('Unauthorized: invalid or expired token');
+        throw new Error(DA_UNAUTHORIZED_MESSAGE);
       }
       if (!res.ok) {
         throw await buildHttpError('GET', url, res, `List failed for ${normalized}`); // eslint-disable-line no-await-in-loop
@@ -119,7 +120,7 @@ export class ContentApiClient {
     const url = buildAemApiListUrl(org, repo, normalized);
     const res = await this.fetch(url, { headers: this.authHeader, cache: 'reload' });
     if (res.status === 401) {
-      throw new Error('Unauthorized: invalid or expired token');
+      throw new Error(DA_UNAUTHORIZED_MESSAGE);
     }
     if (!res.ok) {
       throw await buildHttpError('GET', url, res, `List failed for ${normalized}`);
@@ -146,7 +147,7 @@ export class ContentApiClient {
       : buildDaLiveSourceUrl(org, repo, normalized);
     const res = await this.fetch(url, { headers: this.authHeader, cache: 'reload' });
     if (res.status === 401) {
-      throw new Error('Unauthorized: invalid or expired token');
+      throw new Error(DA_UNAUTHORIZED_MESSAGE);
     }
     if (res.status === 404) {
       return null;
@@ -175,7 +176,7 @@ export class ContentApiClient {
       : buildDaLiveSourceUrl(org, repo, normalized);
     const res = await this.fetch(url, { headers: this.authHeader, cache: 'reload' });
     if (res.status === 401) {
-      throw new Error('Unauthorized: invalid or expired token');
+      throw new Error(DA_UNAUTHORIZED_MESSAGE);
     }
     if (res.status === 404) {
       return null;
@@ -221,7 +222,7 @@ export class ContentApiClient {
       body,
     });
     if (putRes.status === 401) {
-      throw new Error('Unauthorized: invalid or expired token');
+      throw new Error(DA_UNAUTHORIZED_MESSAGE);
     }
     if (putRes.ok) {
       return;
@@ -234,7 +235,7 @@ export class ContentApiClient {
         body: post.body,
       });
       if (postRes.status === 401) {
-        throw new Error('Unauthorized: invalid or expired token');
+        throw new Error(DA_UNAUTHORIZED_MESSAGE);
       }
       if (postRes.ok) {
         return;
@@ -262,7 +263,7 @@ export class ContentApiClient {
       headers: this.authHeader,
     });
     if (res.status === 401) {
-      throw new Error('Unauthorized: invalid or expired token');
+      throw new Error(DA_UNAUTHORIZED_MESSAGE);
     }
     if (!res.ok && res.status !== 404) {
       throw await buildHttpError('DELETE', url, res, `Delete failed for ${normalized}`);
@@ -284,7 +285,7 @@ export class ContentApiClient {
       body: JSON.stringify({ paths, forceAsync: true }),
     });
     if (res.status === 401) {
-      throw new Error('Unauthorized: invalid or expired token');
+      throw new Error(DA_UNAUTHORIZED_MESSAGE);
     }
     if (!res.ok && res.status !== 202) {
       throw await buildHttpError('POST', url, res, 'Bulk preview failed');
@@ -307,7 +308,7 @@ export class ContentApiClient {
       body: JSON.stringify({ paths, forceAsync: true }),
     });
     if (res.status === 401) {
-      throw new Error('Unauthorized: invalid or expired token');
+      throw new Error(DA_UNAUTHORIZED_MESSAGE);
     }
     if (!res.ok && res.status !== 202) {
       throw await buildHttpError('POST', url, res, 'Bulk publish failed');
@@ -327,7 +328,7 @@ export class ContentApiClient {
     const url = buildAemApiJobUrl(org, repo, topic, jobName);
     const res = await this.fetch(url, { headers: this.authHeader });
     if (res.status === 401) {
-      throw new Error('Unauthorized: invalid or expired token');
+      throw new Error(DA_UNAUTHORIZED_MESSAGE);
     }
     if (!res.ok && res.status !== 202) {
       throw await buildHttpError('GET', url, res, 'Job status failed');
diff --git a/src/main/content-api-shared.js b/src/main/content-api-shared.js
index b8bf2dc..0998c66 100644
--- a/src/main/content-api-shared.js
+++ b/src/main/content-api-shared.js
@@ -13,6 +13,18 @@
 export const API_BACKEND_DA_LIVE = 'da.live';
 export const API_BACKEND_AEM_API = 'api.aem.live';
 
+/** Thrown when da.live / api.aem.live rejects the IMS bearer token. */
+export const DA_UNAUTHORIZED_MESSAGE = 'Unauthorized: invalid or expired token';
+
+/**
+ * @param {unknown} err
+ * @returns {boolean}
+ */
+export function isDaUnauthorizedError(err) {
+  const message = err instanceof Error ? err.message : String(err);
+  return message.includes(DA_UNAUTHORIZED_MESSAGE);
+}
+
 /**
  * @param {string} backend
  * @returns {boolean}
diff --git a/src/main/index.js b/src/main/index.js
index 3d67907..716ae87 100644
--- a/src/main/index.js
+++ b/src/main/index.js
@@ -20,11 +20,15 @@ import { createWindowOptions } from './window-options.js';
 import { initAutoUpdater } from './updater.js';
 import { screenshotFilename } from './dev-config.js';
 import { toDaPath } from './aem-page-url.js';
-import { API_BACKEND_AEM_API, API_BACKEND_DA_LIVE } from './content-api-shared.js';
+import {
+  API_BACKEND_AEM_API,
+  API_BACKEND_DA_LIVE,
+  isDaUnauthorizedError,
+} from './content-api-shared.js';
 import { ContentApiClient } from './content-api-client.js';
 import { HttpRequestError } from './http-request-error.js';
 import {
-  DA_TOKEN_FILENAME, getAuthStatus, getValidToken, logout,
+  DA_TOKEN_FILENAME, clearStoredToken, getAuthStatus, getValidToken, logout,
 } from './da-auth.js';
 import {
   isSiteTokenExpired,
@@ -230,7 +234,18 @@ async function withContentClient(site, fn) {
     openBrowser: (url) => shell.openExternal(url),
   });
   const backend = site.apiBackend || API_BACKEND_DA_LIVE;
-  return fn(new ContentApiClient(accessToken, backend));
+  try {
+    return await fn(new ContentApiClient(accessToken, backend));
+  } catch (err) {
+    if (isDaUnauthorizedError(err)) {
+      await clearStoredToken(tokenPath());
+      contentDaLiveAuth?.clearCache();
+      if (mainWindow && !mainWindow.isDestroyed()) {
+        mainWindow.webContents.send('da:session-expired');
+      }
+    }
+    throw err;
+  }
 }
 
 async function createWindow() {
diff --git a/src/preload/index.cjs b/src/preload/index.cjs
index d280574..85b3481 100644
--- a/src/preload/index.cjs
+++ b/src/preload/index.cjs
@@ -29,6 +29,11 @@ contextBridge.exposeInMainWorld('aemDesktop', {
   getDaAuthStatus: () => ipcRenderer.invoke('da:auth-status'),
   loginDa: () => ipcRenderer.invoke('da:login'),
   logoutDa: () => ipcRenderer.invoke('da:logout'),
+  onDaSessionExpired: (callback) => {
+    const handler = () => callback();
+    ipcRenderer.on('da:session-expired', handler);
+    return () => ipcRenderer.removeListener('da:session-expired', handler);
+  },
   listDa: (siteId, daPath) => ipcRenderer.invoke('da:list', { siteId, daPath }),
   getDaSource: (siteId, daPath) => ipcRenderer.invoke('da:get-source', { siteId, daPath }),
   parseDocumentView: (html) => ipcRenderer.invoke('document:parse', { html }),
diff --git a/src/renderer/renderer.js b/src/renderer/renderer.js
index 685cdc9..0c45701 100644
--- a/src/renderer/renderer.js
+++ b/src/renderer/renderer.js
@@ -234,11 +234,27 @@ function hide(element) {
   element.hidden = true;
 }
 
+/** Matches {@link DA_UNAUTHORIZED_MESSAGE} in content-api-shared.js. */
+const DA_UNAUTHORIZED_SNIPPET = 'Unauthorized: invalid or expired token';
+
+/**
+ * @param {unknown} err
+ * @returns {boolean}
+ */
+function isDaUnauthorizedError(err) {
+  const message = err instanceof Error ? err.message : String(err);
+  return message.includes(DA_UNAUTHORIZED_SNIPPET);
+}
+
 /**
  * @param {string} title
  * @param {{ message?: string, xError?: string|null, detail?: string }|Error|string} error
  */
 async function showRequestErrorDialog(title, error) {
+  if (isDaUnauthorizedError(error)) {
+    await refreshAuthStatus();
+    return;
+  }
   const payload = typeof error === 'string'
     ? { message: error }
     : error;
@@ -809,6 +825,10 @@ async function loadDocumentViewForPath(daPath, pane) {
     const model = await window.aemDesktop.parseDocumentView(source.text);
     renderDocumentView(pane, model);
   } catch (err) {
+    if (isDaUnauthorizedError(err)) {
+      await refreshAuthStatus();
+      return;
+    }
     setPanePlaceholder(pane, err.message || 'Failed to load document.');
   }
 }
@@ -1008,6 +1028,10 @@ async function loadFolder(daPath) {
     state.tree.cache[daPath] = items;
     await refreshLocalBadgesForFolder(daPath);
   } catch (err) {
+    if (isDaUnauthorizedError(err)) {
+      await refreshAuthStatus();
+      return;
+    }
     if (daPath === '/') {
       state.tree.error = err.message || 'Failed to list folder';
     }
@@ -2898,6 +2922,9 @@ async function init() {
   await refreshAuthStatus();
   await loadSites();
   window.aemDesktop.onPreviewAuthRequired(handlePreviewAuthRequired);
+  window.aemDesktop.onDaSessionExpired(() => {
+    refreshAuthStatus();
+  });
   showView('home');
 }
 
diff --git a/test/content-api-shared.test.js b/test/content-api-shared.test.js
index 594c5d2..486b1de 100644
--- a/test/content-api-shared.test.js
+++ b/test/content-api-shared.test.js
@@ -14,6 +14,8 @@ import assert from 'node:assert/strict';
 import {
   API_BACKEND_DA_LIVE,
   buildPostUploadRequest,
+  DA_UNAUTHORIZED_MESSAGE,
+  isDaUnauthorizedError,
   normalizeDaPath,
   toApiRelativePath,
 } from '../src/main/content-api-shared.js';
@@ -34,3 +36,12 @@ test('buildPostUploadRequest sets filename from daPath for da.live', () => {
   );
   assert.ok(body instanceof FormData);
 });
+
+test('isDaUnauthorizedError detects API and IPC-wrapped unauthorized errors', () => {
+  assert.equal(isDaUnauthorizedError(new Error(DA_UNAUTHORIZED_MESSAGE)), true);
+  assert.equal(
+    isDaUnauthorizedError(new Error("Error invoking remote method 'da:list': Error: Unauthorized: invalid or expired token")),
+    true,
+  );
+  assert.equal(isDaUnauthorizedError(new Error('List failed for /')), false);
+});