<div id="pageData-name" class="pageData">Permission Warnings</div> <div id="pageData-showTOC" class="pageData">true</div> <!-- NOTE: When this doc is updated, the online help should also be updated: http://www.google.com/support/chrome/bin/answer.py?hl=en&answer=186213 We should periodically look at http://src.chromium.org/viewvc/chrome/trunk/src/chrome/app/generated_resources.grd?view=markup to make sure that we're covering all messages. Search for IDS_EXTENSION_PROMPT_WARNING (e.g. IDS_EXTENSION_PROMPT_WARNING_BROWSING_HISTORY). --> <p> To use most chrome.* APIs and extension capabilities, your extension must declare its intent in the <a href="manifest.html">manifest</a>, often in the "permissions" field. Some of these declarations result in a warning when a user installs your extension. </p> <p> When you autoupdate your extension, the user might see another warning if the extension requests new permissions. These new permissions might be new APIs that your extension uses, or they might be new websites that your extension needs access to. </p> <h2 id="examples"> Examples of permission warnings </h2> <p> Here's a typical dialog that a user might see when installing an extension: </p> <img src="images/perms-hw1.png" width="410" height="193" alt="Permission warning: 'It can access: Your data on api.flickr.com'" /> <p> The warning about access to data on api.flickr.com is caused by the following lines in the extension's manifest: </p> <pre> "permissions": [ <b>"http://api.flickr.com/"</b> ], </pre> <p class="note"> <b>Note:</b> You don't see permission warnings when you load an unpacked extension. You get permission warnings only when you install an extension from a <code>.crx</code> file. </p> <p> If you add a permission to the extension when you autoupdate it, the user might see a new permission warning. For example, assume you add a new site and the "tabs" permission to the previous example: </p> <pre> "permissions": [ "http://api.flickr.com/", <b>"http://*.flickr.com/", "tabs"</b> ], </pre> <p> When the extension autoupdates, the increased permissions cause the extension to be disabled until the user re-enables it. Here's the warning the user sees: </p> <img src="images/perms-hw2-disabled.png" width="814" height="30" alt="Warning text: 'The newest version of the extension Hello World requires more permissions, so it has been disabled. [Re-enable].'" /> <p> Clicking the Re-enable button brings up the following warning: </p> <img src="images/perms-hw2.png" width="412" height="220" alt="Permission warning: 'It can access: Your data on api.flickr.com and flickr.com; Your browsing history'" /> <h2 id="warnings"> Warnings and their triggers </h2> <p> It can be surprising when adding a permission such as "tabs" results in the seemingly unrelated warning that the extension can access your browsing history. The reason for the warning is that although the <code>chrome.tabs</code> API might be used only to open new tabs, it can also be used to see the URL that's associated with every newly opened tab (using their <a href="tabs.html#type-Tab">Tab</a> objects). </p> <p class="note"> <b>Note:</b> As of Google Chrome 7, you no longer need to specify the "tabs" permission just to call <code>chrome.tabs.create()</code> or <code>chrome.tabs.update()</code>. </p> <p> The following table lists the warning messages that users can see, along with the manifest entries that trigger them. </p> <p> <table> <tr> <th>Warning message</th> <th>Manifest entry that causes it</th> <th>Notes</th> </tr> <tr> <td style="font-weight:bold"> <!-- IDS_EXTENSION_PROMPT_WARNING_FULL_ACCESS --> All data on your computer and the websites you visit </td> <td> "plugins" </td> <td> The "plugins" permission is required by <a href="npapi.html">NPAPI plugins</a>. </td> </tr> <tr> <td style="font-weight:bold"> <!-- IDS_EXTENSION_PROMPT_WARNING_BOOKMARKS --> Your bookmarks </td> <td> "bookmarks" permission </td> <td> The "bookmarks" permission is required by the <a href="bookmarks.html"><code>chrome.bookmarks</code></a> module. </td> </tr> <tr> <td style="font-weight:bold"> <!-- IDS_EXTENSION_PROMPT_WARNING_BROWSING_HISTORY --> Your browsing history </td> <td> <!-- HasEffectiveBrowsingHistoryPermission --> "history" or "tabs" permission </td> <td> <p> The "tabs" permission is required by the <a href="tabs.html"><code>chrome.tabs</code></a> and <a href="windows.html"><code>chrome.windows</code></a> modules. </p> <p> The "history" permission is required by <a href="history.html"><code>chrome.history</code></a>. </p> <p> Adding "tabs" to an existing extension that already has "history", or vice versa, doesn't cause a warning when the extension is autoupdated. </p> </td> </tr> <tr> <td style="font-weight:bold"> <!-- IDS_EXTENSION_PROMPT_WARNING_ALL_HOSTS --> Your data on all websites </td> <td> <!-- HasEffectiveAccessToAllHosts() --> Any of the following: <ul> <li> "proxy" permission (experimental) </li> <li> A match pattern in the "permissions" field that matches all hosts </li> <li> A "content_scripts" field with a "matches" entry that matches all hosts </li> </ul> </td> <td> <p> The "proxy" permission is required by the <a href="http://code.google.com/chrome/extensions/dev/experimental.proxy.html">experimental proxy</a> module. </p> <p> Any of the following URLs match all hosts: </p> <ul> <li> <code>http://*/*</code> </li> <li> <code>https://*/*</code> </li> <li> <code>*://*/*</code> </li> <li> <code><all_urls></code> </li> </ul> </td> </tr> <tr> <td style="font-weight:bold"> <!-- IDS_EXTENSION_PROMPT_WARNING_?_HOST --> <!-- IDS_EXTENSION_PROMPT_WARNING_4_OR_MORE_HOSTS --> Your data on <em>{list of websites}</em> </td> <td> A match pattern in the "permissions" field that specifies one or more hosts, but not all hosts </td> <td> <p> Up to 3 sites are listed by name. Subdomains aren't treated specially. For example, <code>a.com</code> and <code>b.a.com</code> are listed as different sites. </p> <p> On autoupdate, the user sees a permission warning if the extension adds or changes sites. For example, going from <code>a.com,b.com</code> to <code>a.com,b.com,c.com</code> triggers a warning. Going from <code>b.a.com</code> to <code>a.com</code>, or vice versa, also triggers a warning. </p> </td> </tr> <tr> <td style="font-weight:bold"> <!-- IDS_EXTENSION_PROMPT_WARNING_MANAGEMENT --> Your list of installed apps, extensions, and themes <br /> <span style="font-weight:normal; font-style:italic">or</span> <br /> Manage themes, extensions, and apps <!-- PENDING: remove "Manage...apps" alternative message once the fix is out on stable channel --> <!-- See http://crbug.com/67859 --> </td> <td> "management" permission </td> <td> The "management" permission is required by the <a href="management.html"><code>chrome.management</code></a> module. </td> </tr> <tr> <td style="font-weight:bold"> <!-- IDS_EXTENSION_PROMPT_WARNING_GEOLOCATION --> Your physical location </td> <td> "geolocation" permission </td> <td> Allows the extension to use the proposed HTML5 <a href="http://dev.w3.org/geo/api/spec-source.html">geolocation API</a> without prompting the user for permission. </td> </tr> </table> </p> <h2 id="nowarning"> Permissions that don't cause warnings </h2> <p> The following permissions don't result in a warning: </p> <ul> <li>"chrome://favicon/"</li> <li>"contextMenus"</li> <li>"cookies"</li> <li>"experimental"</li> <li>"idle"</li> <li>"notifications"</li> <li>"unlimitedStorage"</li> </ul> <h2 id="test"> Testing permission warnings </h2> <p> If you'd like to see exactly which warnings your users will get, <a href="packaging.html">package your extension</a> into a <code>.crx</code> file, and install it. </p> <p> To see the warnings users will get when your extension is autoupdated, you can go to a little more trouble and set up an autoupdate server. To do this, first create an update manifest and point to it from your extension, using the "update_url" key (see <a href="autoupdate.html">Autoupdating</a>). Next, <a href="packaging.html">package the extension</a> into a new <code>.crx</code> file, and install the app from this <code>.crx</code> file. Now, change the extension's manifest to contain the new permissions, and <a href="packaging.html#update">repackage the extension</a>. Finally, update the extension (and all other extensions that have outstanding updates) by clicking the <b>chrome://extensions</b> page's <b>Update extensions now</b> button. </p>