sessions

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Use the sessions API to list, and restore, tabs and windows that have been closed while the browser has been running.

The {{WebExtAPIRef("sessions.getRecentlyClosed()")}}  function returns an array of {{WebExtAPIRef("tabs.Tab")}}  and {{WebExtAPIRef("windows.Window")}}  objects, representing tabs and windows that have been closed since the browser was running, up to the maximum defined in {{WebExtAPIRef("sessions.MAX_SESSION_RESULTS")}} .

You can then restore a window or tab using the {{WebExtAPIRef("sessions.restore()")}}  function. Restoring doesn’t just reopen the tab: it also restores the tab’s navigation history so the back/forward buttons will work.

This API also provides a group of functions that enable an extension to store additional state associated with a tab or a window. Then, if the tab or window is closed and subsequently restored, the extension can retrieve the state. For example, a tab grouping extension might use this to remember which group a tab is in, so as to restore it into the right group if the user restores the tab.

To use the sessions API you must have the “sessions” API permission.

Types

• {{WebExtAPIRef("sessions.Filter")}} 
  • : Enables you to restrict the number of {{WebExtAPIRef("sessions.Session", "Session")}}  objects returned by a call to {{WebExtAPIRef("sessions.getRecentlyClosed()")}} .
• {{WebExtAPIRef("sessions.Session")}} 
  • : Represents a tab or window that the user has closed in the current browsing session.

Properties

• {{WebExtAPIRef("sessions.MAX_SESSION_RESULTS")}} 
  • : The maximum number of sessions that will be returned by a call to sessions.getRecentlyClosed().

Functions

• {{WebExtAPIRef("sessions.forgetClosedTab()")}} 
  • : Removes a closed tab from the browser’s list of recently closed tabs.
• {{WebExtAPIRef("sessions.forgetClosedWindow()")}} 
  • : Removes a closed window from the browser’s list of recently closed windows.
• {{WebExtAPIRef("sessions.getRecentlyClosed()")}} 
  • : Returns an array of {{WebExtAPIRef("sessions.Session", "Session")}}  objects, representing windows and tabs that were closed in the current browsing session (that is: the time since the browser was started).
• {{WebExtAPIRef("sessions.restore()")}} 
  • : Restores a closed tab or window.
• {{WebExtAPIRef("sessions.setTabValue()")}} 
  • : Store a key/value pair associated with a given tab.
• {{WebExtAPIRef("sessions.getTabValue()")}} 
  • : Retrieve a previously stored value for a given tab, given its key.
• {{WebExtAPIRef("sessions.removeTabValue()")}} 
  • : Remove a key/value pair from a given tab.
• {{WebExtAPIRef("sessions.setWindowValue()")}} 
  • : Store a key/value pair associated with a given window.
• {{WebExtAPIRef("sessions.getWindowValue()")}} 
  • : Retrieve a previously stored value for a given window, given its key.
• {{WebExtAPIRef("sessions.removeWindowValue()")}} 
  • : Remove a key/value pair from a given window.

Events

• {{WebExtAPIRef("sessions.onChanged")}} 
  • : Fired when a tab or window is closed.

Browser compatibility

{{Compat}} 

{{WebExtExamples("h2")}} 

[!NOTE] This API is based on Chromium’s chrome.sessions API.