chrome.commands

# Manifest

You must have a "manifest_version" of at least 2 to use this API.

# Usage

The Commands API allows extension developers to define specific commands, and bind them to a default key combination. Each command an extension accepts must be declared as properties of the "commands" object in the extension's manifest.

The property key is used as the command's name. Command objects can take two properties.

suggested_key

An optional property that declares default keyboard shortcuts for the command. If omitted, the command will be unbound. This property can either take a string or an object value.

• A string value specifies the default keyboard shortcut that should be used across all platforms.

• An object value allows the extension developer to customize the keyboard shortcut for each platform. When providing platform-specific shortcuts, valid object properties are default, chromeos, linux, mac, and windows.

See Key combination requirements for additional details.

description

A string used to provide the user with a short description of the command's purpose. This string appears in extension keyboard shortcut management UI. Descriptions are required for standard commands, but are ignored for Action commands.

An extension can have many commands, but may specify at most four suggested keyboard shortcuts. The user can manually add more shortcuts from the chrome://extensions/shortcuts dialog.

# Supported Keys

The following keys are usable command shortcuts. Key definitions are case sensitive. Attempting to load an extension with an incorrectly cased key will result in a manifest parse error at installation time.

Alpha keys

A … Z

Numeric keys

0 … 9

Standard key strings

General–Comma, Period, Home, End, PageUp, PageDown, Space, Insert, Delete

Arrow keys–Up, Down, Left, Right

Media Keys–MediaNextTrack, MediaPlayPause, MediaPrevTrack, MediaStop

Modifier key strings

Ctrl, Alt, Shift, MacCtrl (macOS only), Command (macOS only), Search (ChromeOS only)

# Key combination requirements

• Extension command shortcuts must include either Ctrl or Alt.

  • Modifiers cannot be used in combination with Media Keys.

• On macOS Ctrl is automatically converted into Command.

  • To use the Control key on macOS, replace Ctrl with MacCtrl when defining the "mac" shortcut.

  • Using MacCtrl in the combination for another platform will cause a validation error and prevent the extension from being installed.

• Shift is an optional modifier on all platforms.

• Search is an optional modifier exclusive to ChromeOS.

• Certain operating system and Chrome shortcuts (e.g. window management) always take priority over Extension command shortcuts and can not be overwritten.

# Handling command events

{
  "name": "My extension",
  ...
  "commands": {
    "run-foo": {
      "suggested_key": {
        "default": "Ctrl+Shift+Y",
        "mac": "Command+Shift+Y"
      },
      "description": "Run \"foo\" on the current page."
    },
    "_execute_action": {
      "suggested_key": {
        "windows": "Ctrl+Shift+Y",
        "mac": "Command+Shift+Y",
        "chromeos": "Ctrl+Shift+U",
        "linux": "Ctrl+Shift+J"
      }
    }
  },
  ...
}

In your background page, you can bind a handler to each of the commands defined in the manifest using onCommand.addListener. For example:

chrome.commands.onCommand.addListener((command) => {
  console.log(`Command: ${command}`);
});

# Action commands

The _execute_action (Manifest V3), _execute_browser_action (Manifest V2), and _execute_page_action (Manifest V2) commands are reserved for the action of trigger your action, browser action, or page action respectively. These commands do not dispatch command.onCommand events like standard commands.

If you need to take action based on your popup opening, consider listening for a DOMContentLoaded event inside your popup's JavaScript.

# Scope

By default, commands are scoped to the Chrome browser. This means that when the browser does not have focus, command shortcuts are inactive. Beginning in Chrome 35, extension developers can optionally mark a command as "global". Global commands also work while Chrome does not have focus.

Keyboard shortcut suggestions for global commands are limited to Ctrl+Shift+[0..9]. This is a protective measure to minimize the risk of overriding shortcuts in other applications since if, for example, Alt+P were to be allowed as global, the keyboard shortcut for opening a print dialog might not work in other applications.

End users are free to remap global commands to their preferred key combination using the UI exposed at chrome://extensions/shortcuts.

Example:

{
  "name": "My extension",
  ...
  "commands": {
    "toggle-feature-foo": {
      "suggested_key": {
        "default": "Ctrl+Shift+5"
      },
      "description": "Toggle feature foo",
      "global": true
    }
  },
  ...
}

# Examples

The following examples flex the core functionality of the Commands API.

# Basic command

Commands allow extensions to map logic to keyboard shortcuts that can be invoked by the user. At its most basic, a command only requires a command declaration in the extension's manifest and a listener registration as shown in the following example.

// manifest.json
{
  "name": "Command demo - basic",
  "version": "1.0",
  "manifest_version": 3,
  "background": {
    "service_worker": "background.js"
  },
  "commands": {
    "inject-script": {
      "suggested_key": "Ctrl+Shift+Y",
      "description": "Inject a script on the page"
    }
  }
}

// background.js
chrome.commands.onCommand.addListener((command) => {
  console.log(`Command "${command}" triggered`);
});

# Action command

As described in the Usage section, you can also map a command to an extension's action, browser action, or page action. The following example injects a content script that shows an alert on the current page when the user either clicks the extension's action or triggers the keyboard shortcut.

// manifest.json
{
  "name": "Commands demo - action invocation",
  "version": "1.0",
  "manifest_version": 3,
  "background": {
    "service_worker": "background.js"
  },
  "permissions": ["activeTab", "scripting"],
  "action": {},
  "commands": {
    "_execute_action": {
      "suggested_key": {
        "default": "Ctrl+U",
        "mac": "Command+U"
      }
    }
  }
}

// background.js
chrome.action.onClicked.addListener((tab) => {
  chrome.scripting.executeScript({
    target: {tabId: tab.id},
    func: contentScriptFunc,
    args: ['action'],
  });
});

function contentScriptFunc(name) {
  alert(`"${name}" executed`);
}

// This callback WILL NOT be called for "_execute_action"
chrome.commands.onCommand.addListener((command) => {
  console.log(`Command "${command}" called`);
});

# Verify commands registered

If an extension attempts to register a shortcut that is already used by another extension, the second extension's shortcut will not register as expected. You can provide a more robust end user experience by anticipating this possibility and checking for collisions at install time.

// background.js
chrome.runtime.onInstalled.addListener((reason) => {
  if (reason === chrome.runtime.OnInstalledReason.INSTALL) {
    checkCommandShortcuts();
  }
});

// Only use this function during the initial install phase. After
// installation the user may have intentionally unassigned commands.
function checkCommandShortcuts() {
  chrome.commands.getAll((commands) => {
    let missingShortcuts = [];

    for (let {name, shortcut} of commands) {
      if (shortcut === '') {
        missingShortcuts.push(name);
      }
    }

    if (missingShortcuts.length > 0) {
      // Update the extension UI to inform the user that one or more
      // commands are currently unassigned.
    }
  });
}