manifest.json

{
    "description": "Tries to play links in MPV",
    "manifest_version": 2,
    "name": "ff2mpv",
    "version": "3.2",

    "icons": {
        "16": "icons/icon_16x16.png",
        "32": "icons/icon_32x32.png",
        "48": "icons/icon_48x48.png",
        "64": "icons/icon_64x64.png",
        "256": "icons/icon_256x256.png"
    },

    "browser_action": {
        "default_icon": "icons/icon_48x48.png",
        "default_title": "Play the current URL in MPV"
    },

	"commands": {
		"_execute_browser_action": {
			"suggested_key": {
				"default": "Ctrl+Shift+V"
			},
			"description": "Play the current URL in mpv"
		}
	},

    "applications": {
        "gecko": {
            "id": "ff2mpv@yossarian.net",
            "strict_min_version": "50.0"
        }
    },

    "background": {
        "scripts": ["ff2mpv.js"]
    },

    "permissions": ["nativeMessaging", "contextMenus", "activeTab"]
}