Lock and unlock OSX from http request.

nodejs-unlock

var applescript = require('applescript');
var http = require('http');
require('shelljs/global');

var script =
	'tell application "System Events"\n\
		if name of every process contains "ScreenSaverEngine" then \n\
			tell application "ScreenSaverEngine"\n\
				quit\n\
			end tell\n\
			delay 0.2\n\
 		else \n\
		tell application "Terminal"\n\
			do shell script "caffeinate -u -t 1"\n\
		end tell\n\
		delay 0.5\n\
		end if\n\
		keystroke "YOUR_PASSWORD"\n\
		keystroke return\n\
		get computer name of (system info)\n\
	end tell';

function onRequest(req, res) {
	if (req.url == '/unlock') {
		if (!exec('python -c \'import sys,Quartz; d=Quartz.CGSessionCopyCurrentDictionary(); sys.exit(d and d.get("CGSSessionScreenIsLocked", 0) == 0 and d.get("kCGSSessionOnConsoleKey", 0) == 1)\'')['code']){
			applescript.execString(script, function(err, rtn) {
				if (err) console.error(err);
				res.writeHead(200, { 'Content-Type': 'text/plain' });
				res.write( err ? 'something went wrong while unlocking' : 'unlocked ' + rtn );
				res.end();
			});
		} else {
			res.writeHead(200, { 'Content-Type': 'text/plain' });
			res.write('OSX isn\'t currently locked.');
			res.end();
		}
	} else if (req.url == '/lock') {
		applescript.execString('do shell script "open /System/Library/Frameworks/ScreenSaver.framework/Versions/A/Resources/ScreenSaverEngine.app"');
	} else {
		console.log('WHAT?');
		res.writeHead(200, { 'Content-Type': 'text/plain' });
		res.write('WHAT?');
		res.end();
	}
}

http.createServer(onRequest).listen(9091);

No reason to go to shell from applescript to activate screensaver.
'tell application "System Events"\n
start current screen saver\n
end tell'

And thanks for the solution around lock screen detection! 😄