// API is a bit wonky right now
var xcode = require('xcode'),
    fs = require('fs'),
    projectPath = 'myproject.xcodeproj/project.pbxproj',
    myProj = xcode.project(projectPath);

// parsing is async, in a different process
myProj.parse(function (err) {
    myProj.addHeaderFile('foo.h');
    myProj.addSourceFile('foo.m');
    myProj.addFramework('FooKit.framework');
    
    fs.writeFileSync(projectPath, myProj.writeSync());
    console.log('new project written');
});