diff --git a/xraysim/xraysim.run.js b/xraysim/xraysim.run.js
new file mode 100644
index 0000000..c442fb7
--- /dev/null
+++ b/xraysim/xraysim.run.js
@@ -0,0 +1,171 @@
+var http    = require('http'),
+    path    = require('path'),
+    fs      = require('fs');
+print=console.log
+
+var URL = 'localhost:6666'
+
+function POST(url, data, cb) {
+  var params,headers;
+  if (data && data.params && data.data != undefined) {
+    params=data.params;
+    headers=data.headers;
+    data=data.data;
+  }
+  var ishttps= url.match(/https:/);
+  url=url.replace(/http[s]?:\/\//,'');
+  var parts = url.split(':'),
+      path  = parts[0].split('/').slice(1).join('/'),
+      host  = parts[0].split('/')[0],
+      port  = parts[1]||(ishttps?'443':'80');
+  if (params) {
+        var o=params,sep='';
+        params='/?';
+        for(var p in o) {
+          params = params + sep + p + '='+o[p];
+          sep='&';
+        } 
+  } else params='';
+  var post_data = typeof data == 'string'?data:JSON.stringify(data);
+  var post_options = {
+      host: host,
+      port: port,
+      path: '/'+path+params,
+      method: 'POST',
+      keepAlive: true,
+      headers: headers || {
+          'Content-Type': 'application/json', // ?? 'application/x-www-form-urlencoded',
+          // 'Content-Length': Buffer.byteLength(post_data)
+          'Content-Length': post_data.length,
+      }
+  };
+  // console.log('POST', post_options,post_data)
+  var post_req = (ishttps?https:http).request(post_options, function(res) {
+      res.setEncoding('utf8');
+      
+      var data='';
+      res.on('data', function (chunk) {
+        data += chunk;
+        // console.log('Response: ' + chunk);
+      });
+      res.on('end', function () {
+        try {
+          var result=JSON.parse(data);
+          // console.log('POST: ',result);
+        } catch (e) { print(data); result=e; }
+        if (cb) cb(result);
+      });
+  });
+  post_req.on('error',function (err) {
+    if (cb) cb(err); else console.log(url,err)
+  });
+  post_req.setNoDelay();
+  // console.log('POST: ',post_data);
+  // post the data
+  post_req.write(post_data);
+  post_req.end();
+}
+
+function test() {
+  var req = {
+    command : 'sim1',
+    parts : [
+      {name:'plate1metal',density:5,data:fs.readFileSync('../demo3/plate1_metal.stl','utf8') },
+      {name:'plate1fibre',density:2,data:fs.readFileSync('../demo3/plate1_fibre.stl','utf8') },
+    ],
+    arguments : {
+      energy : 0.1,
+      width : 1000,
+      height : 1000
+    }
+  }
+  var body = JSON.stringify(req)
+  print(body.length)
+  POST(URL,body, function (result) {
+    if (result instanceof Error) return print(result);
+    var image = result.image
+    image.data=new Uint32Array(image.data);
+    print(image)
+  })
+}
+
+function savePGM(name, image, range) {
+  var header = 'P2\n'+image.width+' '+image.height+'\n'+range+'\n',
+      data = [],
+      min  = image.min,
+      max  = image.max,
+      scale  = range/(image.max-image.min)
+  // auto scale
+  for (var i=0;i<image.data.length;) {
+    var row = []
+    for(var k=0;k<8;k++) {
+      row.push(((image.data[i]-min)*scale)|0)
+      i++;
+      if (i==image.data.length) break;
+    }
+    data.push(row.join(' '))
+  }
+  fs.writeFileSync(name,header+data.join('\n'),"utf8");
+}
+
+function usage () {
+  print("usage: xraysim [-ip URL] [-s(ourcePos) x y z] [-d(etPos) x y z] [-D(etUpVec) x y z");
+  print("               [-S(scale) min max range (linear)] [-e(nergy) MeV]");
+  print("               [-p pixelsize] [-w(idth) pixels] [-h(eight) pixels] ");
+  print("               [-r(otate-z) degree] [-R(otate) x y z]");
+  print("               [-o out.pgm|tif(f)]");
+  print("               [-u density g/cm3] file.stl [-u density file2.stl ..]");
+}
+function sim() {
+  var arguments = {},
+      densities = [],
+      output = 'xray.pgm',
+      parts = []
+  for(var i=2;i<process.argv.length;i++) {
+    var arg=process.argv[i];
+    switch (arg) {
+      case '-help': return usage();
+      case '-e': arguments.energy=process.argv[++i]; break;
+      case '-r': arguments.rotate=process.argv[++i]; break;
+      case '-R': arguments.Rotate = [process.argv[++i],process.argv[++i],process.argv[++i]]; break; 
+      case '-w': arguments.width=process.argv[++i]; break;
+      case '-h': arguments.height=process.argv[++i]; break;
+      case '-u': densities.push(process.argv[++i]); break;
+      case '-p': arguments.pixelSize=process.argv[++i]; break;
+      case '-o': output=process.argv[++i]; break;
+      case '-ip': URL=process.argv[++i]; break;
+      case '-s': arguments.sourcePos   = [process.argv[++i],process.argv[++i],process.argv[++i]]; break; 
+      case '-d': arguments.detectorPos = [process.argv[++i],process.argv[++i],process.argv[++i]]; break; 
+      case '-D': arguments.detectorUpVec = [process.argv[++i],process.argv[++i],process.argv[++i]]; break; 
+      case '-S': arguments.scale         = [process.argv[++i],process.argv[++i],process.argv[++i]]; break; 
+      default:
+        if (arg[0]!='-') {
+          parts.push(arg);
+        }
+    }
+  }
+  if (parts.length > 1 && parts.length != densities.length) throw "Parts and densities have different lengths";
+  for(var i=0;i<parts.length;i++) {
+    parts[i]={
+      name:path.basename(parts[i]),
+      density:densities[i]||1,
+      data:fs.readFileSync(parts[i],'utf8')
+    }
+  }
+  var req = {
+    command:'sim1',
+    parts:parts,
+    arguments:arguments
+  }
+  var body = JSON.stringify(req)
+  print('sending request body',body.length)
+  POST(URL,body, function (result) {
+    if (result instanceof Error) return print(result);
+    print(result.stdout)
+    var image = result.image
+    image.data=new Uint32Array(image.data);
+    // print(image)
+    savePGM(output,image,(req.arguments.scale && req.arguments.scale[2]) || 65535)
+  })
+}
+sim()