diff --git a/xraysim/xraysim.js b/xraysim/xraysim.js
new file mode 100644
index 0000000..97f168c
--- /dev/null
+++ b/xraysim/xraysim.js
@@ -0,0 +1,221 @@
+// xraysim server
+
+var proc    = require('child_process');
+var http    = require('http')
+var fs      = require('fs')
+var Path    = require('path')
+var execSync  = require("child_process").execSync;
+var tiff = require('./UTIF')
+var binary = "./xraysim"
+
+log=console.log
+if (!fs.rmSync) fs.rmSync = function (path,options) {
+  log('Deleting '+path)
+  execSync('rm -rf '+path);
+}
+// gamma scaled by xraysim?
+function decodeTIFF(file) {
+  var data = Buffer.from(fs.readFileSync(file,'binary'),'binary');
+  // log(file,data.length,typeof data)
+  var ifd = tiff.decode(data);
+  tiff.decodeImage(data,ifd[0]);
+  if (!ifd[0].width || !ifd[0].height) throw Error("TIFF decoding failed");
+  var image = {
+    width    : ifd[0].width,
+    height   : ifd[0].height,
+    data     : new Uint32Array(new Uint8Array(ifd[0].data).buffer),
+    depth    : 1,
+    type     : 'UINT32',
+  }
+  var min,max
+  min = max = image.data[0];for(var i=1;i<image.data.length;i++) {
+    min=Math.min(min,image.data[i])
+    max=Math.max(max,image.data[i])
+  }
+  image.min=min;
+  image.max=max;
+  log(file,data.length,typeof data,image.width,image.height,image.data.length,min,max)
+  return image
+}
+// already scaled by xraysim (linear scaling)
+function decodePGM(file) {
+  var data = fs.readFileSync(file,'utf8'),
+      lines = data.split('\n');
+  if (lines[0]!='P2') return null;
+  console.log(lines.slice(0,4));
+  var shape = lines[1].split(' '),
+      width = Number(shape[0]),
+      height = Number(shape[1]),
+      range = Number(lines[2])||4095;
+  console.log('PGM',width,height,range)
+  var image = {
+    width    : width,
+    height   : height,
+    data     : new Uint16Array(width*height),
+    depth    : 1,
+    type     : 'UINT16',
+  }
+  var offset=0,size=width*height;
+  for(var i=3;i<lines.length;i++) {
+    var row = lines[i].trim().split(' ').map(Number).map(x => (x));
+    if (offset<size)
+      image.data.set(row,offset);
+    offset+=row.length;
+  }
+  image.min=0;
+  image.max=range;
+  log(file,data.length,typeof data,image.width,image.height,image.data.length,image.min,image.max)
+  return image
+}
+
+// decodeTIFF('/tmp/xray.tif')
+
+/*
+** Parse query string '?attr=val&attr=val... and return parameter record
+*/
+function parseQueryString( url ) {
+    var queryString = url.substring( url.indexOf('?') + 1 );
+    if (queryString == url) return [];
+    var params = {}, queries, temp, i, l;
+    // Split into key/value pairs
+    queries = queryString.split("&");
+    // Convert the array of strings into an object
+    for ( i = 0, l = queries.length; i < l; i++ ) {
+        temp = queries[i].split('=');
+        if (temp[1]==undefined) temp[1]='true';
+        params[temp[0]] = temp[1].replace('%20',' ');
+    }
+    return params;
+}
+function reply(response,body,headers) {
+  header={'Access-Control-Allow-Origin': '*',
+          'Access-Control-Allow-Credentials': 'true',
+          'Content-Type': 'text/plain'};
+  if (headers) { header={}; for(var p in headers) header[p]=headers[p] };
+  response.writeHead(200,header);
+  response.write(body);
+  response.end();
+}
+
+function rpc(cmd,response) {
+  switch (cmd.command) {
+    case 'sim1':
+      // one projection
+      // parts:[{name:string,material,density:number,data:stl string}]
+      var temp = fs.mkdtempSync('/tmp/');
+      for(var i in cmd.parts) {
+        var part = cmd.parts[i];
+        fs.writeFileSync(temp+'/'+part.name,part.data);
+      }
+      var scale,
+          arguments = []
+      for(var p in cmd.arguments) {
+        var arg=cmd.arguments[p];
+        switch (p) {
+          case 'energy':    arguments.push('-e '+arg); break;
+          case 'rotate':    arguments.push('-r '+arg); break;
+          case 'Rotate':    arguments.push('-R '+arg.join(' ')); break;
+          case 'sourcePos'     : arguments.push('-s '+arg,join(' ')); break;
+          case 'detectorPos'   : arguments.push('-d '+arg,join(' ')); break;
+          case 'detectorUpVec' : arguments.push('-D '+arg.join(' ')); break;
+          case 'width':     arguments.push('-w '+arg); break;
+          case 'height':    arguments.push('-h '+arg); break;
+          case 'pixelSize': arguments.push('-p '+arg); break;
+          case 'scale'    : scale=arg; arguments.push('-S '+arg.join(' ')); break;
+        }
+      }
+      if (!scale) arguments.push('-o '+temp+'/xray.tif'); // gamma scaled
+      else        arguments.push('-o '+temp+'/xray.pgm'); // linear scaled
+      
+      for(var i in cmd.parts) {
+        var part = cmd.parts[i];
+        arguments.push('-u '+part.density);
+        arguments.push(temp+'/'+part.name);
+      }
+      var stdout = execSync(binary+' '+arguments.join(' '));
+      log(stdout.toString())
+      try {
+        if (!scale) {
+          var image  = decodeTIFF(temp+'/xray.tif');
+          image.data = Array.from(image.data)
+        } else {
+          var image  = decodePGM(temp+'/xray.pgm',scale);
+          image.data = Array.from(image.data)        
+        }
+      } catch (e) {
+        log(e)
+      }
+      fs.rmSync(temp, { recursive: true, force: true });
+      var body = JSON.stringify({
+        image  : image,
+        stdout : stdout.toString()   
+      });
+      log(body.length)
+      if (response) reply(response,body)
+      break;
+  }
+}
+
+function server (config) {
+  var webSrv = http.createServer(function (request,response) {
+    var body,header,sep,query,res,now,path,
+        rid = request.connection.remoteAddress+':'+request.connection.remotePort;
+    if (request.url.length) 
+      query=parseQueryString(request.url);
+    else 
+      query={}
+
+    path=request.url.match(/\/([^?]+)/);
+    if (path) path=path[1];
+    switch (request.method) {
+      case 'GET':
+        break;
+      case 'POST':
+        body = '';
+        request.on('data', function (chunk) {
+          body = body + chunk;
+        });
+        request.on('end', function () {
+          try {
+            var cmd = JSON.parse(body);
+            rpc(cmd,response)
+          } catch (e) {
+            log(e)
+          }  
+        })
+        break;
+    }
+  })
+
+  webSrv.on("connection", function (socket) {
+      // socket.setNoDelay(true);
+  });
+
+  webSrv.on("error", function (err) {
+    log(err)
+    process.exit();
+  });
+
+  webSrv.listen(config.port,function (err) {
+    log('HTTP Service started (http://localhost:'+config.port+')');
+  });
+}
+
+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 : 100,
+    }
+  }
+  log(JSON.stringify(req).length)
+  rpc(req)
+}
+
+server({
+  port:6666
+})