diff --git a/lib/go/camli/httputil/httputil.go b/lib/go/camli/httputil/httputil.go
index 277170d6b..a0c3926d2 100644
--- a/lib/go/camli/httputil/httputil.go
+++ b/lib/go/camli/httputil/httputil.go
@@ -45,14 +45,21 @@ func ReturnJson(conn http.ResponseWriter, data interface{}) {
 	conn.Header().Set("Content-Type", "text/javascript")
 
 	if m, ok := data.(map[string]interface{}); ok {
+		statusCode := 0
+		if t, ok := m["error"].(string); ok && len(t) > 0 {
+			statusCode = http.StatusInternalServerError
+		}
 		if t, ok := m["errorType"].(string); ok {
 			switch t {
 			case "server":
-				conn.WriteHeader(http.StatusInternalServerError)
+				statusCode = http.StatusInternalServerError
 			case "input":
-				conn.WriteHeader(http.StatusBadRequest)
+				statusCode = http.StatusBadRequest
 			}
 		}
+		if statusCode != 0 {
+			conn.WriteHeader(statusCode)
+		}
 	}
 
 	bytes, err := json.MarshalIndent(data, "", "  ")
diff --git a/server/go/camlistored/ui.go b/server/go/camlistored/ui.go
index 68ad03c95..75d4064d2 100644
--- a/server/go/camlistored/ui.go
+++ b/server/go/camlistored/ui.go
@@ -17,7 +17,6 @@ limitations under the License.
 package main
 
 import (
-	"bytes"
 	"fmt"
 	"http"
 	"io"
@@ -207,48 +206,6 @@ func (ui *UIHandler) serveDiscovery(rw http.ResponseWriter, req *http.Request) {
 	}
 }
 
-func (ui *UIHandler) serveUploadHelper(rw http.ResponseWriter, req *http.Request) {
-	if ui.Storage == nil {
-		http.Error(rw, "No BlobRoot configured", 500)
-		return
-	}
-	var buf bytes.Buffer
-	defer io.Copy(rw, &buf)
-
-	fmt.Fprintf(&buf, "<pre>\n")
-
-	mr, err := req.MultipartReader()
-	if err != nil {
-		fmt.Fprintf(&buf, "multipart reader: %v", err)
-		return
-	}
-
-	for {
-		part, err := mr.NextPart()
-		if err == os.EOF {
-			break
-		}
-		if err != nil {
-			buf.Reset()
-			http.Error(rw, "Multipart error: "+err.String(), 500)
-			break
-		}
-		fileName := part.FileName()
-		if fileName == "" {
-			continue
-		}
-		get, _ := http.ParseQuery(req.URL.RawQuery)
-		writeFn := schema.WriteFileFromReader
-		if len(get["rollsum"]) == 1 && get["rollsum"][0] == "1" {
-			writeFn = schema.WriteFileFromReaderRolling
-		}
-		br, err := writeFn(ui.Storage, fileName, part)
-
-		fmt.Fprintf(&buf, "filename=%q, formname=%q, br=<a href='./?b=%s'>%s</a>, err=%v\n", part.FileName(), part.FormName(), br, br, err)
-
-	}
-}
-
 func (ui *UIHandler) storageSeekFetcher() (blobref.SeekFetcher, os.Error) {
 	return blobref.SeekerFromStreamingFetcher(ui.Storage)
 }
diff --git a/server/go/camlistored/ui/camli.js b/server/go/camlistored/ui/camli.js
index 11f7fa6d6..9394bc34e 100644
--- a/server/go/camlistored/ui/camli.js
+++ b/server/go/camlistored/ui/camli.js
@@ -63,7 +63,7 @@ function camliSigDiscovery(opts) {
     xhr.onreadystatechange = function() {
         if (xhr.readyState != 4) { return; }
         if (xhr.status != 200) {
-            opts.fail("no status 200; got " + xhr.status);
+            opts.fail("camliSigDiscovery expected status 200; got " + xhr.status);
             return;
         }
         sigdisco = JSON.parse(xhr.responseText);
@@ -171,6 +171,41 @@ function camliSign(clearObj, opts) {
         });
 }
 
+function camliUploadFileHelper(file, opts) {
+    opts = saneOpts(opts);
+    if (!disco.uploadHelper) {
+        opts.fail("no uploadHelper available");
+        return
+    }
+    var fd = new FormData();
+    fd.append(fd, file);
+    var xhr = new XMLHttpRequest();
+
+    xhr.open("POST", disco.uploadHelper);
+    xhr.onreadystatechange = function() {
+        if (xhr.readyState != 4) {
+             return;
+        }
+        if (xhr.status != 200) {
+            opts.fail("got status " + xhr.status);
+            return;
+        }
+        var resj;
+        try {
+            resj = JSON.parse(xhr.responseText);
+        } catch (x) {
+            opts.fail("error parsing JSON in upload response: " + xhr.responseText);
+            return;
+        }
+        if (resj.error) {
+            opts.fail("error uploading " + blobref + ": " + resj.error);
+            return;
+        }
+        opts.success(resj);
+    };
+    xhr.send(fd);
+}
+
 function camliUploadString(s, opts) {
     opts = saneOpts(opts);
     var blobref = "sha1-" + Crypto.SHA1(s);
@@ -205,7 +240,7 @@ function camliUploadString(s, opts) {
             opts.fail("error parsing JSON in upload response: " + xhr.responseText);
             return;
         }
-        if (resj.errorText) {
+        if (resj.errorText) {  // TODO: change this to error, not errorText, to be consistent
             opts.fail("error uploading " + blobref + ": " + resj.errorText);
             return;
         }
@@ -257,14 +292,14 @@ function camliGetRecentlyUpdatedPermanodes(opts) {
     xhr.onreadystatechange = function() {
         if (xhr.readyState != 4) { return; }
         if (xhr.status != 200) {
-            opts.fail("no status 200; got " + xhr.status);
+            opts.fail("camliGetRecentlyUpdatedPermanodes expected status 200; got " + xhr.status);
             return;
         }
         var resj;
         try {
             resj = JSON.parse(xhr.responseText);
         } catch(x) {
-            opts.fail("error parsing JSON in upload response: " + xhr.responseText);
+            opts.fail("error parsing JSON in response: " + xhr.responseText);
             return
         }
         opts.success(resj);
@@ -273,6 +308,33 @@ function camliGetRecentlyUpdatedPermanodes(opts) {
     xhr.send();
 }
 
+function camliFindExistingFileSchemas(bytesRef, opts) {
+    opts = saneOpts(opts);
+    var xhr = new XMLHttpRequest();
+    xhr.onreadystatechange = function() {
+        if (xhr.readyState != 4) { return; }
+        if (xhr.status != 200) {            
+            opts.fail("camliFindExistingFileSchemas expected status 200; got " + xhr.status + ", " + xhr.statusText);
+            return;
+        }
+        var resj;
+        try {
+            resj = JSON.parse(xhr.responseText);
+        } catch(x) {
+            opts.fail("error parsing JSON in response: " + xhr.responseText);
+            return
+        }
+        if (resj.error) {
+            opts.fail(resj.error);
+        } else {
+            opts.success(resj);
+        }
+    };
+    var path = disco.searchRoot + "camli/search/files?bytesref=" + bytesRef;
+    xhr.open("GET", path, true);
+    xhr.send();
+}
+
 // Returns true if the passed-in string might be a blobref.
 function isPlausibleBlobRef(blobRef) {
     return /^\w+-[a-f0-9]+$/.test(blobRef);
diff --git a/server/go/camlistored/ui/permanode.html b/server/go/camlistored/ui/permanode.html
index e7062585e..5af1c1055 100644
--- a/server/go/camlistored/ui/permanode.html
+++ b/server/go/camlistored/ui/permanode.html
@@ -7,6 +7,13 @@
   <script type="text/javascript" src="camli.js"></script>
   <script type="text/javascript" src="?camli.mode=config&cb=onConfiguration"></script>
   <script type="text/javascript" src="permanode.js"></script>
+<style>
+div.fileupload {
+    margin: 0.25em;
+    border: 1px solid #888;
+    padding: 0.25em;
+}
+</style>
 </head>
 <body>
   <div>[<a href="./">Home</a>]</div>
diff --git a/server/go/camlistored/ui/permanode.js b/server/go/camlistored/ui/permanode.js
index 7173bd1b2..a784b9f4e 100644
--- a/server/go/camlistored/ui/permanode.js
+++ b/server/go/camlistored/ui/permanode.js
@@ -130,28 +130,55 @@ var lastFiles;
 function handleFiles(files) {
     lastFiles = files;
 
-    info = document.getElementById("info");
-    t = "N files: " + files.length + "\n";
     for (var i = 0; i < files.length; i++) {
         var file = files[i];
-        t += "file[" + i + "] name=" + file.name + "; size=" + file.size + "; file.type=" + file.type + "\n";
-
-        (function(file) {
-             var fr = new FileReader();
-             fr.onload = function() {
-                 dataurl = fr.result;
-                 comma = dataurl.indexOf(",")
-                 if (comma != -1) {
-                     b64 = dataurl.substring(comma + 1);
-                     var arrayBuffer = Base64.decode(b64).buffer;
-                     var hash = Crypto.SHA1(new Uint8Array(arrayBuffer, 0));
-                     info.innerHTML += "File " + file.name + " = sha1-" + hash + "\n";                
-                 }
-             };
-             fr.readAsDataURL(file);
-        })(file);
+        startFileUpload(file);
     }
-    info.innerHTML += t;
+}
+
+function startFileUpload(file) {
+    var dnd = document.getElementById("dnd");
+    var up = document.createElement("div");
+    up.setAttribute("class", "fileupload");
+    dnd.appendChild(up);
+    var info = "name=" + file.name + " size=" + file.size + "; type=" + file.type;
+    up.innerHTML = info + " (scanning)";
+    var contentsRef; // set later
+
+    var onFail = function(msg) {
+        up.innerHTML = info + " <b>fail:</b> ";
+        up.appendChild(document.createTextNode(msg));
+    };
+
+    var onUploaded = function(res) {
+      alert("Uploaded: " + JSON.stringify(res, null, 2));
+    };
+        
+    var onFileSearch = function(res) {
+        if (res.files.length > 0) {
+            up.innerHTML = info + " <b>TODO: server dup, handle</b>";
+            alert("TODO: server already has it, maybe. verify the files in " + JSON.stringify(res, null, 2));
+            return;
+        } 
+        up.innerHTML = info + " <b>Uploading...</b>";
+        camliUploadFileHelper(file, { success: onUploaded, fail: onFail });
+    };
+
+    var fr = new FileReader();
+    fr.onload = function() {
+        dataurl = fr.result;
+        comma = dataurl.indexOf(",")
+        if (comma != -1) {
+            b64 = dataurl.substring(comma + 1);
+            var arrayBuffer = Base64.decode(b64).buffer;
+            var hash = Crypto.SHA1(new Uint8Array(arrayBuffer, 0));
+
+            contentsRef = "sha1-" + hash;
+            up.innerHTML = info + " (checking for dup of " + contentsRef + ")";
+            camliFindExistingFileSchemas(contentsRef, { success: onFileSearch, fail: onFail });
+        }
+    };
+    fr.readAsDataURL(file);
 }
 
 function onFileFormSubmit(e) {
diff --git a/server/go/camlistored/uploadhelper.go b/server/go/camlistored/uploadhelper.go
new file mode 100644
index 000000000..9fa4147ee
--- /dev/null
+++ b/server/go/camlistored/uploadhelper.go
@@ -0,0 +1,80 @@
+/*
+Copyright 2011 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"http"
+	"os"
+
+	"camli/httputil"
+	"camli/schema"
+)
+
+func (ui *UIHandler) serveUploadHelper(rw http.ResponseWriter, req *http.Request) {
+	rollSum := req.URL.Query().Get("rollsum") == "1"
+
+	ret := make(map[string]interface{})
+	defer httputil.ReturnJson(rw, ret)
+
+	if ui.Storage == nil {
+		ret["error"] = "No BlobRoot configured"
+		ret["errorType"] = "server"
+		return
+	}
+
+	mr, err := req.MultipartReader()
+	if err != nil {
+		ret["error"] = "reading body: " + err.String()
+                ret["errorType"] = "server"
+		return
+	}
+
+	got := make([]map[string]interface{}, 0)
+	for {
+		part, err := mr.NextPart()
+		if err == os.EOF {
+			break
+		}
+		if err != nil {
+			ret["error"] = "reading body: " + err.String()
+			ret["errorType"] = "server"
+			break
+		}
+		fileName := part.FileName()
+		if fileName == "" {
+			continue
+		}
+		writeFn := schema.WriteFileFromReader
+		if rollSum {
+			writeFn = schema.WriteFileFromReaderRolling
+		}
+		br, err := writeFn(ui.Storage, fileName, part)
+
+		if err == nil {
+			got = append(got, map[string]interface{}{
+				"filename": part.FileName(),
+				"formname": part.FormName(),
+				"fileref": br.String(),
+			})
+		} else {
+			ret["error"] = "writing to blobserver: " + err.String()
+			return
+		}
+	}
+	ret["got"] = got
+}
+