diff -r 000000000000 -r 6474c204b198 mobile/android/base/sync/net/SyncStorageResponse.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/sync/net/SyncStorageResponse.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,72 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.sync.net;
+
+import java.io.IOException;
+import java.util.HashMap;
+
+import org.mozilla.gecko.background.common.log.Logger;
+
+import ch.boye.httpclientandroidlib.HttpResponse;
+
+public class SyncStorageResponse extends SyncResponse {
+
+  // Responses that are actionable get constant status codes.
+  public static final String RESPONSE_CLIENT_UPGRADE_REQUIRED = "16";
+
+  private static final String LOG_TAG = "SyncStorageResponse";
+  public static HashMap<String, String> SERVER_ERROR_MESSAGES;
+  static {
+    HashMap<String, String> errors = new HashMap<String, String>();
+
+    // Sync protocol errors.
+    errors.put("1", "Illegal method/protocol");
+    errors.put("2", "Incorrect/missing CAPTCHA");
+    errors.put("3", "Invalid/missing username");
+    errors.put("4", "Attempt to overwrite data that can't be overwritten (such as creating a user ID that already exists)");
+    errors.put("5", "User ID does not match account in path");
+    errors.put("6", "JSON parse failure");
+    errors.put("7", "Missing password field");
+    errors.put("8", "Invalid Weave Basic Object");
+    errors.put("9", "Requested password not strong enough");
+    errors.put("10", "Invalid/missing password reset code");
+    errors.put("11", "Unsupported function");
+    errors.put("12", "No email address on file");
+    errors.put("13", "Invalid collection");
+    errors.put("14", "User over quota");
+    errors.put("15", "The email does not match the username");
+    errors.put(RESPONSE_CLIENT_UPGRADE_REQUIRED, "Client upgrade required");
+    errors.put("255", "An unexpected server error occurred: pool is empty.");
+
+    // Infrastructure-generated errors.
+    errors.put("\"server issue: getVS failed\"",                         "server issue: getVS failed");
+    errors.put("\"server issue: prefix not set\"",                       "server issue: prefix not set");
+    errors.put("\"server issue: host header not received from client\"", "server issue: host header not received from client");
+    errors.put("\"server issue: database lookup failed\"",               "server issue: database lookup failed");
+    errors.put("\"server issue: database is not healthy\"",              "server issue: database is not healthy");
+    errors.put("\"server issue: database not in pool\"",                 "server issue: database not in pool");
+    errors.put("\"server issue: database marked as down\"",              "server issue: database marked as down");
+    SERVER_ERROR_MESSAGES = errors;
+  }
+  public static String getServerErrorMessage(String body) {
+    Logger.debug(LOG_TAG, "Looking up message for body \"" + body + "\"");
+    if (SERVER_ERROR_MESSAGES.containsKey(body)) {
+      return SERVER_ERROR_MESSAGES.get(body);
+    }
+    return body;
+  }
+
+
+  public SyncStorageResponse(HttpResponse res) {
+    this.response = res;
+  }
+
+  public String getErrorMessage() throws IllegalStateException, IOException {
+    return SyncStorageResponse.getServerErrorMessage(this.body().trim());
+  }
+
+  // TODO: Content-Type and Content-Length validation.
+
+}