diff --git a/testing/mozharness/README.txt b/testing/mozharness/README.txt
new file mode 100644
index 000000000000..a4b534a419d3
--- /dev/null
+++ b/testing/mozharness/README.txt
@@ -0,0 +1,2 @@
+mozharness.json is a manifest file that is currently only used on try.
+It allows you to lock mozharness to a repository and a revision.
diff --git a/testing/mozharness/mozharness.json b/testing/mozharness/mozharness.json
new file mode 100644
index 000000000000..0908d77c9e3e
--- /dev/null
+++ b/testing/mozharness/mozharness.json
@@ -0,0 +1,4 @@
+{
+    "repo": "http://hg.mozilla.org/build/mozharness",
+    "revision": "production"
+}
diff --git a/testing/mozharness/repository_from_code.py b/testing/mozharness/repository_from_code.py
new file mode 100644
index 000000000000..addfe69fd29a
--- /dev/null
+++ b/testing/mozharness/repository_from_code.py
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+#! /usr/bin/env python
+# 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/.
+
+#
+# Script name:   repository_manifest.py
+# Purpose:       Reads from a json file a repository and revision to use.
+#                If none is found we fall back to the default values.
+# Author(s):     Zambrano Gasparnian, Armen <armenzg@mozilla.com>
+# Target:        Python 2.7.x
+#
+from optparse import OptionParser
+import json
+import re
+import urllib2
+import urlparse
+import sys
+import os
+
+def main():
+    '''
+    Determine which repository and revision mozharness.json indicates.
+    If none is found we fall back to the default repository
+    '''
+    parser = OptionParser()
+    parser.add_option("--repository-manifest-url", dest="repository_manifest_url", type="string",
+                      help="It indicates from where to download the talos.json file.")
+    (options, args) = parser.parse_args()
+
+    # 1) check that the url was passed
+    if options.repository_manifest_url == None:
+        print "You need to specify --repository-manifest-url."
+        sys.exit(1)
+
+    # 2) try to download the talos.json file
+    try:
+        jsonFilename = download_file(options.talos_json_url)
+    except Exception, e:
+        print "ERROR: We tried to download the talos.json file but something failed."
+        print "ERROR: %s" % str(e)
+        sys.exit(1)
+
+    # 3) download the necessary files
+    print "INFO: talos.json URL: %s" % options.talos_json_url
+    try:
+        key = 'talos.zip'
+        entity = get_value(jsonFilename, key)
+        if passesRestrictions(options.talos_json_url, entity["url"]):
+            # the key is at the same time the filename e.g. talos.zip
+            print "INFO: Downloading %s as %s" % (entity["url"], os.path.join(entity["path"], key))
+            download_file(entity["url"], entity["path"], key)
+        else:
+            print "ERROR: You have tried to download a file " + \
+                  "from: %s " % entity["url"] + \
+                  "which is a location different than http://talos-bundles.pvt.build.mozilla.org/"
+            print "ERROR: This is only allowed for the certain branches."
+            sys.exit(1)
+    except Exception, e:
+        print "ERROR: %s" % str(e)
+        sys.exit(1)
+
+def passesRestrictions(talosJsonUrl, fileUrl):
+    '''
+    Only certain branches are exempted from having to host their downloadable files
+    in talos-bundles.pvt.build.mozilla.org
+    '''
+    if talosJsonUrl.startswith("http://hg.mozilla.org/try/") or \
+       talosJsonUrl.startswith("https://hg.mozilla.org/try/") or \
+       talosJsonUrl.startswith("http://hg.mozilla.org/projects/pine/") or \
+       talosJsonUrl.startswith("https://hg.mozilla.org/projects/pine/") or \
+       talosJsonUrl.startswith("http://hg.mozilla.org/projects/ash/") or \
+       talosJsonUrl.startswith("https://hg.mozilla.org/projects/ash/"):
+        return True
+    else:
+        p = re.compile('^http://talos-bundles.pvt.build.mozilla.org/')
+        m = p.match(fileUrl)
+        if m == None:
+            return False
+        return True
+
+def get_filename_from_url(url):
+    '''
+    This returns the filename of the file we're trying to download
+    '''
+    parsed = urlparse.urlsplit(url.rstrip('/'))
+    if parsed.path != '':
+        return parsed.path.rsplit('/', 1)[-1]
+    else:
+        print "ERROR: We were trying to download a file from %s " + \
+              "but the URL seems to be incorrect."
+        sys.exit(1)
+
+def download_file(url, path="", saveAs=None):
+    '''
+    It downloads a file from URL to the indicated path
+    '''
+    req = urllib2.Request(url)
+    f = urllib2.urlopen(req)
+    if path != "" and not os.path.isdir(path):
+        try:
+            os.makedirs(path)
+            print "INFO: directory %s created" % path
+        except Exception, e:
+            print "ERROR: %s" % str(e)
+            sys.exit(1)
+    filename = saveAs if saveAs else get_filename_from_url(url)
+    local_file = open(os.path.join(path, filename), 'wb')
+    local_file.write(f.read())
+    local_file.close()
+    return filename
+
+def get_value(json_filename, key):
+    '''
+    It loads up a JSON file and returns the value for the given string
+    '''
+    f = open(json_filename, 'r')
+    return json.load(f)[key]
+
+if __name__ == '__main__':
+    main()