diff --git a/debian/control b/debian/control
index e35b8b0..f0dde19 100644
--- a/debian/control
+++ b/debian/control
@@ -1,27 +1,28 @@
 Source: swh-loader-git
 Maintainer: Software Heritage developers <swh-devel@inria.fr>
 Section: python
 Priority: optional
 Build-Depends: debhelper (>= 9),
                dh-python,
                python3-all,
                python3-nose,
                python3-dulwich,
                python3-retrying,
                python3-setuptools,
+               python3-click,
                python3-swh.core (>= 0.0.7~),
                python3-swh.model (>= 0.0.3~),
                python3-swh.scheduler,
                python3-swh.storage (>= 0.0.50~),
                python3-vcversioner
 Standards-Version: 3.9.6
 Homepage: https://forge.softwareheritage.org/diffusion/DLDG/
 
 Package: python3-swh.loader.git
 Architecture: all
 Depends: python3-swh.core (>= 0.0.7~),
          python3-swh.storage (>= 0.0.50~),
          python3-swh.model (>= 0.0.3~),
          ${misc:Depends},
          ${python3:Depends}
 Description: Software Heritage Git loader
diff --git a/requirements.txt b/requirements.txt
index ef55e34..e7b0a99 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,8 @@
 dulwich
 retrying
 vcversioner
+click
 swh.core >= 0.0.7
 swh.model >= 0.0.3
 swh.scheduler
 swh.storage >= 0.0.50
diff --git a/swh/loader/git/reader.py b/swh/loader/git/reader.py
new file mode 100644
index 0000000..69def1b
--- /dev/null
+++ b/swh/loader/git/reader.py
@@ -0,0 +1,95 @@
+# Copyright (C) 2016  The Software Heritage developers
+# See the AUTHORS file at the top-level directory of this distribution
+# License: GNU General Public License version 3, or any later version
+# See top-level LICENSE file for more information
+
+import click
+import datetime
+
+from collections import defaultdict
+
+from .updater import BulkUpdater
+from .loader import GitLoader
+
+
+class GitSha1Reader(GitLoader):
+    """Disk git sha1 reader. Only read and dump sha1s in stdout.
+
+    """
+    def fetch_data(self):
+        """Fetch the data from the data source"""
+        for oid in self.iter_objects():
+            type_name = self.repo[oid].type_name
+            if type_name != b'blob':
+                continue
+            yield oid
+
+    def load(self, *args, **kwargs):
+        self.prepare(*args, **kwargs)
+        try:
+            for oid in self.fetch_data():
+                yield oid.decode('utf-8')
+        except:
+            pass
+
+
+class GitSha1RemoteReader(BulkUpdater):
+    """Disk git sha1 reader to dump only repo's content sha1 list.
+
+    """
+    def list_pack(self, pack_data, pack_size):
+        """Override list_pack to only keep blobs data.
+
+        """
+        id_to_type = {}
+        type_to_ids = defaultdict(set)
+
+        inflater = self.get_inflater()
+
+        for obj in inflater:
+            type, id = obj.type_name, obj.id
+            if type != b'blob':
+                continue
+            id_to_type[id] = type
+            type_to_ids[type].add(id)
+
+        return id_to_type, type_to_ids
+
+    def load(self, *args, **kwargs):
+        self.prepare(*args, **kwargs)
+        origin = self.get_origin()
+        self.origin_id = self.send_origin(origin)
+
+        try:
+            self.fetch_data()
+            for oid in self.id_to_type.keys():
+                yield oid.decode('utf-8')
+        except:
+            pass
+
+
+@click.command()
+@click.option('--origin-url', help='Origin\'s url')
+@click.option('--source', help='origin\'s source url (disk or remote)')
+def main(origin_url, source):
+    import logging
+
+    logging.basicConfig(
+        level=logging.DEBUG,
+        format='%(asctime)s %(process)d %(message)s'
+    )
+
+    if source.startswith('/'):
+        loader = GitSha1Reader()
+        fetch_date = datetime.datetime.now(tz=datetime.timezone.utc)
+        r = loader.load(origin_url, source, fetch_date)
+    else:
+        loader = GitSha1RemoteReader()
+        r = loader.load(origin_url, source)
+
+    for id in r:
+        print(id)
+
+
+if __name__ == '__main__':
+    main()