diff --git a/tools/patman/commit.py b/tools/patman/commit.py
new file mode 100644
index 0000000..7144e54
--- /dev/null
+++ b/tools/patman/commit.py
@@ -0,0 +1,87 @@
+# Copyright (c) 2011 The Chromium OS Authors.
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+import re
+
+# Separates a tag: at the beginning of the subject from the rest of it
+re_subject_tag = re.compile('([^:]*):\s*(.*)')
+
+class Commit:
+    """Holds information about a single commit/patch in the series.
+
+    Args:
+        hash: Commit hash (as a string)
+
+    Variables:
+        hash: Commit hash
+        subject: Subject line
+        tags: List of maintainer tag strings
+        changes: Dict containing a list of changes (single line strings).
+            The dict is indexed by change version (an integer)
+        cc_list: List of people to aliases/emails to cc on this commit
+    """
+    def __init__(self, hash):
+        self.hash = hash
+        self.subject = None
+        self.tags = []
+        self.changes = {}
+        self.cc_list = []
+
+    def AddChange(self, version, info):
+        """Add a new change line to the change list for a version.
+
+        Args:
+            version: Patch set version (integer: 1, 2, 3)
+            info: Description of change in this version
+        """
+        if not self.changes.get(version):
+            self.changes[version] = []
+        self.changes[version].append(info)
+
+    def CheckTags(self):
+        """Create a list of subject tags in the commit
+
+        Subject tags look like this:
+
+            propounder: Change the widget to propound correctly
+
+        Multiple tags are supported. The list is updated in self.tag
+
+        Returns:
+            None if ok, else the name of a tag with no email alias
+        """
+        str = self.subject
+        m = True
+        while m:
+            m = re_subject_tag.match(str)
+            if m:
+                tag = m.group(1)
+                self.tags.append(tag)
+                str = m.group(2)
+        return None
+
+    def AddCc(self, cc_list):
+        """Add a list of people to Cc when we send this patch.
+
+        Args:
+            cc_list:    List of aliases or email addresses
+        """
+        self.cc_list += cc_list