diff --git a/setup.py b/setup.py
index 9b38f790b..d1b8f0680 100755
--- a/setup.py
+++ b/setup.py
@@ -41,6 +41,7 @@ setup(
         "pynacl",
         "daemonize",
         "py-bcrypt",
+        "frozendict>=0.4",
     ],
     dependency_links=[
         "https://github.com/matrix-org/syutil/tarball/v0.0.2#egg=syutil-0.0.2",
diff --git a/synapse/events/__init__.py b/synapse/events/__init__.py
new file mode 100644
index 000000000..eefc9d3b3
--- /dev/null
+++ b/synapse/events/__init__.py
@@ -0,0 +1,120 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014 OpenMarket Ltd
+#
+# 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.
+
+from frozendict import frozendict
+
+
+class _EventInternalMetadata(object):
+    def __init__(self, internal_metadata_dict):
+        self.__dict__ = internal_metadata_dict
+
+    def get_dict(self):
+        return dict(self.__dict__)
+
+
+class Event(object):
+    def __init__(self, event_dict, internal_metadata_dict={}):
+        self._signatures = event_dict.get("signatures", {})
+        self._unsigned = event_dict.get("unsigned", {})
+
+        self._original = {
+            k: v
+            for k, v in event_dict.items()
+            if k not in ["signatures", "unsigned"]
+        }
+
+        self._event_dict = frozendict(self._original)
+
+        self.internal_metadata = _EventInternalMetadata(
+            internal_metadata_dict
+        )
+
+    @property
+    def auth_events(self):
+        return self._event_dict["auth_events"]
+
+    @property
+    def content(self):
+        return self._event_dict["content"]
+
+    @property
+    def event_id(self):
+        return self._event_dict["event_id"]
+
+    @property
+    def hashes(self):
+        return self._event_dict["hashes"]
+
+    @property
+    def origin(self):
+        return self._event_dict["origin"]
+
+    @property
+    def prev_events(self):
+        return self._event_dict["prev_events"]
+
+    @property
+    def prev_state(self):
+        return self._event_dict["prev_state"]
+
+    @property
+    def room_id(self):
+        return self._event_dict["room_id"]
+
+    @property
+    def signatures(self):
+        return self._signatures
+
+    @property
+    def state_key(self):
+        return self._event_dict["state_key"]
+
+    @property
+    def type(self):
+        return self._event_dict["type"]
+
+    @property
+    def unsigned(self):
+        return self._unsigned
+
+    @property
+    def user_id(self):
+        return self._event_dict["sender"]
+
+    @property
+    def sender(self):
+        return self._event_dict["sender"]
+
+    def get_dict(self):
+        d = dict(self._original)
+        d.update({
+            "signatures": self._signatures,
+            "unsigned": self._unsigned,
+        })
+
+        return d
+
+    def get_internal_metadata_dict(self):
+        return self.internal_metadata.get_dict()
+
+    def get_pdu_json(self, time_now=None):
+        pdu_json = self.get_dict()
+
+        if time_now is not None and "age_ts" in pdu_json["unsigned"]:
+            age = time_now - pdu_json["unsigned"]["age_ts"]
+            pdu_json.setdefault("unsigned", {})["age"] = int(age)
+            del pdu_json["unsigned"]["age_ts"]
+
+        return pdu_json
\ No newline at end of file
diff --git a/synapse/events/builder.py b/synapse/events/builder.py
new file mode 100644
index 000000000..d741795bc
--- /dev/null
+++ b/synapse/events/builder.py
@@ -0,0 +1,74 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014 OpenMarket Ltd
+#
+# 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.
+
+from . import Event
+
+from synapse.types import EventID
+
+from synapse.util.stringutils import random_string
+
+
+class EventBuilder(object):
+    def __init__(self, key_values={}):
+        self._event_dict = dict(key_values)
+        self._metadata = {}
+
+    def update_event_key(self, key, value):
+        self._event_dict[key] = value
+
+    def update_event_keys(self, other_dict):
+        self._event_dict.update(other_dict)
+
+    def update_internal_key(self, key, value):
+        self._metadata[key] = value
+
+    def build(self):
+        return Event(
+            self._event_dict,
+            self._metadata,
+        )
+
+
+class EventBuilderFactory(object):
+    def __init__(self, clock, hostname):
+        self.clock = clock
+        self.hostname = hostname
+
+        self.event_id_count = 0
+
+    def create_event_id(self):
+        i = str(self.event_id_count)
+        self.event_id_count += 1
+
+        local_part = str(int(self.clock.time())) + i + random_string(5)
+
+        e_id = EventID.create(local_part, self.hostname)
+
+        return e_id.to_string()
+
+    def new(self, key_values={}):
+        if "event_id" not in key_values:
+            key_values["event_id"] = self.create_event_id()
+
+        time_now = self.clock.time_msec()
+
+        key_values.setdefault("origin", self.hostname)
+        key_values.setdefault("origin_server_ts", time_now)
+
+        if "unsigned" in key_values:
+            age = key_values["unsigned"].pop("age", 0)
+            key_values["unsigned"].setdefault("age_ts", time_now - age)
+
+        return EventBuilder(key_values=key_values,)
\ No newline at end of file