diff --git a/storage/notifications/event.go b/storage/notifications/event.go
new file mode 100644
index 000000000..3c000dc20
--- /dev/null
+++ b/storage/notifications/event.go
@@ -0,0 +1,122 @@
+package notifications
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/docker/distribution/digest"
+)
+
+// EventAction constants used in action field of Event.
+const (
+	EventActionPull   = "pull"
+	EventActionPush   = "push"
+	EventActionDelete = "delete"
+	EventActionPing   = "ping"
+)
+
+// EventsMediaType is the mediatype for the json event envelope. If the Event,
+// ActorRecord, SourceRecord or Envelope structs change, the version number
+// should be incremented.
+const EventsMediaType = "application/vnd.docker.distribution.events.v1+json"
+
+// Envelope defines the fields of a json event envelope message that can hold
+// one or more events.
+type Envelope struct {
+	// Events make up the contents of the envelope. Events present in a single
+	// envelope are not necessarily related.
+	Events []Event `json:"events,omitempty"`
+}
+
+// TODO(stevvooe): The event type should be separate from the json format. It
+// should be defined as an interface. Leaving as is for now since we don't
+// need that at this time. If we make this change, the struct below would be
+// called "EventRecord".
+
+// Event provides the fields required to describe a registry event.
+type Event struct {
+	// ID provides a unique identifier for the event.
+	ID string `json:"uuid,omitempty"`
+
+	// Timestamp is the time at which the event occurred.
+	Timestamp time.Time `json:"timestamp,omitempty"`
+
+	// Action indicates what action encompasses the provided event.
+	Action string `json:"action,omitempty"`
+
+	// Target uniquely describes the target of the event.
+	Target struct {
+		// Type should be "manifest" or "blob"
+		Type string `json:"type,omitempty"`
+
+		// Name identifies the named repository.
+		Name string `json:"name,omitempty"`
+
+		// Digest should identify the object in the repository.
+		Digest digest.Digest `json:"digest,omitempty"`
+
+		// Tag is present if the operation involved a tagged manifest.
+		Tag string `json:"tag,omitempty"`
+
+		// URL provides a link to the content on the relevant repository instance.
+		URL string `json:"url,omitempty"`
+	} `json:"target,omitempty"`
+
+	// Actor specifies the agent that initiated the event. For most
+	// situations, this could be from the authorizaton context of the request.
+	Actor ActorRecord `json:"actor,omitempty"`
+
+	// Source identifies the registry node that generated the event. Put
+	// differently, while the actor "initiates" the event, the source
+	// "generates" it.
+	Source SourceRecord `json:"source,omitempty"`
+}
+
+// ActorRecord specifies the agent that initiated the event. For most
+// situations, this could be from the authorizaton context of the request.
+type ActorRecord struct {
+	// Name corresponds to the subject or username associated with the
+	// request context that generated the event.
+	Name string `json:"name,omitempty"`
+
+	// Addr contains the ip or hostname and possibly port of the client
+	// connection that initiated the event.
+	Addr string `json:"addr,omitempty"`
+}
+
+// SourceRecord identifies the registry node that generated the event. Put
+// differently, while the actor "initiates" the event, the source "generates"
+// it.
+type SourceRecord struct {
+	// Addr contains the ip or hostname and the port of the registry node
+	// that generated the event. Generally, this will be resolved by
+	// os.Hostname() along with the running port.
+	Addr string `json:"addr,omitempty"`
+
+	// Host is the dns name of the registry cluster, as configured.
+	Host string `json:"host,omitempty"`
+
+	// RequestID uniquely identifies the registry request that generated the
+	// event.
+	RequestID string `json:"request_id,omitempty"`
+}
+
+var (
+	// ErrSinkClosed is returned if a write is issued to a sink that has been
+	// closed. If encountered, the error should be considered terminal and
+	// retries will not be successful.
+	ErrSinkClosed = fmt.Errorf("sink: closed")
+)
+
+// Sink accepts and sends events.
+type Sink interface {
+	// Write writes one or more events to the sink. If no error is returned,
+	// the caller will assume that all events have been committed and will not
+	// try to send them again. If an error is received, the caller may retry
+	// sending the event. The caller should cede the slice of memory to the
+	// sink and not modify it after calling this method.
+	Write(events ...Event) error
+
+	// Close the sink, possibly waiting for pending events to flush.
+	Close() error
+}
diff --git a/storage/notifications/event_test.go b/storage/notifications/event_test.go
new file mode 100644
index 000000000..37e43c66b
--- /dev/null
+++ b/storage/notifications/event_test.go
@@ -0,0 +1,131 @@
+package notifications
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+	"time"
+)
+
+// TestEventJSONFormat provides silly test to detect if the event format or
+// envelope has changed. If this code fails, the revision of the protocol may
+// need to be incremented.
+func TestEventEnvelopeJSONFormat(t *testing.T) {
+	var expected = strings.TrimSpace(`
+{
+   "events": [
+      {
+         "uuid": "asdf-asdf-asdf-asdf-0",
+         "timestamp": "2006-01-02T15:04:05Z",
+         "action": "push",
+         "target": {
+            "type": "manifest",
+            "name": "library/test",
+            "digest": "sha256:0123456789abcdef0",
+            "tag": "latest",
+            "url": "http://example.com/v2/library/test/manifests/latest"
+         },
+         "actor": {
+            "name": "test-actor",
+            "addr": "hostname.local"
+         },
+         "source": {
+            "addr": "hostname.local",
+            "host": "registrycluster.local",
+            "request_id": "asdfasdf"
+         }
+      },
+      {
+         "uuid": "asdf-asdf-asdf-asdf-1",
+         "timestamp": "2006-01-02T15:04:05Z",
+         "action": "push",
+         "target": {
+            "type": "blob",
+            "name": "library/test",
+            "digest": "tarsum.v2+sha256:0123456789abcdef1",
+            "url": "http://example.com/v2/library/test/manifests/latest"
+         },
+         "actor": {
+            "name": "test-actor",
+            "addr": "hostname.local"
+         },
+         "source": {
+            "addr": "hostname.local",
+            "host": "registrycluster.local",
+            "request_id": "asdfasdf"
+         }
+      },
+      {
+         "uuid": "asdf-asdf-asdf-asdf-2",
+         "timestamp": "2006-01-02T15:04:05Z",
+         "action": "push",
+         "target": {
+            "type": "blob",
+            "name": "library/test",
+            "digest": "tarsum.v2+sha256:0123456789abcdef2",
+            "url": "http://example.com/v2/library/test/manifests/latest"
+         },
+         "actor": {
+            "name": "test-actor",
+            "addr": "hostname.local"
+         },
+         "source": {
+            "addr": "hostname.local",
+            "host": "registrycluster.local",
+            "request_id": "asdfasdf"
+         }
+      }
+   ]
+}
+	`)
+
+	tm, err := time.Parse(time.RFC3339, time.RFC3339[:len(time.RFC3339)-5])
+	if err != nil {
+		t.Fatalf("error creating time: %v", err)
+	}
+
+	var prototype Event
+	prototype.Action = "push"
+	prototype.Timestamp = tm
+	prototype.Actor.Addr = "hostname.local"
+	prototype.Actor.Name = "test-actor"
+	prototype.Source.Addr = "hostname.local"
+	prototype.Source.Host = "registrycluster.local"
+	prototype.Source.RequestID = "asdfasdf"
+
+	var manifestPush Event
+	manifestPush = prototype
+	manifestPush.ID = "asdf-asdf-asdf-asdf-0"
+	manifestPush.Target.Digest = "sha256:0123456789abcdef0"
+	manifestPush.Target.Type = "manifest"
+	manifestPush.Target.Name = "library/test"
+	manifestPush.Target.Tag = "latest"
+	manifestPush.Target.URL = "http://example.com/v2/library/test/manifests/latest"
+
+	var layerPush0 Event
+	layerPush0 = prototype
+	layerPush0.ID = "asdf-asdf-asdf-asdf-1"
+	layerPush0.Target.Digest = "tarsum.v2+sha256:0123456789abcdef1"
+	layerPush0.Target.Type = "blob"
+	layerPush0.Target.Name = "library/test"
+	layerPush0.Target.URL = "http://example.com/v2/library/test/manifests/latest"
+
+	var layerPush1 Event
+	layerPush1 = prototype
+	layerPush1.ID = "asdf-asdf-asdf-asdf-2"
+	layerPush1.Target.Digest = "tarsum.v2+sha256:0123456789abcdef2"
+	layerPush1.Target.Type = "blob"
+	layerPush1.Target.Name = "library/test"
+	layerPush1.Target.URL = "http://example.com/v2/library/test/manifests/latest"
+
+	var envelope Envelope
+	envelope.Events = append(envelope.Events, manifestPush, layerPush0, layerPush1)
+
+	p, err := json.MarshalIndent(envelope, "", "   ")
+	if err != nil {
+		t.Fatalf("unexpected error marshaling envelope: %v", err)
+	}
+	if string(p) != expected {
+		t.Fatalf("format has changed\n%s\n != \n%s", string(p), expected)
+	}
+}