diff --git a/packet.go b/packet.go
new file mode 100644
index 0000000..d60d7f4
--- /dev/null
+++ b/packet.go
@@ -0,0 +1,34 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/golang/protobuf/proto"
+)
+
+// packet represents the top-level envelope in the dota replay format. All
+// data in the replay file is packed into packets of at most 65kb.
+type packet struct {
+	cmd  packetType
+	tick int64
+	body []byte
+}
+
+func (p packet) String() string {
+	if len(p.body) > 30 {
+		return fmt.Sprintf("{packet cmd: %v tick: %v size: %d body: %x...}", p.cmd, p.tick, len(p.body), p.body[:27])
+	}
+	return fmt.Sprintf("{packet cmd: %v tick: %v size: %d body: %x}", p.cmd, p.tick, len(p.body), p.body)
+}
+
+func (p *packet) Open(m *messageFactory, pbuf *proto.Buffer) (proto.Message, error) {
+	msg, err := m.BuildPacket(p.cmd)
+	if err != nil {
+		return nil, err
+	}
+	pbuf.SetBuf(p.body)
+	if err := pbuf.Unmarshal(msg); err != nil {
+		return nil, err
+	}
+	return msg, nil
+}