diff --git a/analyzer/protobuf.spicy b/analyzer/protobuf.spicy
index bcaef43..925da84 100644
--- a/analyzer/protobuf.spicy
+++ b/analyzer/protobuf.spicy
@@ -2,25 +2,75 @@ module protobuf;
 
 import zeek;
 
-# TODO: Our example here models a simple example packet format of static size:
-# 19 payload bytes, followed by the protocol number for the next layer, for
-# which the data then follows subsequently. (This is just what our test trace
-# happens to contain). Adapt as suitable.
 public type Packet = unit {
-    payload: bytes &size=19;
-    protocol: uint16; # next-layer protocol, values need to be mapped to analyzers in Zeek scriptland
+    payload: Message;
 
     on %done {
         # Feed into Zeek's next-layer packet analysis.
-        zeek::forward_packet(self.protocol);
+        zeek::forward_packet(self.payload);
     }
 };
 
-type WireType = enum {
-    VARINT = 0x00,
-    I64    = 0x01,
-    LEN    = 0x02,
-    SGROUP = 0x03, # deprecated
-    EGROUP = 0x04, # deprecated
-    I32    = 0x05
+# TODO:
+# message    := (tag value)*
+type Message = unit {
+};
+
+# TODO:
+# tag        := (field << 3) bit-or wire_type;
+#                 encoded as uint32 varint
+type Tag = unit {
+};
+
+# TODO:
+# value      := varint      for wire_type == VARINT,
+#               i32         for wire_type == I32,
+#               i64         for wire_type == I64,
+#               len-prefix  for wire_type == LEN,
+#               <empty>     for wire_type == SGROUP or EGROUP
+type Value = unit {
+};
+
+# TODO:
+# varint     := int32 | int64 | uint32 | uint64 | bool | enum | sint32 | sint64;
+#                 encoded as varints (sintN are ZigZag-encoded first)
+type VarInt = unit {
+};
+
+# TODO:
+# i32        := sfixed32 | fixed32 | float;
+#                 encoded as 4-byte little-endian;
+#                 memcpy of the equivalent C types (u?int32_t, float)
+type I32 = unit {
+};
+
+# TODO:
+# i64        := sfixed64 | fixed64 | double;
+#                 encoded as 8-byte little-endian;
+#                 memcpy of the equivalent C types (u?int64_t, double)
+type I64 = unit {
+};
+
+# TODO:
+# len-prefix := size (message | string | bytes | packed);
+#                 size encoded as int32 varint
+type LenPrefix = unit {
+};
+
+# TODO:
+# string     := valid UTF-8 string (e.g. ASCII);
+#                 max 2GB of bytes
+type String = unit {
+};
+
+# TODO:
+# bytes      := any sequence of 8-bit bytes;
+#                 max 2GB of bytes
+type Bytes = unit {
+};
+
+# TODO:
+# packed     := varint* | i32* | i64*,
+#                 consecutive values of the type specified in `.proto`
+type Packed = unit {
 };