diff --git a/src/client/chunk.zig b/src/client/chunk.zig
new file mode 100644
index 0000000..3a8de97
--- /dev/null
+++ b/src/client/chunk.zig
@@ -0,0 +1,73 @@
+const std = @import("std");
+
+const shared = @import("shared");
+const enet   = @import("c.zig").enet;
+
+pub fn spawn(self: *shared.chunk.Chunk, allocator: std.mem.Allocator, comptime T: type, value: T) !shared.entity.id {
+    std.debug.assert(value.id != shared.entity.INVALID_ID);
+
+    const ptr = try allocator.create(T);
+    errdefer allocator.destroy(ptr);
+
+    ptr.* = value;
+
+    const ref = shared.entity.makeRef(T, ptr);
+
+    try self.entities.append(allocator, ref);
+
+    return ptr.id;
+}
+
+pub fn find(self: *shared.chunk.Chunk, id: shared.entity.id) ?shared.entity.Ref {
+    for (self.entities.items) |ref| {
+        switch (ref) {
+            inline else => |ptr| {
+                if (ptr.id == id) {
+                    return ref;
+                }
+            }
+        }
+    }
+
+    return null;
+}
+
+pub fn findT(self: *shared.chunk.Chunk, comptime T: type, id: shared.entity.id) ?*T {
+    for (self.entities.items) |ref| {
+        switch (ref) {
+            inline else => |ptr| {
+                if (ptr.id == id and @TypeOf(ptr) == *T) {
+                    return ptr;
+                }
+            }
+        }
+    }
+
+    return null;
+}
+
+pub fn despawn(self: *shared.chunk.Chunk, allocator: std.mem.Allocator, id: shared.entity.id) bool {
+    var i: usize = 0;
+    while (i < self.entities.items.len) {
+        const ref = self.entities.items[i];
+
+        var found = false;
+
+        switch (ref) {
+            inline else => |ptr| {
+                if (ptr.id == id) {
+                    allocator.destroy(ptr);
+                    found = true;
+                }
+            },
+        }
+
+        if (found) {
+            _ = self.entities.swapRemove(i);
+            return true;
+        }
+
+        i += 1;
+    }
+    return false;
+}
diff --git a/src/shared/protocol_v1.zig b/src/shared/protocol_v1.zig
new file mode 100644
index 0000000..4bf062b
--- /dev/null
+++ b/src/shared/protocol_v1.zig
@@ -0,0 +1,158 @@
+const std    = @import("std");
+const zm     = @import("zmath");
+// const bufzilla = @import("bufzilla");
+
+const entity = @import("entity.zig");
+const bits   = @import("bits.zig");
+
+pub const SERVER_PORT: u16 = 1337;
+
+const MessageKind = enum(c_char) {
+    spawn_entity,
+    update_entity,
+    despawn_entity,
+};
+
+pub const Message = union(MessageKind) {
+    spawn_entity: SpawnEntity,
+    update_entity: UpdateEntity,
+    despawn_entity: DespawnEntity,
+};
+
+const EntityKind = enum(c_char) {
+    soldier,
+    alien,
+};
+
+pub const SpawnEntity = union(EntityKind) {
+    soldier: Soldier,
+    alien: Alien,
+};
+
+pub const UpdateEntity = union(EntityKind) {
+    soldier: Soldier,
+    alien: Alien,
+};
+
+pub const DespawnEntity = union(EntityKind) {
+    soldier: Soldier,
+    alien: Alien,
+};
+
+pub fn makeSpawnMessage(e: entity.Ref) Message {
+    switch (e) {
+        .Soldier => |s| { return Soldier.makeSpawn(s.*); },
+        .Alien   => |a| { return Alien.makeSpawn(a.*); },
+    }
+}
+
+pub fn makeUpdateMessage(e: entity.Ref) Message {
+    switch (e) {
+        .Soldier => |s| { return Soldier.makeUpdate(s.*); },
+        .Alien   => |a| { return Alien.makeUpdate(a.*); },
+    }
+}
+
+pub fn makeDespawnMessage(e: entity.Ref) Message {
+    switch (e) {
+        .Soldier => |s| { return Soldier.makeDespawn(s.*); },
+        .Alien   => |a| { return Alien.makeDespawn(a.*); },
+    }
+}
+
+pub const Soldier = struct {
+    id: entity.id = entity.INVALID_ID,
+    hp: i32,
+    pos: zm.Vec,
+    vel: zm.Vec,
+
+    pub fn init(soldier: entity.Soldier) Soldier {
+        return .{
+            .id = soldier.id,
+            .hp = soldier.hp,
+            .pos = soldier.pos,
+            .vel = soldier.vel,
+        };
+    }
+
+    pub fn makeSpawn(soldier: entity.Soldier) Message {
+        return .{
+            .spawn_entity = .{ .soldier = init(soldier) }
+        };
+    }
+    
+    pub fn makeUpdate(soldier: entity.Soldier) Message {
+        return .{
+            .update_entity = .{ .soldier = init(soldier) }
+        };
+    }
+    
+    pub fn makeDespawn(soldier: entity.Soldier) Message {
+        return .{
+            .despawn_entity = .{ .soldier = init(soldier) }
+        };
+    }
+};
+
+pub const Alien = struct {
+    id: entity.id = entity.INVALID_ID,
+    hp: i32,
+    pos: zm.Vec,
+
+    pub fn init(alien: entity.Alien) Alien {
+        return .{
+            .id = alien.id,
+            .pos = alien.pos,
+            .hp = alien.hp,
+        };
+    }
+
+    pub fn makeSpawn(alien: entity.Alien) Message {
+        return .{
+            .spawn_entity = .{ .alien = init(alien) }
+        };
+    }
+    
+    pub fn makeUpdate(alien: entity.Alien) Message {
+        return .{
+            .update_entity = .{ .alien = init(alien) }
+        };
+    }
+
+    pub fn makeDespawn(alien: entity.Alien) Message {
+        return .{
+            .despawn_entity = .{ .alien = init(alien) }
+        };
+    }
+};
+
+test "Protocol" {
+    std.debug.print("Protocol\n", .{});
+
+    const s = entity.Soldier{
+        .hp = 66,
+        .pos = .{1, 2, 3, 4},
+        .vel = .{5, 6, 7, 8},
+    };
+
+    const msg = makeSpawnMessage(s);
+
+    const allocator = std.testing.allocator;
+
+    var aw = try std.ArrayList(u8).initCapacity(allocator, 128);
+    defer aw.deinit(allocator);
+
+    var writer = bits.BitWriter.init(&aw);
+
+    try writer.serialize(allocator, msg);
+
+    var reader = bits.BitReader.init(writer.written());
+
+    const recv = try reader.deserialize(allocator, Message);
+
+    std.debug.print("msg: {}\n", .{msg});
+
+    std.debug.print("recv: {}\n", .{recv});
+
+    try std.testing.expectEqual(msg, recv);
+}