diff --git a/Cargo.lock b/Cargo.lock
index eb6a60b..0b67fec 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -189,6 +189,7 @@ dependencies = [
  "tracing",
  "tracing-appender",
  "tracing-subscriber",
+ "uuid",
 ]
 
 [[package]]
@@ -330,6 +331,18 @@ dependencies = [
  "slab",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43a49c392881ce6d5c3b8cb70f98717b7c07aabbdff06687b9030dbfbe2725f8"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi 0.13.3+wasi-0.2.2",
+ "windows-targets",
+]
+
 [[package]]
 name = "gimli"
 version = "0.31.1"
@@ -426,7 +439,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2886843bf800fba2e3377cff24abf6379b4c4d5c6681eaf9ea5b0d15090450bd"
 dependencies = [
  "libc",
- "wasi",
+ "wasi 0.11.0+wasi-snapshot-preview1",
  "windows-sys 0.52.0",
 ]
 
@@ -909,6 +922,15 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
+[[package]]
+name = "uuid"
+version = "1.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ced87ca4be083373936a67f8de945faa23b6b42384bd5b64434850802c6dccd0"
+dependencies = [
+ "getrandom",
+]
+
 [[package]]
 name = "valuable"
 version = "0.1.1"
@@ -921,6 +943,15 @@ version = "0.11.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
+[[package]]
+name = "wasi"
+version = "0.13.3+wasi-0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "26816d2e1a4a36a2940b96c5296ce403917633dff8f3440e9b236ed6f6bacad2"
+dependencies = [
+ "wit-bindgen-rt",
+]
+
 [[package]]
 name = "winapi"
 version = "0.3.9"
@@ -1033,3 +1064,12 @@ checksum = "59690dea168f2198d1a3b0cac23b8063efcd11012f10ae4698f284808c8ef603"
 dependencies = [
  "memchr",
 ]
+
+[[package]]
+name = "wit-bindgen-rt"
+version = "0.33.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3268f3d866458b787f390cf61f4bbb563b922d091359f9608842999eaee3943c"
+dependencies = [
+ "bitflags",
+]
diff --git a/Cargo.toml b/Cargo.toml
index 42d7893..34a36bf 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -37,3 +37,4 @@ toml = "0.8.19"
 tracing = { version = "0.1.37", features = ["log"] }
 tracing-subscriber = { version = "0.3.17", features = ["tracing-log"] }
 tracing-appender = "0.2.2"
+uuid = { version = "1.13.1", features = ["v4"] }
diff --git a/src/protocol/packets.rs b/src/protocol/packets.rs
index 7e577e5..0a845d4 100644
--- a/src/protocol/packets.rs
+++ b/src/protocol/packets.rs
@@ -2,6 +2,8 @@
 
 // Inspired by https://github.com/iceiix/stevenarella.
 
+use tracing::trace;
+
 /// Enum representation of a packet's direction.
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub enum PacketDirection {
@@ -62,7 +64,9 @@ macro_rules! packets {
                             ClientState::Disconnected => false,
                         }
                     })(packet_body)?;
+                    trace!("Parsing packet: {:?} {:?} {:02x} ({} bytes)", direction, client_state, *packet_id, packet_body.len());
                     let (_, packet) = Packet::body_parser(client_state, direction, packet_id)(packet_body)?;
+                    // trace!("Parsed packet: {:?}", packet);
                     Ok((input, packet))
                 }
             }
diff --git a/src/protocol/parsing.rs b/src/protocol/parsing.rs
index fa5f2e1..7c4a027 100644
--- a/src/protocol/parsing.rs
+++ b/src/protocol/parsing.rs
@@ -114,24 +114,13 @@ pub trait Parsable {
 impl<T: Parsable + std::fmt::Debug> Parsable for Option<T> {
     #[tracing::instrument]
     fn parse(data: &[u8]) -> IResult<&[u8], Self> {
-        let (data, exists) = bool::parse(data)?;
-        if exists {
-            let (data, thing) = T::parse(data)?;
-            Ok((data, Some(thing)))
-        } else {
-            Ok((data, None))
-        }
+        nom::combinator::opt(T::parse)(data)
     }
     #[tracing::instrument]
     fn serialize(&self) -> Vec<u8> {
         match self {
-            Some(t) => {
-                let mut output = vec![];
-                output.extend(true.serialize());
-                output.extend(t.serialize());
-                output
-            }
-            None => false.serialize(),
+            Some(t) => t.serialize(),
+            None => Vec::new(),
         }
     }
 }
@@ -151,6 +140,16 @@ impl<T: Parsable + std::fmt::Debug> Parsable for Vec<T> {
     }
 }
 
+impl Parsable for uuid::Uuid {
+    #[tracing::instrument]
+    fn parse(data: &[u8]) -> IResult<&[u8], Self> {
+        map_res(take(16usize), uuid::Uuid::from_slice)(data)
+    }
+    #[tracing::instrument]
+    fn serialize(&self) -> Vec<u8> {
+        self.as_bytes().to_vec()
+    }
+}
 impl Parsable for serde_json::Value {
     #[tracing::instrument]
     fn parse(data: &[u8]) -> IResult<&[u8], Self> {
diff --git a/src/protocol/types.rs b/src/protocol/types.rs
index 978d5d8..a0ce8dd 100644
--- a/src/protocol/types.rs
+++ b/src/protocol/types.rs
@@ -1,7 +1,8 @@
 use crate::protocol::parsing::{IResult, Parsable};
+pub use uuid::Uuid;
 
-/// Alias for a u128.
-pub type Uuid = u128;
+// /// Alias for a u128.
+// pub type Uuid = u128;
 pub use crate::protocol::parsing::VarInt;
 /// Alias for a `serde_json::Value`.
 pub type Json = serde_json::Value;
diff --git a/src/server/mod.rs b/src/server/mod.rs
index be03275..655fd06 100644
--- a/src/server/mod.rs
+++ b/src/server/mod.rs
@@ -15,6 +15,7 @@ use tokio::net::{TcpListener, ToSocketAddrs};
 use tokio::{sync::RwLock, task::JoinHandle};
 use tokio_util::sync::CancellationToken;
 use tracing::{error, trace};
+use crate::protocol::types::Uuid;
 
 /// The main state and logic of the program.
 #[derive(Debug)]
@@ -270,7 +271,7 @@ impl App for Server {
                         // TODO: Get the user from the stored database.
                         // TODO: Encryption/compression.
                         client.queue_packet(LoginSuccess {
-                            uuid: login_start.uuid.unwrap_or(0u128),
+                            uuid: login_start.uuid.unwrap_or(Uuid::nil()),
                             username: login_start.name.clone(),
                             properties: vec![],
                         });