diff --git a/swap/src/alice.rs b/swap/src/alice.rs
index ac46a8ba..d0cedd23 100644
--- a/swap/src/alice.rs
+++ b/swap/src/alice.rs
@@ -26,13 +26,14 @@ use xmr_btc::{alice::State0, bob, monero};
 
 pub type Swarm = libp2p::Swarm<Alice>;
 
+#[allow(unused_assignments)] // Due to the mutable message0?
 pub async fn swap<R: RngCore + CryptoRng>(
     listen: Multiaddr,
     rng: &mut R,
     redeem_address: ::bitcoin::Address,
     punish_address: ::bitcoin::Address,
 ) -> Result<()> {
-    let message0: Option<bob::Message0> = None;
+    let mut message0: Option<bob::Message0> = None;
     let mut last_amounts: Option<SwapParams> = None;
 
     let mut swarm = new_swarm(listen)?;
@@ -48,10 +49,10 @@ pub async fn swap<R: RngCore + CryptoRng>(
                 last_amounts = Some(p);
                 swarm.send(channel, AliceToBob::Amounts(p));
             }
-            OutEvent::Message0 => {
+            OutEvent::Message0(msg) => {
                 debug!("Got message0 from Bob");
                 // TODO: Do this in a more Rusty/functional way.
-                // message0 = Some(msg);
+                message0 = Some(msg);
                 break;
             }
         };
@@ -79,7 +80,7 @@ pub async fn swap<R: RngCore + CryptoRng>(
 
     let _state1 = match message0 {
         Some(msg) => state0.receive(msg),
-        None => todo!("implement serde on Message0"),
+        None => panic!("should have the message by here"),
     };
 
     tracing::warn!("parking thread ...");
@@ -116,8 +117,7 @@ fn new_swarm(listen: Multiaddr) -> Result<Swarm> {
 pub enum OutEvent {
     ConnectionEstablished(PeerId),
     Request(amounts::OutEvent),
-    // Message0(bob::Message0),
-    Message0,
+    Message0(bob::Message0),
 }
 
 impl From<peer_tracker::OutEvent> for OutEvent {
@@ -139,8 +139,7 @@ impl From<amounts::OutEvent> for OutEvent {
 impl From<message0::OutEvent> for OutEvent {
     fn from(event: message0::OutEvent) -> Self {
         match event {
-            // message0::OutEvent::Msg(msg) => OutEvent::Message0(msg),
-            message0::OutEvent::Msg => OutEvent::Message0,
+            message0::OutEvent::Msg(msg) => OutEvent::Message0(msg),
         }
     }
 }
diff --git a/swap/src/alice/message0.rs b/swap/src/alice/message0.rs
index 699a7114..ad62586c 100644
--- a/swap/src/alice/message0.rs
+++ b/swap/src/alice/message0.rs
@@ -7,6 +7,7 @@ use libp2p::{
     swarm::{NetworkBehaviourAction, NetworkBehaviourEventProcess, PollParameters},
     NetworkBehaviour,
 };
+use rand::rngs::OsRng;
 use std::{
     collections::VecDeque,
     task::{Context, Poll},
@@ -15,12 +16,11 @@ use std::{
 use tracing::error;
 
 use crate::network::request_response::{AliceToBob, BobToAlice, Codec, Protocol};
-use xmr_btc::alice::State0;
+use xmr_btc::{alice::State0, bob};
 
 #[derive(Debug)]
 pub enum OutEvent {
-    // Msg(bob::Message0),
-    Msg,
+    Msg(bob::Message0),
 }
 
 /// A `NetworkBehaviour` that represents getting the amounts of an XMR/BTC swap.
@@ -85,18 +85,17 @@ impl NetworkBehaviourEventProcess<RequestResponseEvent<BobToAlice, AliceToBob>>
                         channel,
                     },
             } => match request {
-                BobToAlice::Message0 => {
+                BobToAlice::Message0(msg) => {
                     let response = match &self.state {
                         None => panic!("No state, did you forget to set it?"),
-                        Some(_state) => {
+                        Some(state) => {
                             // TODO: Get OsRng from somewhere?
-                            // AliceToBob::Message0(state.next_message(&mut OsRng))
-                            AliceToBob::Message0
+                            AliceToBob::Message0(state.next_message(&mut OsRng))
                         }
                     };
                     self.rr.send_response(channel, response);
 
-                    self.events.push_back(OutEvent::Msg);
+                    self.events.push_back(OutEvent::Msg(msg));
                 }
                 _ => panic!("unexpected request"),
             },
diff --git a/swap/src/bob.rs b/swap/src/bob.rs
index 4504b3c9..ed38cf87 100644
--- a/swap/src/bob.rs
+++ b/swap/src/bob.rs
@@ -23,6 +23,7 @@ use crate::{
     Cmd, Rsp, PUNISH_TIMELOCK, REFUND_TIMELOCK,
 };
 use xmr_btc::{
+    alice,
     bitcoin::BuildTxLockPsbt,
     bob::{self, State0},
 };
@@ -33,7 +34,7 @@ pub async fn swap<W>(
     mut cmd_tx: Sender<Cmd>,
     mut rsp_rx: Receiver<Rsp>,
     refund_address: ::bitcoin::Address,
-    _wallet: W,
+    wallet: W,
 ) -> Result<()>
 where
     W: BuildTxLockPsbt + Send + Sync + 'static,
@@ -81,10 +82,8 @@ where
     );
     swarm.send_message0(alice.clone(), state0.next_message(rng));
     let _state1 = match swarm.next().await {
-        OutEvent::Message0 => {
-            // state0.receive(wallet, msg) // TODO: More graceful error
-            // handling.
-            println!("TODO: receive after serde is done for Message0")
+        OutEvent::Message0(msg) => {
+            state0.receive(&wallet, msg) // TODO: More graceful error handling.
         }
         other => panic!("unexpected event: {:?}", other),
     };
@@ -120,8 +119,7 @@ fn new_swarm() -> Result<Swarm> {
 pub enum OutEvent {
     ConnectionEstablished(PeerId),
     Amounts(amounts::OutEvent),
-    // Message0(alice::Message0),
-    Message0,
+    Message0(alice::Message0),
 }
 
 impl From<peer_tracker::OutEvent> for OutEvent {
@@ -143,8 +141,7 @@ impl From<amounts::OutEvent> for OutEvent {
 impl From<message0::OutEvent> for OutEvent {
     fn from(event: message0::OutEvent) -> Self {
         match event {
-            // message0::OutEvent::Msg(msg) => OutEvent::Message0(msg),
-            message0::OutEvent::Msg => OutEvent::Message0,
+            message0::OutEvent::Msg(msg) => OutEvent::Message0(msg),
         }
     }
 }
diff --git a/swap/src/bob/amounts.rs b/swap/src/bob/amounts.rs
index 18071985..4443a1e1 100644
--- a/swap/src/bob/amounts.rs
+++ b/swap/src/bob/amounts.rs
@@ -85,7 +85,7 @@ impl NetworkBehaviourEventProcess<RequestResponseEvent<BobToAlice, AliceToBob>>
                     },
             } => match response {
                 AliceToBob::Amounts(p) => self.events.push_back(OutEvent::Amounts(p)),
-                AliceToBob::Message0 => panic!("shouldn't get message0 here"),
+                AliceToBob::Message0(_) => panic!("shouldn't get message0 here"),
             },
 
             RequestResponseEvent::InboundFailure { .. } => {
diff --git a/swap/src/bob/message0.rs b/swap/src/bob/message0.rs
index 7aba6f23..8e3a0ad8 100644
--- a/swap/src/bob/message0.rs
+++ b/swap/src/bob/message0.rs
@@ -14,12 +14,11 @@ use std::{
 use tracing::error;
 
 use crate::network::request_response::{AliceToBob, BobToAlice, Codec, Protocol};
-use xmr_btc::bob;
+use xmr_btc::{alice, bob};
 
 #[derive(Debug)]
 pub enum OutEvent {
-    // Msg(alice::Message0),
-    Msg,
+    Msg(alice::Message0),
 }
 
 /// A `NetworkBehaviour` that represents send/recv of message 0.
@@ -47,9 +46,8 @@ impl Message0 {
         }
     }
 
-    pub fn send(&mut self, alice: PeerId, _msg: bob::Message0) {
-        // let msg = BobToAlice::Message0(msg);
-        let msg = BobToAlice::Message0;
+    pub fn send(&mut self, alice: PeerId, msg: bob::Message0) {
+        let msg = BobToAlice::Message0(msg);
         let _id = self.rr.send_request(&alice, msg);
     }
 
@@ -81,8 +79,7 @@ impl NetworkBehaviourEventProcess<RequestResponseEvent<BobToAlice, AliceToBob>>
                         request_id: _,
                     },
             } => match response {
-                // AliceToBob::Message0(msg) => self.events.push_back(OutEvent::Msg(msg)),
-                AliceToBob::Message0 => self.events.push_back(OutEvent::Msg),
+                AliceToBob::Message0(msg) => self.events.push_back(OutEvent::Msg(msg)),
                 AliceToBob::Amounts(_) => panic!("shouldn't get amounts here"),
             },
 
diff --git a/swap/src/network/request_response.rs b/swap/src/network/request_response.rs
index 86420bee..b6e582c5 100644
--- a/swap/src/network/request_response.rs
+++ b/swap/src/network/request_response.rs
@@ -8,27 +8,27 @@ use serde::{Deserialize, Serialize};
 use std::{fmt::Debug, io};
 
 use crate::SwapParams;
-use xmr_btc::monero;
+use xmr_btc::{alice, bob, monero};
 
 /// Time to wait for a response back once we send a request.
 pub const TIMEOUT: u64 = 3600; // One hour.
 
 /// Messages Bob sends to Alice.
 #[derive(Clone, Debug, Serialize, Deserialize)]
+#[allow(clippy::large_enum_variant)]
 pub enum BobToAlice {
     #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
     AmountsFromBtc(::bitcoin::Amount),
     AmountsFromXmr(monero::Amount),
-    Message0,
-    // Message0(bob::Message0),
+    Message0(bob::Message0),
 }
 
 /// Messages Alice sends to Bob.
 #[derive(Clone, Debug, Serialize, Deserialize)]
+#[allow(clippy::large_enum_variant)]
 pub enum AliceToBob {
     Amounts(SwapParams),
-    Message0,
-    // Message0(alice::Message0),
+    Message0(alice::Message0),
 }
 
 #[derive(Debug, Clone, Copy, Default)]
diff --git a/xmr-btc/src/alice/message.rs b/xmr-btc/src/alice/message.rs
index 052731b1..ada3636f 100644
--- a/xmr-btc/src/alice/message.rs
+++ b/xmr-btc/src/alice/message.rs
@@ -1,8 +1,9 @@
 use anyhow::Result;
 use ecdsa_fun::{adaptor::EncryptedSignature, Signature};
+use serde::{Deserialize, Serialize};
 use std::convert::TryFrom;
 
-use crate::{bitcoin, monero};
+use crate::{bitcoin, monero, serde::cross_curve_dleq_proof};
 
 #[derive(Debug)]
 pub enum Message {
@@ -11,11 +12,12 @@ pub enum Message {
     Message2(Message2),
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct Message0 {
     pub(crate) A: bitcoin::PublicKey,
     pub(crate) S_a_monero: monero::PublicKey,
     pub(crate) S_a_bitcoin: bitcoin::PublicKey,
+    #[serde(with = "cross_curve_dleq_proof")]
     pub(crate) dleq_proof_s_a: cross_curve_dleq::Proof,
     pub(crate) v_a: monero::PrivateViewKey,
     pub(crate) redeem_address: bitcoin::Address,
diff --git a/xmr-btc/src/bob/message.rs b/xmr-btc/src/bob/message.rs
index f45c3b92..465241f6 100644
--- a/xmr-btc/src/bob/message.rs
+++ b/xmr-btc/src/bob/message.rs
@@ -1,6 +1,7 @@
-use crate::{bitcoin, monero};
+use crate::{bitcoin, monero, serde::cross_curve_dleq_proof};
 use anyhow::Result;
 use ecdsa_fun::{adaptor::EncryptedSignature, Signature};
+use serde::{Deserialize, Serialize};
 use std::convert::TryFrom;
 
 #[derive(Clone, Debug)]
@@ -11,11 +12,12 @@ pub enum Message {
     Message3(Message3),
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct Message0 {
     pub(crate) B: bitcoin::PublicKey,
     pub(crate) S_b_monero: monero::PublicKey,
     pub(crate) S_b_bitcoin: bitcoin::PublicKey,
+    #[serde(with = "cross_curve_dleq_proof")]
     pub(crate) dleq_proof_s_b: cross_curve_dleq::Proof,
     pub(crate) v_b: monero::PrivateViewKey,
     pub(crate) refund_address: bitcoin::Address,
diff --git a/xmr-btc/src/serde.rs b/xmr-btc/src/serde.rs
index e64cfd10..5e6e7052 100644
--- a/xmr-btc/src/serde.rs
+++ b/xmr-btc/src/serde.rs
@@ -88,6 +88,44 @@ pub mod cross_curve_dleq_scalar {
     }
 }
 
+pub mod cross_curve_dleq_proof {
+    use serde::{de, de::Visitor, Deserializer, Serializer};
+    use std::fmt;
+
+    struct MyVisitor;
+
+    impl<'de> Visitor<'de> for MyVisitor {
+        type Value = cross_curve_dleq::Proof;
+
+        fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+            write!(formatter, "todo")
+        }
+
+        fn visit_bytes<E>(self, _s: &[u8]) -> Result<Self::Value, E>
+        where
+            E: de::Error,
+        {
+            todo!("visit_bytes")
+        }
+    }
+
+    pub fn serialize<S>(_x: &cross_curve_dleq::Proof, _s: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        todo!("serialize")
+    }
+
+    pub fn deserialize<'de, D>(
+        _deserializer: D,
+    ) -> Result<cross_curve_dleq::Proof, <D as Deserializer<'de>>::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        todo!("deserialize")
+    }
+}
+
 pub mod monero_private_key {
     use serde::{de, de::Visitor, Deserializer, Serializer};
     use std::fmt;