diff --git a/Cargo.lock b/Cargo.lock
index 8a15b72..df88fd2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1638,6 +1638,7 @@ dependencies = [
  "bitvec",
  "byteorder",
  "bytes",
+ "itertools",
  "librqbit-bencode",
  "librqbit-buffers",
  "librqbit-clone-to-owned",
@@ -2598,9 +2599,9 @@ checksum = "583034fd73374156e66797ed8e5b0d5690409c9226b22d87cb7f19821c05d152"
 
 [[package]]
 name = "rustix"
-version = "0.38.34"
+version = "0.38.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70dc5ec042f7a43c4a73241207cecc9873a06d45debb38b329f8541d85c2730f"
+checksum = "a85d50532239da68e9addb745ba38ff4612a242c1c7ceea689c4bc7c2f43c36f"
 dependencies = [
  "bitflags 2.6.0",
  "errno",
@@ -2641,9 +2642,9 @@ checksum = "fc0a2ce646f8655401bb81e7927b812614bd5d91dbc968696be50603510fcaf0"
 
 [[package]]
 name = "rustls-webpki"
-version = "0.102.6"
+version = "0.102.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e6b52d4fda176fd835fdc55a835d4a89b8499cad995885a21149d5ad62f852e"
+checksum = "84678086bd54edf2b415183ed7a94d0efb049f1b646a33e22a36f3794be6ae56"
 dependencies = [
  "ring",
  "rustls-pki-types",
diff --git a/crates/buffers/src/lib.rs b/crates/buffers/src/lib.rs
index 814e843..f6cae86 100644
--- a/crates/buffers/src/lib.rs
+++ b/crates/buffers/src/lib.rs
@@ -3,8 +3,10 @@
 //
 // Not useful outside of librqbit.
 
+use std::borrow::Borrow;
+
 use bytes::Bytes;
-use serde::{Deserialize, Deserializer};
+use serde::{Deserialize, Deserializer, Serialize};
 
 use clone_to_owned::CloneToOwned;
 
@@ -15,7 +17,9 @@ pub struct ByteBufOwned(pub bytes::Bytes);
 #[serde(transparent)]
 pub struct ByteBuf<'a>(pub &'a [u8]);
 
-pub trait ByteBufT {
+pub trait ByteBufT:
+    AsRef<[u8]> + std::hash::Hash + Serialize + Eq + core::fmt::Debug + CloneToOwned + Borrow<[u8]>
+{
     fn as_slice(&self) -> &[u8];
 }
 
diff --git a/crates/librqbit/src/peer_connection.rs b/crates/librqbit/src/peer_connection.rs
index 8401ae8..9b3ae73 100644
--- a/crates/librqbit/src/peer_connection.rs
+++ b/crates/librqbit/src/peer_connection.rs
@@ -14,10 +14,7 @@ use librqbit_core::{
 };
 use parking_lot::RwLock;
 use peer_binary_protocol::{
-    extended::{
-        handshake::{ExtendedHandshake, YourIP},
-        ExtendedMessage,
-    },
+    extended::{handshake::ExtendedHandshake, ExtendedMessage},
     serialize_piece_preamble, Handshake, Message, MessageOwned, PIECE_MESSAGE_DEFAULT_LEN,
 };
 use serde::{Deserialize, Serialize};
@@ -248,14 +245,14 @@ impl<H: PeerConnectionHandler> PeerConnection<H> {
         let supports_extended = handshake_supports_extended;
 
         if supports_extended {
-            let your_ip = self.addr.ip();
             let mut my_extended = ExtendedHandshake::new();
-            my_extended.yourip = Some(YourIP(your_ip));
             self.handler
                 .update_my_extended_handshake(&mut my_extended)?;
             let my_extended = Message::Extended(ExtendedMessage::Handshake(my_extended));
             trace!("sending extended handshake: {:?}", &my_extended);
-            my_extended.serialize(&mut write_buf, &|| None).unwrap();
+            my_extended
+                .serialize(&mut write_buf, &Default::default)
+                .unwrap();
             with_timeout(rwtimeout, conn.write_all(&write_buf))
                 .await
                 .context("error writing extended handshake")?;
@@ -318,7 +315,8 @@ impl<H: PeerConnectionHandler> PeerConnection<H> {
                         extended_handshake_ref
                             .read()
                             .as_ref()
-                            .and_then(|e| e.ut_metadata())
+                            .map(|e| e.peer_extended_messages())
+                            .unwrap_or_default()
                     })?,
                     WriterRequest::ReadChunkRequest(chunk) => {
                         #[allow(unused_mut)]
@@ -397,7 +395,6 @@ impl<H: PeerConnectionHandler> PeerConnection<H> {
                 if let Message::Extended(ExtendedMessage::Handshake(h)) = &message {
                     *extended_handshake_ref.write() = Some(h.clone_to_owned(None));
                     self.handler.on_extended_handshake(h)?;
-                    trace!("remembered extended handshake for future serializing");
                 } else {
                     self.handler
                         .on_received_message(message)
diff --git a/crates/librqbit/src/read_buf.rs b/crates/librqbit/src/read_buf.rs
index 2d57007..4b1428e 100644
--- a/crates/librqbit/src/read_buf.rs
+++ b/crates/librqbit/src/read_buf.rs
@@ -57,7 +57,7 @@ impl ReadBuf {
             anyhow::bail!("peer disconnected while reading handshake");
         }
         let (h, size) = Handshake::deserialize(&self.buf[..self.filled])
-            .map_err(|e| anyhow::anyhow!("error deserializing handshake: {:?}", e))?;
+            .map_err(|e| anyhow::anyhow!("error deserializing handshake: {:?} hadshake data {:?}", e, &self.buf[..self.filled.min(19)]))?;
         self.processed = size;
         Ok(h)
     }
diff --git a/crates/librqbit/src/torrent_state/live/mod.rs b/crates/librqbit/src/torrent_state/live/mod.rs
index 385dd56..6afa729 100644
--- a/crates/librqbit/src/torrent_state/live/mod.rs
+++ b/crates/librqbit/src/torrent_state/live/mod.rs
@@ -67,7 +67,12 @@ use librqbit_core::{
 };
 use parking_lot::{RwLock, RwLockReadGuard, RwLockWriteGuard};
 use peer_binary_protocol::{
-    extended::{handshake::ExtendedHandshake, ut_metadata::UtMetadata, ExtendedMessage},
+    extended::{
+        handshake::{ExtendedHandshake, YourIP},
+        ut_metadata::UtMetadata,
+        ut_pex::UtPex,
+        ExtendedMessage,
+    },
     Handshake, Message, MessageOwned, Piece, Request,
 };
 use peers::stats::atomic::AggregatePeerStatsAtomic;
@@ -877,6 +882,9 @@ impl<'a> PeerConnectionHandler for &'a PeerHandler {
                 self.send_metadata_piece(metadata_piece_id)
                     .with_context(|| format!("error sending metadata piece {metadata_piece_id}"))?;
             }
+            Message::Extended(ExtendedMessage::UtPex(pex)) => {
+                self.on_pex_message(pex);
+            }
             message => {
                 warn!("received unsupported message {:?}, ignoring", message);
             }
@@ -887,7 +895,7 @@ impl<'a> PeerConnectionHandler for &'a PeerHandler {
     fn serialize_bitfield_message_to_buf(&self, buf: &mut Vec<u8>) -> anyhow::Result<usize> {
         let g = self.state.lock_read("serialize_bitfield_message_to_buf");
         let msg = Message::Bitfield(ByteBuf(g.get_chunks()?.get_have_pieces().as_bytes()));
-        let len = msg.serialize(buf, &|| None)?;
+        let len = msg.serialize(buf, &Default::default)?;
         trace!("sending: {:?}, length={}", &msg, len);
         Ok(len)
     }
@@ -914,7 +922,10 @@ impl<'a> PeerConnectionHandler for &'a PeerHandler {
         self.state.file_ops().read_chunk(self.addr, chunk, buf)
     }
 
-    fn on_extended_handshake(&self, _: &ExtendedHandshake<ByteBuf>) -> anyhow::Result<()> {
+    fn on_extended_handshake(&self, hs: &ExtendedHandshake<ByteBuf>) -> anyhow::Result<()> {
+        if let Some(peer_pex_msg_id) = hs.ut_pex() {
+            trace!("peer supports pex at {peer_pex_msg_id}");
+        }
         Ok(())
     }
 
@@ -937,6 +948,8 @@ impl<'a> PeerConnectionHandler for &'a PeerHandler {
         &self,
         handshake: &mut ExtendedHandshake<ByteBuf>,
     ) -> anyhow::Result<()> {
+        let your_ip = self.addr.ip();
+        handshake.yourip = Some(YourIP(your_ip));
         let info_bytes = &self.state.torrent().info_bytes;
         if !info_bytes.is_empty() {
             if let Ok(len) = info_bytes.len().try_into() {
@@ -1659,4 +1672,20 @@ impl PeerHandler {
             .context("error sending UtMetadata: channel closed")?;
         Ok(())
     }
+
+    fn on_pex_message<B>(&self, msg: UtPex<B>)
+    where
+        B: AsRef<[u8]> + std::fmt::Debug,
+    {
+        // TODO: this is just first attempt at pex - will need more sophistication on adding peers - BEP 40,  check number of live, seen peers ...
+        msg.added_peers().for_each(|peer| {
+            self.state
+                .add_peer_if_not_seen(peer.addr)
+                .map_err(|error| {
+                    warn!(?peer, ?error, "failed to add peer");
+                    error
+                })
+                .ok();
+        });
+    }
 }
diff --git a/crates/peer_binary_protocol/Cargo.toml b/crates/peer_binary_protocol/Cargo.toml
index 4c2ebc5..4ef36a9 100644
--- a/crates/peer_binary_protocol/Cargo.toml
+++ b/crates/peer_binary_protocol/Cargo.toml
@@ -20,3 +20,4 @@ librqbit-core = { path = "../librqbit_core", default-features = false, version =
 bitvec = "1"
 anyhow = "1"
 bytes = "1.7.1"
+itertools = "0.12"
diff --git a/crates/peer_binary_protocol/src/extended/handshake.rs b/crates/peer_binary_protocol/src/extended/handshake.rs
index 7cc05df..721fff8 100644
--- a/crates/peer_binary_protocol/src/extended/handshake.rs
+++ b/crates/peer_binary_protocol/src/extended/handshake.rs
@@ -1,19 +1,18 @@
-use std::{
-    collections::HashMap,
-    net::{IpAddr, Ipv4Addr, Ipv6Addr},
-};
+use std::{collections::HashMap, net::IpAddr};
 
-use buffers::ByteBuf;
-use byteorder::ByteOrder;
-use byteorder::BE;
+use buffers::{ByteBuf, ByteBufT};
 use bytes::Bytes;
 use clone_to_owned::CloneToOwned;
 use serde::{Deserialize, Deserializer, Serialize};
 
-use crate::{EXTENDED_UT_METADATA_KEY, MY_EXTENDED_UT_METADATA};
+use crate::{
+    EXTENDED_UT_METADATA_KEY, EXTENDED_UT_PEX_KEY, MY_EXTENDED_UT_METADATA, MY_EXTENDED_UT_PEX,
+};
+
+use super::PeerExtendedMessageIds;
 
 #[derive(Deserialize, Serialize, Debug, Default)]
-pub struct ExtendedHandshake<ByteBuf: Eq + std::hash::Hash> {
+pub struct ExtendedHandshake<ByteBuf: ByteBufT> {
     #[serde(bound(deserialize = "ByteBuf: From<&'de [u8]>"))]
     pub m: HashMap<ByteBuf, u8>,
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -40,6 +39,7 @@ impl ExtendedHandshake<ByteBuf<'static>> {
     pub fn new() -> Self {
         let mut features = HashMap::new();
         features.insert(ByteBuf(EXTENDED_UT_METADATA_KEY), MY_EXTENDED_UT_METADATA);
+        features.insert(ByteBuf(EXTENDED_UT_PEX_KEY), MY_EXTENDED_UT_PEX);
         Self {
             m: features,
             ..Default::default()
@@ -49,7 +49,7 @@ impl ExtendedHandshake<ByteBuf<'static>> {
 
 impl<'a, ByteBuf> ExtendedHandshake<ByteBuf>
 where
-    ByteBuf: Eq + std::hash::Hash + std::borrow::Borrow<[u8]>,
+    ByteBuf: ByteBufT,
 {
     fn get_msgid(&self, msg_type: &'a [u8]) -> Option<u8> {
         self.m.get(msg_type).copied()
@@ -58,12 +58,23 @@ where
     pub fn ut_metadata(&self) -> Option<u8> {
         self.get_msgid(EXTENDED_UT_METADATA_KEY)
     }
+
+    pub fn ut_pex(&self) -> Option<u8> {
+        self.get_msgid(EXTENDED_UT_PEX_KEY)
+    }
+
+    pub fn peer_extended_messages(&self) -> PeerExtendedMessageIds {
+        PeerExtendedMessageIds {
+            ut_metadata: self.ut_metadata(),
+            ut_pex: self.ut_pex(),
+        }
+    }
 }
 
 impl<ByteBuf> CloneToOwned for ExtendedHandshake<ByteBuf>
 where
-    ByteBuf: CloneToOwned + Eq + std::hash::Hash,
-    <ByteBuf as CloneToOwned>::Target: Eq + std::hash::Hash,
+    ByteBuf: ByteBufT,
+    <ByteBuf as CloneToOwned>::Target: ByteBufT,
 {
     type Target = ExtendedHandshake<<ByteBuf as CloneToOwned>::Target>;
 
@@ -122,18 +133,11 @@ impl<'de> Deserialize<'de> for YourIP {
                 E: serde::de::Error,
             {
                 if v.len() == 4 {
-                    return Ok(YourIP(IpAddr::V4(Ipv4Addr::new(v[0], v[1], v[2], v[3]))));
+                    let ip_bytes: &[u8; 4] = v[0..4].try_into().unwrap(); // Safe to unwrap as we check slice length
+                    return Ok(YourIP(IpAddr::from(*ip_bytes)));
                 } else if v.len() == 16 {
-                    return Ok(YourIP(IpAddr::V6(Ipv6Addr::new(
-                        BE::read_u16(&v[..2]),
-                        BE::read_u16(&v[2..4]),
-                        BE::read_u16(&v[4..6]),
-                        BE::read_u16(&v[6..8]),
-                        BE::read_u16(&v[8..10]),
-                        BE::read_u16(&v[10..12]),
-                        BE::read_u16(&v[12..14]),
-                        BE::read_u16(&v[14..]),
-                    ))));
+                    let ip_bytes: &[u8; 16] = v[0..16].try_into().unwrap(); // Safe to unwrap as we check slice length
+                    return Ok(YourIP(IpAddr::from(*ip_bytes)));
                 }
                 Err(E::custom("expected 4 or 16 byte address"))
             }
diff --git a/crates/peer_binary_protocol/src/extended/mod.rs b/crates/peer_binary_protocol/src/extended/mod.rs
index 2ac4607..85296ba 100644
--- a/crates/peer_binary_protocol/src/extended/mod.rs
+++ b/crates/peer_binary_protocol/src/extended/mod.rs
@@ -1,9 +1,13 @@
 use bencode::bencode_serialize_to_writer;
 use bencode::from_bytes;
 use bencode::BencodeValue;
+use buffers::ByteBufT;
 use bytes::Bytes;
 use clone_to_owned::CloneToOwned;
-use serde::{Deserialize, Serialize};
+use serde::Deserialize;
+use ut_pex::UtPex;
+
+use crate::MY_EXTENDED_UT_PEX;
 
 use self::{handshake::ExtendedHandshake, ut_metadata::UtMetadata};
 
@@ -11,20 +15,28 @@ use super::MessageDeserializeError;
 
 pub mod handshake;
 pub mod ut_metadata;
+pub mod ut_pex;
 
 use super::MY_EXTENDED_UT_METADATA;
 
+#[derive(Debug, Default)]
+pub struct PeerExtendedMessageIds {
+    pub ut_metadata: Option<u8>,
+    pub ut_pex: Option<u8>,
+}
+
 #[derive(Debug)]
-pub enum ExtendedMessage<ByteBuf: std::hash::Hash + Eq> {
+pub enum ExtendedMessage<ByteBuf: ByteBufT> {
     Handshake(ExtendedHandshake<ByteBuf>),
     UtMetadata(UtMetadata<ByteBuf>),
+    UtPex(UtPex<ByteBuf>),
     Dyn(u8, BencodeValue<ByteBuf>),
 }
 
 impl<ByteBuf> CloneToOwned for ExtendedMessage<ByteBuf>
 where
-    ByteBuf: CloneToOwned + std::hash::Hash + Eq,
-    <ByteBuf as CloneToOwned>::Target: std::hash::Hash + Eq,
+    ByteBuf: ByteBufT,
+    <ByteBuf as CloneToOwned>::Target: ByteBufT,
 {
     type Target = ExtendedMessage<<ByteBuf as CloneToOwned>::Target>;
 
@@ -37,15 +49,16 @@ where
             ExtendedMessage::UtMetadata(m) => {
                 ExtendedMessage::UtMetadata(m.clone_to_owned(within_buffer))
             }
+            ExtendedMessage::UtPex(m) => ExtendedMessage::UtPex(m.clone_to_owned(within_buffer)),
         }
     }
 }
 
-impl<'a, ByteBuf: 'a + std::hash::Hash + Eq + Serialize> ExtendedMessage<ByteBuf> {
+impl<ByteBuf: ByteBufT> ExtendedMessage<ByteBuf> {
     pub fn serialize(
         &self,
         out: &mut Vec<u8>,
-        extended_handshake_ut_metadata: &dyn Fn() -> Option<u8>,
+        extended_handshake_ut_metadata: &dyn Fn() -> PeerExtendedMessageIds,
     ) -> anyhow::Result<()>
     where
         ByteBuf: AsRef<[u8]>,
@@ -60,17 +73,28 @@ impl<'a, ByteBuf: 'a + std::hash::Hash + Eq + Serialize> ExtendedMessage<ByteBuf
                 bencode_serialize_to_writer(h, out)?;
             }
             ExtendedMessage::UtMetadata(u) => {
-                let emsg_id = extended_handshake_ut_metadata().ok_or_else(|| {
-                    anyhow::anyhow!("need peer's handshake to serialize ut_metadata")
-                })?;
+                let emsg_id = extended_handshake_ut_metadata()
+                    .ut_metadata
+                    .ok_or_else(|| {
+                        anyhow::anyhow!("need peer's handshake to serialize ut_metadata")
+                    })?;
                 out.push(emsg_id);
                 u.serialize(out);
             }
+            ExtendedMessage::UtPex(m) => {
+                let emsg_id = extended_handshake_ut_metadata().ut_pex.ok_or_else(|| {
+                    anyhow::anyhow!(
+                        "need peer's handshake to serialize ut_pex, or peer does't support ut_pex"
+                    )
+                })?;
+                out.push(emsg_id);
+                bencode_serialize_to_writer(m, out)?;
+            }
         }
         Ok(())
     }
 
-    pub fn deserialize(mut buf: &'a [u8]) -> Result<Self, MessageDeserializeError>
+    pub fn deserialize<'a>(mut buf: &'a [u8]) -> Result<Self, MessageDeserializeError>
     where
         ByteBuf: Deserialize<'a> + From<&'a [u8]>,
     {
@@ -91,6 +115,7 @@ impl<'a, ByteBuf: 'a + std::hash::Hash + Eq + Serialize> ExtendedMessage<ByteBuf
             MY_EXTENDED_UT_METADATA => {
                 Ok(ExtendedMessage::UtMetadata(UtMetadata::deserialize(buf)?))
             }
+            MY_EXTENDED_UT_PEX => Ok(ExtendedMessage::UtPex(from_bytes(buf)?)),
             _ => Ok(ExtendedMessage::Dyn(emsg_id, from_bytes(buf)?)),
         }
     }
diff --git a/crates/peer_binary_protocol/src/extended/ut_metadata.rs b/crates/peer_binary_protocol/src/extended/ut_metadata.rs
index ac7e58b..face0bd 100644
--- a/crates/peer_binary_protocol/src/extended/ut_metadata.rs
+++ b/crates/peer_binary_protocol/src/extended/ut_metadata.rs
@@ -1,5 +1,6 @@
 use bencode::bencode_serialize_to_writer;
 use bencode::BencodeDeserializer;
+use buffers::ByteBufT;
 use bytes::Bytes;
 use clone_to_owned::CloneToOwned;
 use serde::Deserialize;
@@ -39,7 +40,7 @@ impl<ByteBuf: CloneToOwned> CloneToOwned for UtMetadata<ByteBuf> {
     }
 }
 
-impl<'a, ByteBuf: 'a> UtMetadata<ByteBuf> {
+impl<ByteBuf: ByteBufT> UtMetadata<ByteBuf> {
     pub fn serialize(&self, buf: &mut Vec<u8>)
     where
         ByteBuf: AsRef<[u8]>,
@@ -83,7 +84,7 @@ impl<'a, ByteBuf: 'a> UtMetadata<ByteBuf> {
             }
         }
     }
-    pub fn deserialize(buf: &'a [u8]) -> Result<Self, MessageDeserializeError>
+    pub fn deserialize<'a>(buf: &'a [u8]) -> Result<Self, MessageDeserializeError>
     where
         ByteBuf: From<&'a [u8]>,
     {
diff --git a/crates/peer_binary_protocol/src/extended/ut_pex.rs b/crates/peer_binary_protocol/src/extended/ut_pex.rs
new file mode 100644
index 0000000..73698f2
--- /dev/null
+++ b/crates/peer_binary_protocol/src/extended/ut_pex.rs
@@ -0,0 +1,151 @@
+use std::net::{IpAddr, SocketAddr};
+
+use byteorder::{ByteOrder, BE};
+use bytes::Bytes;
+use clone_to_owned::CloneToOwned;
+use itertools::{EitherOrBoth, Itertools};
+use serde::{Deserialize, Serialize};
+
+pub struct PexPeerInfo {
+    pub flags: u8,
+    pub addr: SocketAddr,
+}
+
+impl core::fmt::Debug for PexPeerInfo {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.addr)?;
+        if self.flags != 0 {
+            write!(f, ";flags={}", self.flags)?;
+        }
+        Ok(())
+    }
+}
+
+#[derive(Serialize, Default, Deserialize)]
+pub struct UtPex<B> {
+    added: B,
+    #[serde(rename = "added.f")]
+    #[serde(skip_serializing_if = "Option::is_none")]
+    added_f: Option<B>,
+    added6: B,
+    #[serde(rename = "added6.f")]
+    #[serde(skip_serializing_if = "Option::is_none")]
+    added6_f: Option<B>,
+    dropped: B,
+    dropped6: B,
+}
+
+impl<B> core::fmt::Debug for UtPex<B>
+where
+    B: AsRef<[u8]>,
+{
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        struct IterDebug<I>(I);
+        impl<I> core::fmt::Debug for IterDebug<I>
+        where
+            I: Iterator<Item = PexPeerInfo> + Clone,
+        {
+            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                f.debug_list().entries(self.0.clone()).finish()
+            }
+        }
+        f.debug_struct("UtPex")
+            .field("added", &IterDebug(self.added_peers()))
+            .field("dropped", &IterDebug(self.dropped_peers()))
+            .finish()
+    }
+}
+
+impl<B> CloneToOwned for UtPex<B>
+where
+    B: CloneToOwned,
+{
+    type Target = UtPex<<B as CloneToOwned>::Target>;
+    fn clone_to_owned(&self, within_buffer: Option<&Bytes>) -> Self::Target {
+        UtPex {
+            added: self.added.clone_to_owned(within_buffer),
+            added_f: self.added_f.clone_to_owned(within_buffer),
+            added6: self.added6.clone_to_owned(within_buffer),
+            added6_f: self.added6_f.clone_to_owned(within_buffer),
+            dropped: self.dropped.clone_to_owned(within_buffer),
+            dropped6: self.dropped6.clone_to_owned(within_buffer),
+        }
+    }
+}
+
+impl<B> UtPex<B>
+where
+    B: AsRef<[u8]>,
+{
+    fn added_peers_inner<'a>(
+        &'a self,
+        buf: &'a B,
+        flags: &'a Option<B>,
+        ip_len: usize,
+    ) -> impl Iterator<Item = PexPeerInfo> + Clone + 'a {
+        let addrs = buf.as_ref().chunks_exact(ip_len + 2).map(move |c| {
+            let ip = match ip_len {
+                4 => IpAddr::from(TryInto::<[u8; 4]>::try_into(&c[..4]).unwrap()),
+                16 => IpAddr::from(TryInto::<[u8; 16]>::try_into(&c[..16]).unwrap()),
+                _ => unreachable!(),
+            };
+            let port = BE::read_u16(&c[ip_len..]);
+            SocketAddr::new(ip, port)
+        });
+        let flags = flags
+            .as_ref()
+            .map(|b| b.as_ref().iter().copied())
+            .into_iter()
+            .flatten();
+        addrs.zip_longest(flags).filter_map(|eob| match eob {
+            EitherOrBoth::Both(addr, flags) => Some(PexPeerInfo { flags, addr }),
+            EitherOrBoth::Left(addr) => Some(PexPeerInfo { flags: 0, addr }),
+            EitherOrBoth::Right(_) => None,
+        })
+    }
+
+    pub fn added_peers(&self) -> impl Iterator<Item = PexPeerInfo> + Clone + '_ {
+        self.added_peers_inner(&self.added, &self.added_f, 4)
+            .chain(self.added_peers_inner(&self.added6, &self.added6_f, 16))
+    }
+
+    pub fn dropped_peers(&self) -> impl Iterator<Item = PexPeerInfo> + Clone + '_ {
+        self.added_peers_inner(&self.dropped, &None, 4)
+            .chain(self.added_peers_inner(&self.dropped6, &None, 16))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use bencode::from_bytes;
+    use buffers::ByteBuf;
+
+    use super::*;
+
+    fn decode_hex(s: &str) -> Vec<u8> {
+        assert!(s.len() % 2 == 0);
+        (0..s.len())
+            .step_by(2)
+            .map(|i| u8::from_str_radix(&s[i..i + 2], 16).unwrap())
+            .collect()
+    }
+
+    #[test]
+    fn test_pex_deserialization() {
+        let msg = "64353a616464656431323ab99f9d14b56797f969861090373a61646465642e66323a0c00363a616464656436303a383a6164646564362e66303a373a64726f70706564303a383a64726f7070656436303a65";
+        let bytes = decode_hex(msg);
+        let pex = from_bytes::<UtPex<ByteBuf>>(&bytes).unwrap();
+        let addrs: Vec<_> = pex.added_peers().collect();
+        assert_eq!(2, addrs.len());
+        assert_eq!(
+            "185.159.157.20:46439".parse::<SocketAddr>().unwrap(),
+            addrs[0].addr
+        );
+        assert_eq!(12, addrs[0].flags);
+        assert_eq!(
+            "151.249.105.134:4240".parse::<SocketAddr>().unwrap(),
+            addrs[1].addr
+        );
+        assert_eq!(0, addrs[1].flags);
+    }
+}
diff --git a/crates/peer_binary_protocol/src/lib.rs b/crates/peer_binary_protocol/src/lib.rs
index bd2d1a8..27926df 100644
--- a/crates/peer_binary_protocol/src/lib.rs
+++ b/crates/peer_binary_protocol/src/lib.rs
@@ -5,10 +5,11 @@
 pub mod extended;
 
 use bincode::Options;
-use buffers::{ByteBuf, ByteBufOwned};
+use buffers::{ByteBuf, ByteBufOwned, ByteBufT};
 use byteorder::{ByteOrder, BE};
 use bytes::Bytes;
 use clone_to_owned::CloneToOwned;
+use extended::PeerExtendedMessageIds;
 use librqbit_core::{constants::CHUNK_SIZE, hash_id::Id20, lengths::ChunkInfo};
 use serde::{Deserialize, Serialize};
 
@@ -47,6 +48,9 @@ const MSGID_EXTENDED: u8 = 20;
 pub const EXTENDED_UT_METADATA_KEY: &[u8] = b"ut_metadata";
 pub const MY_EXTENDED_UT_METADATA: u8 = 3;
 
+pub const EXTENDED_UT_PEX_KEY: &[u8] = b"ut_pex";
+pub const MY_EXTENDED_UT_PEX: u8 = 1;
+
 #[derive(Debug)]
 pub enum MessageDeserializeError {
     NotEnoughData(usize, &'static str),
@@ -182,7 +186,7 @@ impl From<anyhow::Error> for MessageDeserializeError {
 }
 
 #[derive(Debug)]
-pub enum Message<ByteBuf: std::hash::Hash + Eq> {
+pub enum Message<ByteBuf: ByteBufT> {
     Request(Request),
     Cancel(Request),
     Bitfield(ByteBuf),
@@ -208,8 +212,8 @@ pub struct Bitfield<'a> {
 
 impl<ByteBuf> CloneToOwned for Message<ByteBuf>
 where
-    ByteBuf: CloneToOwned + std::hash::Hash + Eq,
-    <ByteBuf as CloneToOwned>::Target: std::hash::Hash + Eq,
+    ByteBuf: ByteBufT,
+    <ByteBuf as CloneToOwned>::Target: ByteBufT,
 {
     type Target = Message<<ByteBuf as CloneToOwned>::Target>;
 
@@ -253,7 +257,7 @@ impl<'a> std::fmt::Debug for Bitfield<'a> {
 
 impl<ByteBuf> Message<ByteBuf>
 where
-    ByteBuf: AsRef<[u8]> + std::hash::Hash + Eq + Serialize,
+    ByteBuf: ByteBufT,
 {
     pub fn len_prefix_and_msg_id(&self) -> (u32, u8) {
         match self {
@@ -276,7 +280,7 @@ where
     pub fn serialize(
         &self,
         out: &mut Vec<u8>,
-        extended_handshake_ut_metadata: &dyn Fn() -> Option<u8>,
+        peer_extended_messages: &dyn Fn() -> PeerExtendedMessageIds,
     ) -> anyhow::Result<usize> {
         let (lp, msg_id) = self.len_prefix_and_msg_id();
 
@@ -326,7 +330,7 @@ where
                 Ok(msg_len)
             }
             Message::Extended(e) => {
-                e.serialize(out, extended_handshake_ut_metadata)?;
+                e.serialize(out, peer_extended_messages)?;
                 let msg_size = out.len();
                 // no fucking idea why +1, but I tweaked that for it all to match up
                 // with real messages.
@@ -636,7 +640,7 @@ mod tests {
     fn test_extended_serialize() {
         let msg = Message::Extended(ExtendedMessage::Handshake(ExtendedHandshake::new()));
         let mut out = Vec::new();
-        msg.serialize(&mut out, &|| None).unwrap();
+        msg.serialize(&mut out, &Default::default).unwrap();
         dbg!(out);
     }
 
@@ -652,7 +656,7 @@ mod tests {
         let (msg, size) = MessageBorrowed::deserialize(&buf).unwrap();
         assert_eq!(size, buf.len());
         let mut write_buf = Vec::new();
-        msg.serialize(&mut write_buf, &|| None).unwrap();
+        msg.serialize(&mut write_buf, &Default::default).unwrap();
         if buf != write_buf {
             {
                 use std::io::Write;
diff --git a/desktop/src-tauri/Cargo.lock b/desktop/src-tauri/Cargo.lock
index 0169880..bdfd740 100644
--- a/desktop/src-tauri/Cargo.lock
+++ b/desktop/src-tauri/Cargo.lock
@@ -68,17 +68,6 @@ version = "1.0.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b3d1d046238990b9cf5bcde22a3fb3584ee5cf65fb2765f454ed428c7a0063da"
 
-[[package]]
-name = "async-recursion"
-version = "1.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b43422f69d8ff38f95f1b2bb76517c91589a924d1559a0e935d7c8ce0274c11"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 2.0.76",
-]
-
 [[package]]
 name = "async-stream"
 version = "0.3.5"
@@ -329,9 +318,9 @@ checksum = "79296716171880943b8470b5f8d03aa55eb2e645a4874bdbb28adb49162e012c"
 
 [[package]]
 name = "bytemuck"
-version = "1.17.0"
+version = "1.17.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6fd4c6dcc3b0aea2f5c0b4b82c2b15fe39ddbc76041a310848f4706edf76bb31"
+checksum = "773d90827bc3feecfb67fab12e24de0749aad83c74b9504ecde46237b5cd24e2"
 
 [[package]]
 name = "byteorder"
@@ -901,9 +890,9 @@ dependencies = [
 
 [[package]]
 name = "filetime"
-version = "0.2.24"
+version = "0.2.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bf401df4a4e3872c4fe8151134cf483738e74b67fc934d6532c882b3d24a4550"
+checksum = "35c0522e981e68cbfa8c3f978441a5f34b30b96e146b33cd3359176b50fe8586"
 dependencies = [
  "cfg-if",
  "libc",
@@ -1842,7 +1831,7 @@ dependencies = [
 
 [[package]]
 name = "librqbit"
-version = "7.0.0-beta.3"
+version = "7.0.0"
 dependencies = [
  "anyhow",
  "async-stream",
@@ -1868,6 +1857,7 @@ dependencies = [
  "librqbit-sha1-wrapper",
  "librqbit-tracker-comms",
  "librqbit-upnp",
+ "librqbit-upnp-serve",
  "memmap2",
  "mime_guess",
  "parking_lot",
@@ -1887,7 +1877,6 @@ dependencies = [
  "tower-http",
  "tracing",
  "tracing-subscriber",
- "upnp-serve",
  "url",
  "urlencoding",
  "uuid",
@@ -1895,7 +1884,7 @@ dependencies = [
 
 [[package]]
 name = "librqbit-bencode"
-version = "3.0.0"
+version = "3.0.1"
 dependencies = [
  "anyhow",
  "bytes",
@@ -1923,7 +1912,7 @@ dependencies = [
 
 [[package]]
 name = "librqbit-core"
-version = "4.0.0"
+version = "4.0.1"
 dependencies = [
  "anyhow",
  "bytes",
@@ -1978,6 +1967,7 @@ dependencies = [
  "bitvec",
  "byteorder",
  "bytes",
+ "itertools",
  "librqbit-bencode",
  "librqbit-buffers",
  "librqbit-clone-to-owned",
@@ -1987,14 +1977,14 @@ dependencies = [
 
 [[package]]
 name = "librqbit-sha1-wrapper"
-version = "3.0.0"
+version = "4.0.0"
 dependencies = [
  "crypto-hash",
 ]
 
 [[package]]
 name = "librqbit-tracker-comms"
-version = "1.0.3"
+version = "2.0.0"
 dependencies = [
  "anyhow",
  "async-stream",
@@ -2017,7 +2007,6 @@ name = "librqbit-upnp"
 version = "0.1.1"
 dependencies = [
  "anyhow",
- "async-recursion",
  "bstr",
  "futures",
  "httparse",
@@ -2030,6 +2019,32 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "librqbit-upnp-serve"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "axum",
+ "bstr",
+ "gethostname",
+ "http 1.1.0",
+ "httparse",
+ "librqbit-core",
+ "librqbit-sha1-wrapper",
+ "librqbit-upnp",
+ "mime_guess",
+ "parking_lot",
+ "quick-xml 0.36.1",
+ "reqwest",
+ "serde",
+ "socket2",
+ "tokio",
+ "tokio-util",
+ "tracing",
+ "url",
+ "uuid",
+]
+
 [[package]]
 name = "linux-raw-sys"
 version = "0.4.14"
@@ -2235,8 +2250,9 @@ dependencies = [
 
 [[package]]
 name = "network-interface"
-version = "1.1.1"
-source = "git+https://github.com/ikatson/network-interface?branch=compile-on-freebsd#aca8a95ab1bb41a27bc82c6a2425eb4824bf0352"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "433419f898328beca4f2c6c73a1b52540658d92b0a99f0269330457e0fd998d5"
 dependencies = [
  "cc",
  "libc",
@@ -2809,6 +2825,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "96a05e2e8efddfa51a84ca47cec303fac86c8541b686d37cac5efc0e094417bc"
 dependencies = [
  "memchr",
+ "serde",
 ]
 
 [[package]]
@@ -3054,18 +3071,18 @@ checksum = "719b953e2095829ee67db738b3bfa9fa368c94900df327b3f07fe6e794d2fe1f"
 
 [[package]]
 name = "rustc_version"
-version = "0.4.0"
+version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bfa0f585226d2e68097d4f95d113b15b83a82e819ab25717ec0590d9584ef366"
+checksum = "cfcb3a22ef46e85b45de6ee7e79d063319ebb6594faafcf1c225ea92ab6e9b92"
 dependencies = [
  "semver",
 ]
 
 [[package]]
 name = "rustix"
-version = "0.38.34"
+version = "0.38.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70dc5ec042f7a43c4a73241207cecc9873a06d45debb38b329f8541d85c2730f"
+checksum = "a85d50532239da68e9addb745ba38ff4612a242c1c7ceea689c4bc7c2f43c36f"
 dependencies = [
  "bitflags 2.6.0",
  "errno",
@@ -4241,31 +4258,6 @@ version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d4c87d22b6e3f4a18d4d40ef354e97c90fcb14dd91d7dc0aa9d8a1172ebf7202"
 
-[[package]]
-name = "upnp-serve"
-version = "0.1.0"
-dependencies = [
- "anyhow",
- "axum",
- "bstr",
- "gethostname",
- "http 1.1.0",
- "httparse",
- "librqbit-core",
- "librqbit-sha1-wrapper",
- "librqbit-upnp",
- "mime_guess",
- "parking_lot",
- "quick-xml 0.36.1",
- "reqwest",
- "socket2",
- "tokio",
- "tokio-util",
- "tracing",
- "url",
- "uuid",
-]
-
 [[package]]
 name = "url"
 version = "2.5.2"