diff --git a/soulseek-rs-lib/src/client/mod.rs b/soulseek-rs-lib/src/client/mod.rs
index cbfb62b..dd71552 100644
--- a/soulseek-rs-lib/src/client/mod.rs
+++ b/soulseek-rs-lib/src/client/mod.rs
@@ -59,6 +59,18 @@ fn next_upload_token() -> u32 {
 struct UploadJob {
     downloader: String,
     real_path: std::path::PathBuf,
+    virtual_path: String,
+    size: u64,
+}
+
+/// Live bookkeeping for an upload being served (or recently finished).
+struct ActiveUpload {
+    username: String,
+    filename: String,
+    size: u64,
+    bytes_sent: Arc<std::sync::atomic::AtomicU64>,
+    cancel: Arc<std::sync::atomic::AtomicBool>,
+    status: crate::types::UploadStatus,
 }
 
 /// Build a `FileSearchResponse` for `query` against `shares`, or `None` if
@@ -210,6 +222,7 @@ pub struct ClientContext {
     pending_peer_messages: HashMap<String, Vec<crate::message::Message>>,
     /// Uploads we have offered, keyed by our transfer token.
     uploads: HashMap<u32, UploadJob>,
+    active_uploads: HashMap<u32, ActiveUpload>,
     /// Upload tokens waiting for the downloader's address to be resolved.
     pending_serves: HashMap<String, Vec<u32>>,
     /// Shared-file listings received from peers we browsed.
@@ -507,6 +520,7 @@ impl ClientContext {
             peer_addresses: HashMap::new(),
             pending_peer_messages: HashMap::new(),
             uploads: HashMap::new(),
+            active_uploads: HashMap::new(),
             pending_serves: HashMap::new(),
             browse_results: HashMap::new(),
             room_list: Vec::new(),
@@ -657,6 +671,54 @@ impl Client {
             .unwrap_or_default()
     }
 
+    /// Snapshot of the uploads served this session (active and finished),
+    /// most recent last.
+    #[must_use]
+    pub fn uploads(&self) -> Vec<crate::types::UploadInfo> {
+        self.context.read_safe().map_or_else(
+            |_| Vec::new(),
+            |ctx| {
+                let mut tokens: Vec<&u32> = ctx.active_uploads.keys().collect();
+                tokens.sort_unstable();
+                tokens
+                    .into_iter()
+                    .map(|token| {
+                        let upload = &ctx.active_uploads[token];
+                        crate::types::UploadInfo {
+                            username: upload.username.clone(),
+                            filename: upload.filename.clone(),
+                            size: upload.size,
+                            bytes_sent: upload
+                                .bytes_sent
+                                .load(std::sync::atomic::Ordering::Relaxed),
+                            status: upload.status.clone(),
+                        }
+                    })
+                    .collect()
+            },
+        )
+    }
+
+    /// Ask an in-progress upload to `username` of `filename` to stop.
+    /// Returns whether a matching in-progress upload was found.
+    pub fn cancel_upload(&self, username: &str, filename: &str) -> bool {
+        self.context.read_safe().is_ok_and(|ctx| {
+            let mut found = false;
+            for upload in ctx.active_uploads.values() {
+                if upload.username == username
+                    && upload.filename == filename
+                    && upload.status == crate::types::UploadStatus::InProgress
+                {
+                    upload
+                        .cancel
+                        .store(true, std::sync::atomic::Ordering::Relaxed);
+                    found = true;
+                }
+            }
+            found
+        })
+    }
+
     /// Replace the shared directories at runtime: rescan into a fresh
     /// index (served to peers from then on) and re-announce the new
     /// folder/file counts to the server.
diff --git a/soulseek-rs-lib/src/client/operations.rs b/soulseek-rs-lib/src/client/operations.rs
index 6919e8c..38d820e 100644
--- a/soulseek-rs-lib/src/client/operations.rs
+++ b/soulseek-rs-lib/src/client/operations.rs
@@ -652,6 +652,8 @@ impl Client {
                                             UploadJob {
                                                 downloader: downloader.clone(),
                                                 real_path,
+                                                virtual_path: filename.clone(),
+                                                size,
                                             },
                                         );
                                         (ctx.peer_registry.clone(), size)
diff --git a/soulseek-rs-lib/src/client/uploads.rs b/soulseek-rs-lib/src/client/uploads.rs
index 5aa65f2..e395318 100644
--- a/soulseek-rs-lib/src/client/uploads.rs
+++ b/soulseek-rs-lib/src/client/uploads.rs
@@ -1,7 +1,9 @@
 use super::{
-    Arc, Client, ClientContext, DownloadStatus, RwLock, RwLockExt,
-    collect_failed_tokens, error, thread,
+    ActiveUpload, Arc, Client, ClientContext, DownloadStatus, RwLock,
+    RwLockExt, collect_failed_tokens, error, thread,
 };
+use crate::types::UploadStatus;
+use std::sync::atomic::{AtomicBool, AtomicU64};
 
 impl Client {
     /// Consume the upload job for `token` and stream the file to `host:port`
@@ -19,14 +21,47 @@ impl Client {
         let Some(job) = ctx.uploads.remove(&token) else {
             return;
         };
+        let bytes_sent = Arc::new(AtomicU64::new(0));
+        let cancel = Arc::new(AtomicBool::new(false));
+        ctx.active_uploads.insert(
+            token,
+            ActiveUpload {
+                username: job.downloader.clone(),
+                filename: job.virtual_path.clone(),
+                size: job.size,
+                bytes_sent: bytes_sent.clone(),
+                cancel: cancel.clone(),
+                status: UploadStatus::InProgress,
+            },
+        );
         drop(ctx);
         let own = own_username.to_string();
         let real_path = job.real_path;
+        let context = client_context.clone();
         thread::spawn(move || {
-            if let Err(e) = crate::peer::upload_peer::serve_file(
-                &host, port, &own, token, &real_path,
-            ) {
-                error!("[client] serve {}: {}", real_path.display(), e);
+            let result = crate::peer::upload_peer::serve_file(
+                &host,
+                port,
+                &own,
+                token,
+                &real_path,
+                &bytes_sent,
+                &cancel,
+            );
+            let status = match &result {
+                Ok(()) => UploadStatus::Completed,
+                Err(e) if e.kind() == std::io::ErrorKind::Interrupted => {
+                    UploadStatus::Cancelled
+                }
+                Err(e) => {
+                    error!("[client] serve {}: {}", real_path.display(), e);
+                    UploadStatus::Failed(e.to_string())
+                }
+            };
+            if let Ok(mut ctx) = context.write_safe()
+                && let Some(upload) = ctx.active_uploads.get_mut(&token)
+            {
+                upload.status = status;
             }
         });
     }
diff --git a/soulseek-rs-lib/src/peer/upload_peer.rs b/soulseek-rs-lib/src/peer/upload_peer.rs
index b0aecd3..30786a0 100644
--- a/soulseek-rs-lib/src/peer/upload_peer.rs
+++ b/soulseek-rs-lib/src/peer/upload_peer.rs
@@ -4,6 +4,7 @@ use std::fs::File;
 use std::io::{self, Read, Write};
 use std::net::{TcpStream, ToSocketAddrs};
 use std::path::Path;
+use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
 use std::time::Duration;
 
 use crate::message::server::MessageFactory;
@@ -17,6 +18,9 @@ use crate::trace;
 /// download is matched by token), then the downloader sends an 8-byte
 /// START_DOWNLOAD offset before we stream the file.
 ///
+/// `bytes_sent` is updated as the transfer progresses, and setting `cancel`
+/// aborts the stream with an [`io::ErrorKind::Interrupted`] error.
+///
 /// # Errors
 /// Returns any I/O error opening the file or talking to the peer.
 pub fn serve_file(
@@ -25,6 +29,8 @@ pub fn serve_file(
     own_username: &str,
     token: u32,
     path: &Path,
+    bytes_sent: &AtomicU64,
+    cancel: &AtomicBool,
 ) -> io::Result<()> {
     let mut file = File::open(path)?;
 
@@ -53,7 +59,21 @@ pub fn serve_file(
     let mut offset = [0u8; 8];
     stream.read_exact(&mut offset)?;
 
-    io::copy(&mut file, &mut stream)?;
+    let mut buffer = [0u8; 64 * 1024];
+    loop {
+        if cancel.load(Ordering::Relaxed) {
+            return Err(io::Error::new(
+                io::ErrorKind::Interrupted,
+                "upload cancelled",
+            ));
+        }
+        let read = file.read(&mut buffer)?;
+        if read == 0 {
+            break;
+        }
+        stream.write_all(&buffer[..read])?;
+        bytes_sent.fetch_add(read as u64, Ordering::Relaxed);
+    }
     stream.flush()?;
 
     // Linger so the downloader drains everything before the socket closes.
@@ -67,6 +87,8 @@ mod tests {
     use super::serve_file;
     use std::io::{Read, Write};
     use std::net::TcpListener;
+    use std::sync::Arc;
+    use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
 
     #[test]
     fn serve_file_streams_the_file_over_an_f_connection() {
@@ -80,8 +102,18 @@ mod tests {
         let listener = TcpListener::bind("127.0.0.1:0").unwrap();
         let port = u32::from(listener.local_addr().unwrap().port());
 
+        let bytes_sent = Arc::new(AtomicU64::new(0));
+        let sent_counter = bytes_sent.clone();
         let uploader = std::thread::spawn(move || {
-            serve_file("127.0.0.1", port, "me", 777, &path)
+            serve_file(
+                "127.0.0.1",
+                port,
+                "me",
+                777,
+                &path,
+                &sent_counter,
+                &AtomicBool::new(false),
+            )
         });
 
         // Downloader side: accept, read PeerInit(F) frame + raw token, send the
@@ -104,6 +136,53 @@ mod tests {
         assert_eq!(received, content);
 
         let _ = uploader.join();
+        assert_eq!(bytes_sent.load(Ordering::Relaxed), 4096);
+        let _ = std::fs::remove_dir_all(dir);
+    }
+
+    #[test]
+    fn serve_file_stops_when_cancelled() {
+        let dir = std::env::temp_dir()
+            .join(format!("soulseek-upload-cancel-{}", std::process::id()));
+        std::fs::create_dir_all(&dir).unwrap();
+        let path = dir.join("big.bin");
+        std::fs::write(&path, vec![7u8; 1024 * 1024]).unwrap();
+
+        let listener = TcpListener::bind("127.0.0.1:0").unwrap();
+        let port = u32::from(listener.local_addr().unwrap().port());
+
+        // Cancelled before the copy loop starts: the stream must abort with
+        // Interrupted instead of serving the whole file.
+        let cancel = Arc::new(AtomicBool::new(true));
+        let cancel_flag = cancel.clone();
+        let uploader = std::thread::spawn(move || {
+            serve_file(
+                "127.0.0.1",
+                port,
+                "me",
+                778,
+                &path,
+                &AtomicU64::new(0),
+                &cancel_flag,
+            )
+        });
+
+        let (mut stream, _) = listener.accept().unwrap();
+        let mut len_buf = [0u8; 4];
+        stream.read_exact(&mut len_buf).unwrap();
+        let mut payload = vec![0u8; u32::from_le_bytes(len_buf) as usize];
+        stream.read_exact(&mut payload).unwrap();
+        let mut token = [0u8; 4];
+        stream.read_exact(&mut token).unwrap();
+        stream.write_all(&[0u8; 8]).unwrap();
+        stream.flush().unwrap();
+
+        let mut received = Vec::new();
+        let _ = stream.read_to_end(&mut received);
+        assert!(received.is_empty(), "no file bytes after cancellation");
+
+        let err = uploader.join().unwrap().unwrap_err();
+        assert_eq!(err.kind(), std::io::ErrorKind::Interrupted);
         let _ = std::fs::remove_dir_all(dir);
     }
 }
diff --git a/soulseek-rs-lib/src/types.rs b/soulseek-rs-lib/src/types.rs
index a22486f..6c50854 100644
--- a/soulseek-rs-lib/src/types.rs
+++ b/soulseek-rs-lib/src/types.rs
@@ -251,3 +251,24 @@ mod tests {
         assert_eq!(transfer.size, 0);
     }
 }
+
+/// Lifecycle of a file we are serving to a peer.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum UploadStatus {
+    InProgress,
+    Completed,
+    Cancelled,
+    Failed(String),
+}
+
+/// A snapshot of one upload for display purposes.
+#[derive(Debug, Clone)]
+pub struct UploadInfo {
+    /// The peer receiving the file.
+    pub username: String,
+    /// The peer-facing virtual path being served.
+    pub filename: String,
+    pub size: u64,
+    pub bytes_sent: u64,
+    pub status: UploadStatus,
+}
diff --git a/soulseek-rs-lib/tests/e2e.rs b/soulseek-rs-lib/tests/e2e.rs
index 10bea24..a1ccbc5 100644
--- a/soulseek-rs-lib/tests/e2e.rs
+++ b/soulseek-rs-lib/tests/e2e.rs
@@ -1245,6 +1245,24 @@ fn two_real_clients_search_and_download() {
         .expect("downloaded file should exist");
     assert_eq!(written, content, "downloaded bytes should match the source");
 
+    // The uploader side tracked the transfer and saw it complete.
+    let deadline = Instant::now() + Duration::from_secs(5);
+    let mut uploads = sharer.uploads();
+    while Instant::now() < deadline
+        && !uploads
+            .iter()
+            .any(|u| u.status == soulseek_rs::types::UploadStatus::Completed)
+    {
+        std::thread::sleep(Duration::from_millis(200));
+        uploads = sharer.uploads();
+    }
+    let upload = uploads
+        .iter()
+        .find(|u| u.status == soulseek_rs::types::UploadStatus::Completed)
+        .expect("uploader should record a completed upload");
+    assert_eq!(upload.username, "e2e_leecher");
+    assert_eq!(upload.bytes_sent, size);
+
     let _ = std::fs::remove_dir_all(share_dir);
     let _ = std::fs::remove_dir_all(download_dir);
 }