diff --git a/crates/librqbit/src/http_api.rs b/crates/librqbit/src/http_api.rs
index 96c3e20..22e3ba4 100644
--- a/crates/librqbit/src/http_api.rs
+++ b/crates/librqbit/src/http_api.rs
@@ -1,7 +1,7 @@
 use anyhow::Context;
 use dht::{Dht, DhtStats};
 use parking_lot::RwLock;
-use serde::Serialize;
+use serde::{Deserialize, Serialize};
 use std::net::SocketAddr;
 use std::sync::Arc;
 use std::time::{Duration, Instant};
@@ -9,7 +9,7 @@ use warp::hyper::body::Bytes;
 use warp::hyper::Body;
 use warp::Filter;
 
-use crate::session::Session;
+use crate::session::{AddTorrentOptions, Session};
 use crate::torrent_manager::TorrentManagerHandle;
 use crate::torrent_state::StatsSnapshot;
 
@@ -127,10 +127,14 @@ impl ApiInternal {
         Some(TorrentDetailsResponse { info_hash, files })
     }
 
-    async fn api_add_torrent(&self, url: String) -> anyhow::Result<usize> {
+    async fn api_add_torrent(
+        &self,
+        url: String,
+        opts: Option<AddTorrentOptions>,
+    ) -> anyhow::Result<usize> {
         let handle = self
             .session
-            .add_torrent(url, None)
+            .add_torrent(url, opts)
             .await
             .context("error adding torrent")?
             .context("expected session.add_torrent() to return a handle")?;
@@ -258,16 +262,22 @@ impl HttpApi {
             move || json_response(inner.api_torrent_list())
         });
 
+        #[derive(Deserialize)]
+        struct TorrentAddQueryParams {
+            overwrite: Option<bool>,
+        }
+
         let torrent_add = warp::post()
             .and(warp::path("torrents"))
             .and(warp::body::bytes())
+            .and(warp::query())
             .and_then({
                 let inner = inner.clone();
                 use warp::http::Response;
                 fn make_response(status: u16, body: String) -> Response<String> {
                     Response::builder().status(status).body(body).unwrap()
                 }
-                move |body: Bytes| {
+                move |body: Bytes, params: TorrentAddQueryParams| {
                     let inner = inner.clone();
                     async move {
                         let url = match String::from_utf8(body.to_vec()) {
@@ -279,8 +289,12 @@ impl HttpApi {
                                 ))
                             }
                         };
+                        let opts = AddTorrentOptions {
+                            overwrite: params.overwrite.unwrap_or(false),
+                            ..Default::default()
+                        };
                         let idx = inner
-                            .api_add_torrent(url)
+                            .api_add_torrent(url, Some(opts))
                             .await
                             .context("error calling HttpApi::api_add_torrent");
                         match idx {
diff --git a/crates/librqbit/src/session.rs b/crates/librqbit/src/session.rs
index f34a14f..001917e 100644
--- a/crates/librqbit/src/session.rs
+++ b/crates/librqbit/src/session.rs
@@ -9,6 +9,7 @@ use librqbit_core::{
     torrent_metainfo::{torrent_from_bytes, TorrentMetaV1Info, TorrentMetaV1Owned},
 };
 use log::{info, warn};
+use parking_lot::RwLock;
 use reqwest::Url;
 use tokio_stream::StreamExt;
 
@@ -21,11 +22,45 @@ use crate::{
     torrent_manager::{TorrentManagerBuilder, TorrentManagerHandle},
 };
 
+pub enum ManagedTorrentState {
+    Initializing,
+    Running(TorrentManagerHandle),
+}
+
+pub struct ManagedTorrent {
+    info_hash: Id20,
+    output_folder: PathBuf,
+    state: ManagedTorrentState,
+}
+
+impl PartialEq for ManagedTorrent {
+    fn eq(&self, other: &Self) -> bool {
+        self.info_hash == other.info_hash && self.output_folder == other.output_folder
+    }
+}
+
+#[derive(Default)]
+pub struct SessionLocked {
+    torrents: Vec<ManagedTorrent>,
+}
+
+impl SessionLocked {
+    fn add_torrent(&mut self, torrent: ManagedTorrent) -> Option<usize> {
+        if self.torrents.contains(&torrent) {
+            return None;
+        }
+        let idx = self.torrents.len();
+        self.torrents.push(torrent);
+        Some(idx)
+    }
+}
+
 pub struct Session {
     peer_id: Id20,
     dht: Option<Dht>,
     peer_opts: PeerConnectionOptions,
     spawner: BlockingSpawner,
+    locked: RwLock<SessionLocked>,
     output_folder: PathBuf,
 }
 
@@ -126,6 +161,7 @@ impl Session {
             peer_opts,
             spawner,
             output_folder,
+            locked: RwLock::new(SessionLocked::default()),
         })
     }
     pub fn get_dht(&self) -> Option<Dht> {
@@ -271,7 +307,21 @@ impl Session {
             .map(PathBuf::from)
             .unwrap_or_else(|| self.output_folder.clone());
 
-        let mut builder = TorrentManagerBuilder::new(info, info_hash, output_folder);
+        let managed_torrent = ManagedTorrent {
+            info_hash,
+            output_folder: output_folder.clone(),
+            state: ManagedTorrentState::Initializing,
+        };
+
+        if self.locked.write().add_torrent(managed_torrent).is_none() {
+            anyhow::bail!(
+                "torrent with info_hash {:?} that is downloaded to {:?} is already managed",
+                info_hash,
+                &output_folder
+            );
+        };
+
+        let mut builder = TorrentManagerBuilder::new(info, info_hash, output_folder.clone());
         builder
             .overwrite(opts.overwrite)
             .spawner(self.spawner)
@@ -287,7 +337,40 @@ impl Session {
             builder.peer_connect_timeout(t);
         }
 
-        let handle = builder.start_manager()?;
+        let handle = match builder
+            .start_manager()
+            .context("error starting torrent manager")
+        {
+            Ok(handle) => {
+                let mut g = self.locked.write();
+                let m = g
+                    .torrents
+                    .iter_mut()
+                    .find(|t| t.info_hash == info_hash && t.output_folder == output_folder)
+                    .unwrap();
+                m.state = ManagedTorrentState::Running(handle.clone());
+                handle
+            }
+            Err(error) => {
+                let mut g = self.locked.write();
+                let idx = g
+                    .torrents
+                    .iter()
+                    .position(|t| t.info_hash == info_hash && t.output_folder == output_folder)
+                    .unwrap();
+                g.torrents.remove(idx);
+                return Err(error);
+            }
+        };
+        {
+            let mut g = self.locked.write();
+            let m = g
+                .torrents
+                .iter_mut()
+                .find(|t| t.info_hash == info_hash && t.output_folder == output_folder)
+                .unwrap();
+            m.state = ManagedTorrentState::Running(handle.clone());
+        }
 
         for url in trackers {
             handle.add_tracker(url);