diff --git a/README.md b/README.md
index 14a952f..ab42396 100644
--- a/README.md
+++ b/README.md
@@ -61,6 +61,10 @@ docker-compose logs -f mytube
 
 ### Available variables
 
+You can also load variables from files:
+* Docker CLI supports `--env-file /path/to/.env`.
+* The container entrypoint auto-loads `/app/.env` if present, and also loads a custom file when `ENV_FILE` points to it.
+
 ### ⬇️ Download Behavior
 
 * __MAX_CONCURRENT_DOWNLOADS__: Max simultaneous downloads. Defaults to `3`. 
diff --git a/app/main.py b/app/main.py
index 6a17bc2..18335c6 100644
--- a/app/main.py
+++ b/app/main.py
@@ -448,40 +448,50 @@ def _migrate_legacy_request(post: dict) -> dict:
 
 public_visit_downloads: dict[str, set[str]] = {}
 public_download_owner: dict[str, str] = {}
+public_download_owner_by_key: dict[str, str] = {}
 public_download_owner_by_id: dict[str, str] = {}
 public_visit_sids: dict[str, set[str]] = {}
 public_sid_visit: dict[str, str] = {}
 
 
-def _register_public_download(visit_id: str, url: str):
-    if not visit_id or not url:
+def _register_public_download(visit_id: str, owner_key: str):
+    if not visit_id or not owner_key:
         return
-    public_visit_downloads.setdefault(visit_id, set()).add(url)
-    public_download_owner[url] = visit_id
+    public_visit_downloads.setdefault(visit_id, set()).add(owner_key)
+    public_download_owner[owner_key] = visit_id
 
 
-def _forget_public_download(url: str | None = None, *, dl_id: str | None = None):
+def _forget_public_download(owner_key: str | None = None, *, dl_id: str | None = None):
     visit_id = None
+    keys_to_remove = set()
     if dl_id:
         visit_id = public_download_owner_by_id.pop(dl_id, None)
-    if visit_id is None and url:
-        visit_id = public_download_owner.pop(url, None)
+        keys_to_remove.add(dl_id)
+    if owner_key:
+        visit_id = visit_id or public_download_owner_by_key.pop(owner_key, None)
+        keys_to_remove.add(owner_key)
+    if owner_key and visit_id is None:
+        visit_id = public_download_owner.pop(owner_key, None)
+    if visit_id is None:
+        for key in list(keys_to_remove):
+            owner = public_download_owner.pop(key, None)
+            visit_id = visit_id or owner
     if not visit_id:
         return
-    urls = public_visit_downloads.get(visit_id)
-    if not urls:
+    owned = public_visit_downloads.get(visit_id)
+    if not owned:
         return
-    if url:
-        urls.discard(url)
-    if not urls:
+    for key in keys_to_remove:
+        owned.discard(key)
+    if not owned:
         public_visit_downloads.pop(visit_id, None)
 
 
-async def _emit_download_event(event: str, payload, *, url: str | None = None, dl_id: str | None = None):
+async def _emit_download_event(event: str, payload, *, owner_key: str | None = None, url: str | None = None, dl_id: str | None = None):
     if not config.PUBLIC_MODE:
         await sio.emit(event, payload)
         return
-    visit_id = (public_download_owner_by_id.get(dl_id) if dl_id else None) or (public_download_owner.get(url) if url else None)
+    visit_id = (public_download_owner_by_id.get(dl_id) if dl_id else None) or (public_download_owner_by_key.get(owner_key) if owner_key else None) or (public_download_owner.get(owner_key) if owner_key else None) or (public_download_owner.get(url) if url else None)
     if not visit_id:
         return
     for sid in list(public_visit_sids.get(visit_id, set())):
@@ -497,27 +507,35 @@ class Notifier(DownloadQueueNotifier):
     async def added(self, dl):
         log.info(f"Notifier: Download added - {dl.title}")
         visit_id = public_download_owner.get(dl.url)
+        owner_key = getattr(dl, 'key', None)
+        if visit_id and owner_key:
+            public_download_owner_by_key[owner_key] = visit_id
+            public_download_owner[owner_key] = visit_id
+            public_visit_downloads.setdefault(visit_id, set()).add(owner_key)
         if visit_id:
             public_download_owner_by_id[dl.id] = visit_id
-        await _emit_download_event('added', serializer.encode(dl), url=dl.url, dl_id=dl.id)
+            public_download_owner[dl.id] = visit_id
+            public_visit_downloads.setdefault(visit_id, set()).add(dl.id)
+        await _emit_download_event('added', serializer.encode(dl), owner_key=owner_key, url=dl.url, dl_id=dl.id)
 
     async def updated(self, dl):
         log.debug(f"Notifier: Download updated - {dl.title}")
-        await _emit_download_event('updated', serializer.encode(dl), url=dl.url, dl_id=dl.id)
+        await _emit_download_event('updated', serializer.encode(dl), owner_key=getattr(dl, 'key', None), url=dl.url, dl_id=dl.id)
 
     async def completed(self, dl):
         log.info(f"Notifier: Download completed - {dl.title}")
-        await _emit_download_event('completed', serializer.encode(dl), url=dl.url, dl_id=dl.id)
-        _forget_public_download(dl.url, dl_id=dl.id)
+        owner_key = getattr(dl, 'key', None)
+        await _emit_download_event('completed', serializer.encode(dl), owner_key=owner_key, url=dl.url, dl_id=dl.id)
+        _forget_public_download(owner_key or dl.url, dl_id=dl.id)
 
     async def canceled(self, id):
         log.info(f"Notifier: Download canceled - {id}")
-        await _emit_download_event('canceled', serializer.encode(id), url=id, dl_id=id)
+        await _emit_download_event('canceled', serializer.encode(id), owner_key=id, url=id, dl_id=id)
         _forget_public_download(id, dl_id=id)
 
     async def cleared(self, id):
         log.info(f"Notifier: Download cleared - {id}")
-        await _emit_download_event('cleared', serializer.encode(id), url=id, dl_id=id)
+        await _emit_download_event('cleared', serializer.encode(id), owner_key=id, url=id, dl_id=id)
 
 dqueue = DownloadQueue(config, Notifier())
 app.on_startup.append(lambda app: dqueue.initialize())
@@ -1055,8 +1073,9 @@ async def disconnect(sid):
         return
     public_visit_sids.pop(visit_id, None)
     owned = list(public_visit_downloads.pop(visit_id, set()))
-    for url in owned:
-        public_download_owner.pop(url, None)
+    for key in owned:
+        public_download_owner.pop(key, None)
+        public_download_owner_by_key.pop(key, None)
     # remove any lingering id ownership for this visit
     for dl_id, owner in list(public_download_owner_by_id.items()):
         if owner == visit_id:
diff --git a/ui/src/app/services/downloads.service.ts b/ui/src/app/services/downloads.service.ts
index fc48e4f..59a8d8f 100644
--- a/ui/src/app/services/downloads.service.ts
+++ b/ui/src/app/services/downloads.service.ts
@@ -1,5 +1,5 @@
 import { inject, Injectable } from '@angular/core';
-import { HttpClient, HttpErrorResponse } from '@angular/common/http';
+import { HttpClient, HttpErrorResponse, HttpHeaders } from '@angular/common/http';
 import { of, Subject } from 'rxjs';
 import { catchError } from 'rxjs/operators';
 import { MeTubeSocket } from './metube-socket.service';
@@ -135,7 +135,7 @@ export class DownloadsService {
       : (typeof error.error === 'string'
           ? error.error
           : (error.error?.msg || error.message || 'Request failed'));
-    return of({ status: 'error', msg });
+    return of<Status>({ status: 'error', msg });
   }
 
   public add(payload: AddDownloadPayload) {
@@ -160,9 +160,10 @@ export class DownloadsService {
     const ce = payload.clipEnd?.trim();
     if (cs) body['clip_start'] = cs;
     if (ce) body['clip_end'] = ce;
-    const headers = { 'X-Visit-Id': this.socket.getVisitId() };
+    const visitId = typeof this.socket.getVisitId === 'function' ? this.socket.getVisitId() : '';
+    const headers = visitId ? new HttpHeaders({ 'X-Visit-Id': visitId }) : undefined;
     return this.http.post<Status>('add', body, { headers }).pipe(
-      catchError(this.handleHTTPError)
+      catchError((error: HttpErrorResponse) => this.handleHTTPError(error))
     );
   }