feat(clients): separate audiobook download directory for torrent clients (#1500)

## Summary

Related to #1048 (covers the "separate book and audiobook locations"
request, not per-category routing).

Every download client already had a separate audiobook label/category,
but the four torrent clients only had a single save directory, so books
and audiobooks ended up mixed in the client's download folder.

Each torrent client (qBittorrent, Transmission, Deluge, rTorrent) gets
an opt-in **Separate Book and Audiobook Directories** toggle
(`<CLIENT>_SEPARATE_DOWNLOAD_DIRS`, default off):

- **Off (default):** unchanged. The single `<CLIENT>_DOWNLOAD_DIR` is
used for everything, so existing setups behave exactly as before.
- **On:** `<CLIENT>_DOWNLOAD_DIR_BOOK` and
`<CLIENT>_DOWNLOAD_DIR_AUDIOBOOK` replace the shared field. A directory
left empty means the client's own default; it never falls back to the
shared directory or another Shelfmark setting.

The content type was already passed to each client's `add_download`, so
a small shared helper (`resolve_download_dir`) does the selection.

Usenet clients are unchanged: their save location comes from the
category configured in the client, and a separate audiobook category is
already sent.

## Screenshots

Default Setting
<img width="817" height="271" alt="Screenshot 2026-10-20 at 14-54-26
Shelfmark"
src="https://github.com/user-attachments/assets/29941f83-9034-4ea5-bcb2-8e91ce77e63a"
/>

Separate Locations
<img width="817" height="425" alt="Screenshot 2026-10-20 at 14-54-58
Shelfmark"
src="https://github.com/user-attachments/assets/772b7194-a072-4945-bac5-b6959550fd75"
/>


## Not included

Routing to many folders by document type (the main request in #1048)
still only exists for Direct download via Content-Type Routing.
Extending it to torrent and usenet sources needs a decision on what to
route by.

## Testing

- `pytest tests --ignore=tests/e2e` passes (3561 passed); ruff clean.
The `tests/e2e/platform` suite needs a running cluster and was not run.
- New unit tests for the helper (including no fallback to the shared
directory) and a qBittorrent add test covering book vs audiobook
directories.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Sonnet 5.5 <noreply@anthropic.com>

docs/environment-variables.md

@@ -1884,24 +1884,36 @@ How long to keep cached search results before they expire.
 | `DEBRIDLINK_API_KEY` | Debrid-Link API Key from your Debrid-Link account settings | string (secret) | _none_ |
 | `REALDEBRID_API_KEY` | Real-Debrid API Key (Secret Token) from your Real-Debrid account settings | string (secret) | _none_ |
 | `TORBOX_API_KEY` | TorBox API Key from your TorBox account settings | string (secret) | _none_ |
+| `QBITTORRENT_DOWNLOAD_DIR_BOOK` | Server-side directory where book torrents are downloaded (optional, uses qBittorrent default if not specified) | string | _none_ |
+| `QBITTORRENT_DOWNLOAD_DIR_AUDIOBOOK` | Server-side directory where audiobook torrents are downloaded (optional, uses qBittorrent default if not specified) | string | _none_ |
 | `QBITTORRENT_URL` | Web UI URL of your qBittorrent instance | string | _none_ |
 | `QBITTORRENT_USERNAME` | qBittorrent Web UI username | string | _none_ |
 | `QBITTORRENT_PASSWORD` | qBittorrent Web UI password | string (secret) | _none_ |
 | `QBITTORRENT_API_KEY` | Found in qBittorrent: Options > Web UI > API Key (qBittorrent 5.2.0+). Used instead of the username and password when set. | string (secret) | _none_ |
 | `QBITTORRENT_CATEGORY` | Category to assign to book downloads in qBittorrent | string | `books` |
 | `QBITTORRENT_CATEGORY_AUDIOBOOK` | Category for audiobook downloads. Leave empty to use the book category. | string | _empty string_ |
+| `TRANSMISSION_SEPARATE_DOWNLOAD_DIRS` | Download books and audiobooks to different directories instead of one shared directory. | boolean | `false` |
+| `QBITTORRENT_SEPARATE_DOWNLOAD_DIRS` | Download books and audiobooks to different directories instead of one shared directory. | boolean | `false` |
+| `TRANSMISSION_DOWNLOAD_DIR_BOOK` | Server-side directory where book torrents are downloaded (optional, uses Transmission default if not specified) | string | _none_ |
+| `TRANSMISSION_DOWNLOAD_DIR_AUDIOBOOK` | Server-side directory where audiobook torrents are downloaded (optional, uses Transmission default if not specified) | string | _none_ |
 | `QBITTORRENT_DOWNLOAD_DIR` | Server-side directory where torrents are downloaded (optional, uses qBittorrent default if not specified) | string | _none_ |
 | `QBITTORRENT_TAG` | Tag(s) to assign to qBittorrent downloads. Leave empty for no tags. | string (comma-separated) | _empty list_ |
 | `TRANSMISSION_URL` | URL of your Transmission instance (use https:// for TLS) | string | _none_ |
 | `TRANSMISSION_USERNAME` | Transmission RPC username (if authentication enabled) | string | _none_ |
 | `TRANSMISSION_PASSWORD` | Transmission RPC password | string (secret) | _none_ |
+| `DELUGE_SEPARATE_DOWNLOAD_DIRS` | Download books and audiobooks to different directories instead of one shared directory. | boolean | `false` |
 | `TRANSMISSION_CATEGORY` | Label to assign to book downloads in Transmission | string | `books` |
+| `DELUGE_DOWNLOAD_DIR_BOOK` | Server-side directory where book torrents are downloaded (optional, uses Deluge default if not specified) | string | _none_ |
+| `DELUGE_DOWNLOAD_DIR_AUDIOBOOK` | Server-side directory where audiobook torrents are downloaded (optional, uses Deluge default if not specified) | string | _none_ |
 | `TRANSMISSION_CATEGORY_AUDIOBOOK` | Label for audiobook downloads. Leave empty to use the book label. | string | _empty string_ |
 | `TRANSMISSION_DOWNLOAD_DIR` | Server-side directory where torrents are downloaded (optional, uses Transmission default if not specified) | string | _none_ |
 | `DELUGE_HOST` | Hostname/IP or full URL of your Deluge Web UI (deluge-web) | string | `localhost` |
 | `DELUGE_PORT` | Deluge Web UI port (default: 8112) | string | `8112` |
 | `DELUGE_PASSWORD` | Deluge Web UI password (default: deluge) | string (secret) | _none_ |
+| `RTORRENT_SEPARATE_DOWNLOAD_DIRS` | Download books and audiobooks to different directories instead of one shared directory. | boolean | `false` |
 | `DELUGE_CATEGORY` | Label to assign to book downloads in Deluge | string | `books` |
+| `RTORRENT_DOWNLOAD_DIR_BOOK` | Server-side directory where book torrents are downloaded (optional, uses rTorrent default if not specified) | string | _none_ |
+| `RTORRENT_DOWNLOAD_DIR_AUDIOBOOK` | Server-side directory where audiobook torrents are downloaded (optional, uses rTorrent default if not specified) | string | _none_ |
 | `DELUGE_CATEGORY_AUDIOBOOK` | Label for audiobook downloads. Leave empty to use the book label. | string | _empty string_ |
 | `DELUGE_DOWNLOAD_DIR` | Server-side directory where torrents are downloaded (optional, uses Deluge default if not specified) | string | _none_ |
 | `RTORRENT_URL` | XML-RPC URL of your rTorrent instance | string | _none_ |
@@ -2031,6 +2043,15 @@ Category to assign to book downloads in qBittorrent
 - **Default:** `books`
 
 #### `QBITTORRENT_CATEGORY_AUDIOBOOK`
+#### `QBITTORRENT_SEPARATE_DOWNLOAD_DIRS`
+
+**Separate Book and Audiobook Directories**
+
+Download books and audiobooks to different directories instead of one shared directory.
+
+- **Type:** boolean
+- **Default:** `false`
+
 
 **Audiobook Category**
 
@@ -2040,6 +2061,7 @@ Category for audiobook downloads. Leave empty to use the book category.
 - **Default:** _empty string_
 
 #### `QBITTORRENT_DOWNLOAD_DIR`
+#### `QBITTORRENT_DOWNLOAD_DIR_BOOK`
 
 **Download Directory**
 
@@ -2048,6 +2070,23 @@ Server-side directory where torrents are downloaded (optional, uses qBittorrent
 - **Type:** string
 - **Default:** _none_
 
+
+**Book Download Directory**
+
+Server-side directory where book torrents are downloaded (optional, uses qBittorrent default if not specified)
+
+- **Type:** string
+- **Default:** _none_
+
+#### `QBITTORRENT_DOWNLOAD_DIR_AUDIOBOOK`
+
+**Audiobook Download Directory**
+
+Server-side directory where audiobook torrents are downloaded (optional, uses qBittorrent default if not specified)
+
+- **Type:** string
+- **Default:** _none_
+
 #### `QBITTORRENT_TAG`
 
 **Tags**
@@ -2094,6 +2133,15 @@ Label to assign to book downloads in Transmission
 - **Default:** `books`
 
 #### `TRANSMISSION_CATEGORY_AUDIOBOOK`
+#### `TRANSMISSION_SEPARATE_DOWNLOAD_DIRS`
+
+**Separate Book and Audiobook Directories**
+
+Download books and audiobooks to different directories instead of one shared directory.
+
+- **Type:** boolean
+- **Default:** `false`
+
 
 **Audiobook Label**
 
@@ -2103,6 +2151,7 @@ Label for audiobook downloads. Leave empty to use the book label.
 - **Default:** _empty string_
 
 #### `TRANSMISSION_DOWNLOAD_DIR`
+#### `TRANSMISSION_DOWNLOAD_DIR_BOOK`
 
 **Download Directory**
 
@@ -2111,6 +2160,23 @@ Server-side directory where torrents are downloaded (optional, uses Transmission
 - **Type:** string
 - **Default:** _none_
 
+
+**Book Download Directory**
+
+Server-side directory where book torrents are downloaded (optional, uses Transmission default if not specified)
+
+- **Type:** string
+- **Default:** _none_
+
+#### `TRANSMISSION_DOWNLOAD_DIR_AUDIOBOOK`
+
+**Audiobook Download Directory**
+
+Server-side directory where audiobook torrents are downloaded (optional, uses Transmission default if not specified)
+
+- **Type:** string
+- **Default:** _none_
+
 #### `DELUGE_HOST`
 
 **Deluge Web UI Host/URL**
@@ -2148,6 +2214,15 @@ Label to assign to book downloads in Deluge
 - **Default:** `books`
 
 #### `DELUGE_CATEGORY_AUDIOBOOK`
+#### `DELUGE_SEPARATE_DOWNLOAD_DIRS`
+
+**Separate Book and Audiobook Directories**
+
+Download books and audiobooks to different directories instead of one shared directory.
+
+- **Type:** boolean
+- **Default:** `false`
+
 
 **Audiobook Label**
 
@@ -2157,6 +2232,7 @@ Label for audiobook downloads. Leave empty to use the book label.
 - **Default:** _empty string_
 
 #### `DELUGE_DOWNLOAD_DIR`
+#### `DELUGE_DOWNLOAD_DIR_BOOK`
 
 **Download Directory**
 
@@ -2165,6 +2241,23 @@ Server-side directory where torrents are downloaded (optional, uses Deluge defau
 - **Type:** string
 - **Default:** _none_
 
+
+**Book Download Directory**
+
+Server-side directory where book torrents are downloaded (optional, uses Deluge default if not specified)
+
+- **Type:** string
+- **Default:** _none_
+
+#### `DELUGE_DOWNLOAD_DIR_AUDIOBOOK`
+
+**Audiobook Download Directory**
+
+Server-side directory where audiobook torrents are downloaded (optional, uses Deluge default if not specified)
+
+- **Type:** string
+- **Default:** _none_
+
 #### `RTORRENT_URL`
 
 **rTorrent URL**
@@ -2202,6 +2295,15 @@ Label to assign to ebook downloads in rTorrent
 - **Default:** `cwabd`
 
 #### `RTORRENT_AUDIOBOOK_LABEL`
+#### `RTORRENT_SEPARATE_DOWNLOAD_DIRS`
+
+**Separate Book and Audiobook Directories**
+
+Download books and audiobooks to different directories instead of one shared directory.
+
+- **Type:** boolean
+- **Default:** `false`
+
 
 **Audiobook Label**
 
@@ -2211,6 +2313,7 @@ Label to assign to audiobook downloads in rTorrent (falls back to Book Label if
 - **Default:** _none_
 
 #### `RTORRENT_DOWNLOAD_DIR`
+#### `RTORRENT_DOWNLOAD_DIR_BOOK`
 
 **Download Directory**
 
@@ -2219,6 +2322,23 @@ Server-side directory where torrents are downloaded (optional, uses rTorrent def
 - **Type:** string
 - **Default:** _none_
 
+
+**Book Download Directory**
+
+Server-side directory where book torrents are downloaded (optional, uses rTorrent default if not specified)
+
+- **Type:** string
+- **Default:** _none_
+
+#### `RTORRENT_DOWNLOAD_DIR_AUDIOBOOK`
+
+**Audiobook Download Directory**
+
+Server-side directory where audiobook torrents are downloaded (optional, uses rTorrent default if not specified)
+
+- **Type:** string
+- **Default:** _none_
+
 #### `PROWLARR_TORRENT_ACTION`
 
 **Torrent Completion Action**

shelfmark/download/clients/_coercion.py

@@ -1,6 +1,6 @@
 """Shared coercion helpers for download client config and option values."""
 
-from shelfmark.core.utils import normalize_http_url
+from shelfmark.core.utils import is_audiobook, normalize_http_url
 
 
 def config_text(value: object, default: str = "") -> str:
@@ -12,6 +12,22 @@ def config_text(value: object, default: str = "") -> str:
     return str(value)
 
 
+def resolve_download_dir(
+    *,
+    separate: bool,
+    shared_dir: str,
+    book_dir: str,
+    audiobook_dir: str,
+    content_type: object,
+) -> str:
+    """Pick the client save directory; empty means use the client's own default."""
+    if not separate:
+        return shared_dir
+    if is_audiobook(content_type if isinstance(content_type, str) else None):
+        return audiobook_dir
+    return book_dir
+
+
 def normalize_http_config_url(value: object, *, require_string: bool = False) -> str:
     """Normalize HTTP(S) config URLs with optional strict string-only input handling."""
     if require_string and not isinstance(value, str):

shelfmark/download/clients/deluge.py

@@ -30,6 +30,7 @@ from shelfmark.download.clients._coercion import (
     coerce_optional_float,
     coerce_optional_int,
     config_text,
+    resolve_download_dir,
 )
 from shelfmark.download.clients.torrent_utils import (
     extract_torrent_info,
@@ -131,6 +132,9 @@ class DelugeClient(DownloadClient):
 
         self._category = config_text(config.get("DELUGE_CATEGORY", "books"), "books")
         self._download_dir = config_text(config.get("DELUGE_DOWNLOAD_DIR", ""))
+        self._separate_download_dirs = bool(config.get("DELUGE_SEPARATE_DOWNLOAD_DIRS", False))
+        self._download_dir_book = config_text(config.get("DELUGE_DOWNLOAD_DIR_BOOK", ""))
+        self._download_dir_audiobook = config_text(config.get("DELUGE_DOWNLOAD_DIR_AUDIOBOOK", ""))
 
     def _next_rpc_id(self) -> int:
         self._rpc_id += 1
@@ -286,8 +290,15 @@ class DelugeClient(DownloadClient):
                 _raise_runtime_error(message)
 
             options: dict[str, Any] = {}
-            if self._download_dir:
-                options["download_location"] = self._download_dir
+            download_dir = resolve_download_dir(
+                separate=self._separate_download_dirs,
+                shared_dir=self._download_dir,
+                book_dir=self._download_dir_book,
+                audiobook_dir=self._download_dir_audiobook,
+                content_type=kwargs.get("content_type"),
+            )
+            if download_dir:
+                options["download_location"] = download_dir
 
             # Per-torrent seeding limits from indexer
             seeding_time_limit = coerce_optional_int(kwargs.get("seeding_time_limit"))

shelfmark/download/clients/qbittorrent.py

@@ -23,6 +23,7 @@ from shelfmark.download.clients._coercion import (
     coerce_optional_int,
     config_text,
     normalize_http_config_url,
+    resolve_download_dir,
 )
 from shelfmark.download.clients.torrent_utils import (
     extract_torrent_info,
@@ -253,6 +254,11 @@ class QBittorrentClient(DownloadClient):
         )
         self._category = config_text(config.get("QBITTORRENT_CATEGORY", "books"))
         self._download_dir = config_text(config.get("QBITTORRENT_DOWNLOAD_DIR", ""))
+        self._separate_download_dirs = bool(config.get("QBITTORRENT_SEPARATE_DOWNLOAD_DIRS", False))
+        self._download_dir_book = config_text(config.get("QBITTORRENT_DOWNLOAD_DIR_BOOK", ""))
+        self._download_dir_audiobook = config_text(
+            config.get("QBITTORRENT_DOWNLOAD_DIR_AUDIOBOOK", "")
+        )
         self._tags = _normalize_tags(config.get("QBITTORRENT_TAG", []))
         # download_id -> qBittorrent's current primary hash, for identities that no
         # longer match it directly. See _resolve_torrent().
@@ -533,8 +539,15 @@ class QBittorrentClient(DownloadClient):
             add_kwargs: _QBittorrentAddKwargs = {"rename": name}
             if category:
                 add_kwargs["category"] = category
-            if self._download_dir:
-                add_kwargs["save_path"] = self._download_dir
+            download_dir = resolve_download_dir(
+                separate=self._separate_download_dirs,
+                shared_dir=self._download_dir,
+                book_dir=self._download_dir_book,
+                audiobook_dir=self._download_dir_audiobook,
+                content_type=kwargs.get("content_type"),
+            )
+            if download_dir:
+                add_kwargs["save_path"] = download_dir
             if tags:
                 add_kwargs["tags"] = ",".join(tags)
             if seeding_time_limit is not None:

shelfmark/download/clients/rtorrent.py

@@ -22,7 +22,11 @@ from shelfmark.download.clients import (
     DownloadStatus,
     register_client,
 )
-from shelfmark.download.clients._coercion import config_text, normalize_http_config_url
+from shelfmark.download.clients._coercion import (
+    config_text,
+    normalize_http_config_url,
+    resolve_download_dir,
+)
 from shelfmark.download.clients.torrent_utils import (
     extract_torrent_info,
 )
@@ -127,6 +131,11 @@ class RTorrentClient(DownloadClient):
         self._download_dir = config_text(config.get("RTORRENT_DOWNLOAD_DIR", ""))
         self._label = config_text(config.get("RTORRENT_LABEL", ""))
         self._audiobook_label = config_text(config.get("RTORRENT_AUDIOBOOK_LABEL", ""))
+        self._separate_download_dirs = bool(config.get("RTORRENT_SEPARATE_DOWNLOAD_DIRS", False))
+        self._download_dir_book = config_text(config.get("RTORRENT_DOWNLOAD_DIR_BOOK", ""))
+        self._download_dir_audiobook = config_text(
+            config.get("RTORRENT_DOWNLOAD_DIR_AUDIOBOOK", "")
+        )
 
     @staticmethod
     def is_configured() -> bool:
@@ -187,7 +196,16 @@ class RTorrentClient(DownloadClient):
                 logger.debug("Setting rTorrent label: %s", label)
                 commands.append(f"d.custom1.set={label}")
 
-            download_dir = self._download_dir or self._get_download_dir()
+            download_dir = (
+                resolve_download_dir(
+                    separate=self._separate_download_dirs,
+                    shared_dir=self._download_dir,
+                    book_dir=self._download_dir_book,
+                    audiobook_dir=self._download_dir_audiobook,
+                    content_type=content_type,
+                )
+                or self._get_download_dir()
+            )
             if download_dir:
                 logger.debug("Setting rTorrent download directory: %s", download_dir)
                 commands.append(f"d.directory.set={download_dir}")

shelfmark/download/clients/settings.py

@@ -8,6 +8,7 @@ from typing import TYPE_CHECKING, Any, NoReturn, Protocol, TypeGuard
 
 from shelfmark.core.settings_registry import (
     ActionButton,
+    CheckboxField,
     HeadingField,
     NumberField,
     PasswordField,
@@ -764,12 +765,42 @@ def prowlarr_clients_settings() -> list[SettingsField]:
             default="",
             show_when={"field": "PROWLARR_TORRENT_CLIENT", "value": "qbittorrent"},
         ),
+        CheckboxField(
+            key="QBITTORRENT_SEPARATE_DOWNLOAD_DIRS",
+            label="Separate Book and Audiobook Directories",
+            description="Download books and audiobooks to different directories instead of one shared directory.",
+            default=False,
+            show_when={"field": "PROWLARR_TORRENT_CLIENT", "value": "qbittorrent"},
+        ),
         TextField(
             key="QBITTORRENT_DOWNLOAD_DIR",
             label="Download Directory",
             description="Server-side directory where torrents are downloaded (optional, uses qBittorrent default if not specified)",
             placeholder="/downloads",
-            show_when={"field": "PROWLARR_TORRENT_CLIENT", "value": "qbittorrent"},
+            show_when=[
+                {"field": "PROWLARR_TORRENT_CLIENT", "value": "qbittorrent"},
+                {"field": "QBITTORRENT_SEPARATE_DOWNLOAD_DIRS", "value": False},
+            ],
+        ),
+        TextField(
+            key="QBITTORRENT_DOWNLOAD_DIR_BOOK",
+            label="Book Download Directory",
+            description="Server-side directory where book torrents are downloaded (optional, uses qBittorrent default if not specified)",
+            placeholder="/downloads/books",
+            show_when=[
+                {"field": "PROWLARR_TORRENT_CLIENT", "value": "qbittorrent"},
+                {"field": "QBITTORRENT_SEPARATE_DOWNLOAD_DIRS", "value": True},
+            ],
+        ),
+        TextField(
+            key="QBITTORRENT_DOWNLOAD_DIR_AUDIOBOOK",
+            label="Audiobook Download Directory",
+            description="Server-side directory where audiobook torrents are downloaded (optional, uses qBittorrent default if not specified)",
+            placeholder="/downloads/audiobooks",
+            show_when=[
+                {"field": "PROWLARR_TORRENT_CLIENT", "value": "qbittorrent"},
+                {"field": "QBITTORRENT_SEPARATE_DOWNLOAD_DIRS", "value": True},
+            ],
         ),
         TagListField(
             key="QBITTORRENT_TAG",
@@ -824,12 +855,42 @@ def prowlarr_clients_settings() -> list[SettingsField]:
             default="",
             show_when={"field": "PROWLARR_TORRENT_CLIENT", "value": "transmission"},
         ),
+        CheckboxField(
+            key="TRANSMISSION_SEPARATE_DOWNLOAD_DIRS",
+            label="Separate Book and Audiobook Directories",
+            description="Download books and audiobooks to different directories instead of one shared directory.",
+            default=False,
+            show_when={"field": "PROWLARR_TORRENT_CLIENT", "value": "transmission"},
+        ),
         TextField(
             key="TRANSMISSION_DOWNLOAD_DIR",
             label="Download Directory",
             description="Server-side directory where torrents are downloaded (optional, uses Transmission default if not specified)",
             placeholder="/downloads",
-            show_when={"field": "PROWLARR_TORRENT_CLIENT", "value": "transmission"},
+            show_when=[
+                {"field": "PROWLARR_TORRENT_CLIENT", "value": "transmission"},
+                {"field": "TRANSMISSION_SEPARATE_DOWNLOAD_DIRS", "value": False},
+            ],
+        ),
+        TextField(
+            key="TRANSMISSION_DOWNLOAD_DIR_BOOK",
+            label="Book Download Directory",
+            description="Server-side directory where book torrents are downloaded (optional, uses Transmission default if not specified)",
+            placeholder="/downloads/books",
+            show_when=[
+                {"field": "PROWLARR_TORRENT_CLIENT", "value": "transmission"},
+                {"field": "TRANSMISSION_SEPARATE_DOWNLOAD_DIRS", "value": True},
+            ],
+        ),
+        TextField(
+            key="TRANSMISSION_DOWNLOAD_DIR_AUDIOBOOK",
+            label="Audiobook Download Directory",
+            description="Server-side directory where audiobook torrents are downloaded (optional, uses Transmission default if not specified)",
+            placeholder="/downloads/audiobooks",
+            show_when=[
+                {"field": "PROWLARR_TORRENT_CLIENT", "value": "transmission"},
+                {"field": "TRANSMISSION_SEPARATE_DOWNLOAD_DIRS", "value": True},
+            ],
         ),
         # --- Deluge Settings ---
         TextField(
@@ -878,12 +939,42 @@ def prowlarr_clients_settings() -> list[SettingsField]:
             default="",
             show_when={"field": "PROWLARR_TORRENT_CLIENT", "value": "deluge"},
         ),
+        CheckboxField(
+            key="DELUGE_SEPARATE_DOWNLOAD_DIRS",
+            label="Separate Book and Audiobook Directories",
+            description="Download books and audiobooks to different directories instead of one shared directory.",
+            default=False,
+            show_when={"field": "PROWLARR_TORRENT_CLIENT", "value": "deluge"},
+        ),
         TextField(
             key="DELUGE_DOWNLOAD_DIR",
             label="Download Directory",
             description="Server-side directory where torrents are downloaded (optional, uses Deluge default if not specified)",
             placeholder="/downloads",
-            show_when={"field": "PROWLARR_TORRENT_CLIENT", "value": "deluge"},
+            show_when=[
+                {"field": "PROWLARR_TORRENT_CLIENT", "value": "deluge"},
+                {"field": "DELUGE_SEPARATE_DOWNLOAD_DIRS", "value": False},
+            ],
+        ),
+        TextField(
+            key="DELUGE_DOWNLOAD_DIR_BOOK",
+            label="Book Download Directory",
+            description="Server-side directory where book torrents are downloaded (optional, uses Deluge default if not specified)",
+            placeholder="/downloads/books",
+            show_when=[
+                {"field": "PROWLARR_TORRENT_CLIENT", "value": "deluge"},
+                {"field": "DELUGE_SEPARATE_DOWNLOAD_DIRS", "value": True},
+            ],
+        ),
+        TextField(
+            key="DELUGE_DOWNLOAD_DIR_AUDIOBOOK",
+            label="Audiobook Download Directory",
+            description="Server-side directory where audiobook torrents are downloaded (optional, uses Deluge default if not specified)",
+            placeholder="/downloads/audiobooks",
+            show_when=[
+                {"field": "PROWLARR_TORRENT_CLIENT", "value": "deluge"},
+                {"field": "DELUGE_SEPARATE_DOWNLOAD_DIRS", "value": True},
+            ],
         ),
         # --- rTorrent Settings ---
         TextField(
@@ -928,12 +1019,42 @@ def prowlarr_clients_settings() -> list[SettingsField]:
             placeholder="audiobooks",
             show_when={"field": "PROWLARR_TORRENT_CLIENT", "value": "rtorrent"},
         ),
+        CheckboxField(
+            key="RTORRENT_SEPARATE_DOWNLOAD_DIRS",
+            label="Separate Book and Audiobook Directories",
+            description="Download books and audiobooks to different directories instead of one shared directory.",
+            default=False,
+            show_when={"field": "PROWLARR_TORRENT_CLIENT", "value": "rtorrent"},
+        ),
         TextField(
             key="RTORRENT_DOWNLOAD_DIR",
             label="Download Directory",
             description="Server-side directory where torrents are downloaded (optional, uses rTorrent default if not specified)",
             placeholder="/downloads",
-            show_when={"field": "PROWLARR_TORRENT_CLIENT", "value": "rtorrent"},
+            show_when=[
+                {"field": "PROWLARR_TORRENT_CLIENT", "value": "rtorrent"},
+                {"field": "RTORRENT_SEPARATE_DOWNLOAD_DIRS", "value": False},
+            ],
+        ),
+        TextField(
+            key="RTORRENT_DOWNLOAD_DIR_BOOK",
+            label="Book Download Directory",
+            description="Server-side directory where book torrents are downloaded (optional, uses rTorrent default if not specified)",
+            placeholder="/downloads/books",
+            show_when=[
+                {"field": "PROWLARR_TORRENT_CLIENT", "value": "rtorrent"},
+                {"field": "RTORRENT_SEPARATE_DOWNLOAD_DIRS", "value": True},
+            ],
+        ),
+        TextField(
+            key="RTORRENT_DOWNLOAD_DIR_AUDIOBOOK",
+            label="Audiobook Download Directory",
+            description="Server-side directory where audiobook torrents are downloaded (optional, uses rTorrent default if not specified)",
+            placeholder="/downloads/audiobooks",
+            show_when=[
+                {"field": "PROWLARR_TORRENT_CLIENT", "value": "rtorrent"},
+                {"field": "RTORRENT_SEPARATE_DOWNLOAD_DIRS", "value": True},
+            ],
         ),
         # Note: Torrent client download path must be mounted identically in both containers.
         SelectField(

shelfmark/download/clients/transmission.py

@@ -21,6 +21,7 @@ from shelfmark.download.clients._coercion import (
     coerce_optional_int,
     config_text,
     normalize_http_config_url,
+    resolve_download_dir,
 )
 from shelfmark.download.clients.torrent_utils import (
     extract_torrent_info,
@@ -188,6 +189,13 @@ class TransmissionClient(DownloadClient):
         _apply_transmission_ssl_verify(self._client, url)
         self._category = config_text(config.get("TRANSMISSION_CATEGORY", "books"))
         self._download_dir = config_text(config.get("TRANSMISSION_DOWNLOAD_DIR", ""))
+        self._separate_download_dirs = bool(
+            config.get("TRANSMISSION_SEPARATE_DOWNLOAD_DIRS", False)
+        )
+        self._download_dir_book = config_text(config.get("TRANSMISSION_DOWNLOAD_DIR_BOOK", ""))
+        self._download_dir_audiobook = config_text(
+            config.get("TRANSMISSION_DOWNLOAD_DIR_AUDIOBOOK", "")
+        )
 
     @staticmethod
     def is_configured() -> bool:
@@ -238,8 +246,15 @@ class TransmissionClient(DownloadClient):
 
             if resolved_category:
                 add_kwargs["labels"] = [resolved_category]
-            if self._download_dir:
-                add_kwargs["download_dir"] = self._download_dir
+            download_dir = resolve_download_dir(
+                separate=self._separate_download_dirs,
+                shared_dir=self._download_dir,
+                book_dir=self._download_dir_book,
+                audiobook_dir=self._download_dir_audiobook,
+                content_type=kwargs.get("content_type"),
+            )
+            if download_dir:
+                add_kwargs["download_dir"] = download_dir
 
             if torrent_info.torrent_data:
                 torrent = self._client.add_torrent(

tests/prowlarr/test_download_dir_resolution.py

@@ -0,0 +1,44 @@
+"""Tests for per-content-type torrent client download directories."""
+
+import pytest
+
+from shelfmark.download.clients._coercion import resolve_download_dir
+
+
+@pytest.mark.parametrize(
+    ("separate", "content_type", "expected"),
+    [
+        (False, "audiobook", "/shared"),
+        (False, "ebook", "/shared"),
+        (False, None, "/shared"),
+        (True, "audiobook", "/audio"),
+        (True, "ebook", "/books"),
+        (True, None, "/books"),
+    ],
+)
+def test_resolve_download_dir(separate, content_type, expected):
+    assert (
+        resolve_download_dir(
+            separate=separate,
+            shared_dir="/shared",
+            book_dir="/books",
+            audiobook_dir="/audio",
+            content_type=content_type,
+        )
+        == expected
+    )
+
+
+def test_separate_dirs_do_not_fall_back_to_shared_dir():
+    """Empty per-type directories mean the client default, never the shared directory."""
+    for content_type in ("audiobook", "ebook"):
+        assert (
+            resolve_download_dir(
+                separate=True,
+                shared_dir="/shared",
+                book_dir="",
+                audiobook_dir="",
+                content_type=content_type,
+            )
+            == ""
+        )

tests/prowlarr/test_qbittorrent_client.py

@@ -1590,6 +1590,63 @@ class TestQBittorrentClientAddDownload:
                 call_kwargs = mock_client_instance.torrents_add.call_args.kwargs
                 assert call_kwargs.get("save_path") == "/downloads/books"
 
+    def test_add_download_uses_separate_book_and_audiobook_dirs(self, monkeypatch):
+        """With separate directories on, books and audiobooks use their own directories."""
+        config_values = {
+            "QBITTORRENT_URL": "http://localhost:8080",
+            "QBITTORRENT_USERNAME": "admin",
+            "QBITTORRENT_PASSWORD": "password",
+            "QBITTORRENT_CATEGORY": "books",
+            "QBITTORRENT_DOWNLOAD_DIR": "/downloads/shared",
+            "QBITTORRENT_SEPARATE_DOWNLOAD_DIRS": True,
+            "QBITTORRENT_DOWNLOAD_DIR_BOOK": "/downloads/books",
+            "QBITTORRENT_DOWNLOAD_DIR_AUDIOBOOK": "/downloads/audiobooks",
+        }
+        monkeypatch.setattr(
+            "shelfmark.download.clients.qbittorrent.config.get",
+            lambda key, default="": config_values.get(key, default),
+        )
+
+        valid_hash = "a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2"
+        mock_torrent = MockTorrent(hash_val=valid_hash)
+        mock_client_instance = MagicMock()
+        mock_client_instance.torrents_add.return_value = "Ok."
+        mock_client_instance._session.get.return_value = create_mock_session_response(
+            [mock_torrent], status_code=200
+        )
+        mock_client_class = MagicMock(return_value=mock_client_instance)
+
+        with patch.dict("sys.modules", {"qbittorrentapi": MagicMock(Client=mock_client_class)}):
+            import importlib
+
+            import shelfmark.download.clients.qbittorrent as qb_module
+
+            importlib.reload(qb_module)
+
+            with patch(
+                "shelfmark.download.clients.qbittorrent.extract_torrent_info",
+                autospec=True,
+            ) as mock_extract:
+                mock_extract.return_value = TorrentInfo(
+                    info_hash=valid_hash,
+                    torrent_data=None,
+                    is_magnet=True,
+                    magnet_url=f"magnet:?xt=urn:btih:{valid_hash}&dn=test",
+                )
+
+                client = qb_module.QBittorrentClient()
+                client.add_download(
+                    "magnet:?xt=urn:btih:test&dn=test", "Test", content_type="audiobook"
+                )
+                call_kwargs = mock_client_instance.torrents_add.call_args.kwargs
+                assert call_kwargs.get("save_path") == "/downloads/audiobooks"
+
+                client.add_download(
+                    "magnet:?xt=urn:btih:test&dn=test", "Test", content_type="ebook"
+                )
+                call_kwargs = mock_client_instance.torrents_add.call_args.kwargs
+                assert call_kwargs.get("save_path") == "/downloads/books"
+
 
 class TestQBittorrentClientRemove:
     """Tests for QBittorrentClient.remove()."""