diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2c2ca60..809001a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
+## [Unreleased]
+
+### Added
+
+- **BookStack**: support syncing pages from a specific book via `bookstack:<book-id>`.
+
 ## [0.3.6] - 2026-05-28
 
 ### Added
diff --git a/README.md b/README.md
index 8e11a8f..26226fe 100644
--- a/README.md
+++ b/README.md
@@ -151,6 +151,7 @@ services:
 ```bash
 oikb sync github:owner/repo --kb-id your-kb-id
 oikb sync confluence:ENG --kb-id your-kb-id
+oikb sync bookstack:12 --kb-id your-kb-id
 oikb sync s3://bucket/prefix --kb-id your-kb-id
 oikb sync nextcloud:/Documents --kb-id your-kb-id
 oikb sync servicenow:incident --kb-id your-kb-id
diff --git a/docs/guide.md b/docs/guide.md
index 905d74a..cc2cde5 100644
--- a/docs/guide.md
+++ b/docs/guide.md
@@ -20,6 +20,7 @@ A complete guide to syncing content into Open WebUI Knowledge Bases.
   - [GitHub](#github)
   - [GitLab / Bitbucket](#gitlab--bitbucket)
   - [Confluence](#confluence)
+  - [BookStack](#bookstack)
   - [Cloud Storage (S3 / GCS / Azure)](#cloud-storage-s3--gcs--azure)
   - [SharePoint](#sharepoint)
   - [Nextcloud](#nextcloud)
@@ -250,6 +251,16 @@ oikb sync confluence:SPACE_KEY --kb-id your-kb-id
 
 Requires `CONFLUENCE_URL`, `CONFLUENCE_USERNAME`, and `CONFLUENCE_API_TOKEN`.
 
+### BookStack
+
+```bash
+oikb sync bookstack: --kb-id your-kb-id       # all pages
+oikb sync bookstack:12 --kb-id your-kb-id     # one book ID
+```
+
+Requires `BOOKSTACK_URL`, `BOOKSTACK_TOKEN_ID`, and `BOOKSTACK_TOKEN_SECRET`.
+Use one Knowledge Base per book if you want to combine multiple BookStack books in Open WebUI.
+
 ### Cloud Storage (S3 / GCS / Azure)
 
 ```bash
diff --git a/src/oikb/cli.py b/src/oikb/cli.py
index 39250e2..f8e2f7c 100644
--- a/src/oikb/cli.py
+++ b/src/oikb/cli.py
@@ -161,8 +161,9 @@ def _resolve_connector(source: str, branch: str | None = None, path: str | None
         return SalesforceConnector()
 
     if source.startswith("bookstack:"):
-        from oikb.connectors.bookstack import BookStackConnector
-        return BookStackConnector()
+        from oikb.connectors.bookstack import BookStackConnector, parse_bookstack_source
+        parsed = parse_bookstack_source(source)
+        return BookStackConnector(book_id=parsed.get("book_id"))
 
     if source.startswith("discourse:"):
         from oikb.connectors.discourse import DiscourseConnector, parse_discourse_source
diff --git a/src/oikb/connectors/bookstack.py b/src/oikb/connectors/bookstack.py
index 8d86c30..f8c8fd0 100644
--- a/src/oikb/connectors/bookstack.py
+++ b/src/oikb/connectors/bookstack.py
@@ -17,7 +17,13 @@
 class BookStackConnector(BaseConnector):
     """Sync pages from BookStack."""
 
-    def __init__(self, base_url: str | None = None, token_id: str | None = None, token_secret: str | None = None):
+    def __init__(
+        self,
+        base_url: str | None = None,
+        token_id: str | None = None,
+        token_secret: str | None = None,
+        book_id: str | None = None,
+    ):
         self._url = (base_url or os.environ.get("BOOKSTACK_URL", "")).rstrip("/")
         tid = token_id or os.environ.get("BOOKSTACK_TOKEN_ID", "")
         ts = token_secret or os.environ.get("BOOKSTACK_TOKEN_SECRET", "")
@@ -25,12 +31,16 @@ def __init__(self, base_url: str | None = None, token_id: str | None = None, tok
             raise ValueError("BookStack credentials required. Set BOOKSTACK_URL, BOOKSTACK_TOKEN_ID, BOOKSTACK_TOKEN_SECRET.")
         self._http = httpx.Client(base_url=self._url, headers={"Authorization": f"Token {tid}:{ts}"}, timeout=30.0)
         self._cache: dict[str, str] = {}
+        self.book_id = book_id
 
     def build_manifest(self) -> list[ManifestEntry]:
         entries: list[ManifestEntry] = []
         offset = 0
         while True:
-            resp = self._http.get("/api/pages", params={"count": 100, "offset": offset})
+            params: dict[str, int | str] = {"count": 100, "offset": offset}
+            if self.book_id:
+                params["filter[book_id]"] = self.book_id
+            resp = self._http.get("/api/pages", params=params)
             resp.raise_for_status()
             data = resp.json()
             for page in data.get("data", []):
@@ -57,4 +67,10 @@ def close(self) -> None:
 
 
 def parse_bookstack_source(source: str) -> dict[str, str | None]:
-    return {}
+    book_id = source.removeprefix("bookstack:")
+    if not book_id:
+        return {"book_id": None}
+
+    if not book_id.isdecimal():
+        raise ValueError("Invalid BookStack source. Expected a numeric book ID, e.g. bookstack:12")
+    return {"book_id": book_id}
diff --git a/tests/test_bookstack.py b/tests/test_bookstack.py
new file mode 100644
index 0000000..d05191a
--- /dev/null
+++ b/tests/test_bookstack.py
@@ -0,0 +1,79 @@
+import pytest
+import respx
+from httpx import Response
+
+from oikb.connectors.bookstack import BookStackConnector, parse_bookstack_source
+
+
+def test_parse_bookstack_source_without_book_id():
+    assert parse_bookstack_source("bookstack:") == {"book_id": None}
+
+
+def test_parse_bookstack_source_with_book_id():
+    assert parse_bookstack_source("bookstack:12") == {"book_id": "12"}
+
+
+@pytest.mark.parametrize("source", ["bookstack:abc", "bookstack:12,34", "bookstack:12/34"])
+def test_parse_bookstack_source_rejects_invalid_book_id(source):
+    with pytest.raises(ValueError, match="numeric book ID"):
+        parse_bookstack_source(source)
+
+
+@respx.mock
+def test_build_manifest_filters_by_book_id():
+    route = respx.get("https://bookstack.example/api/pages").mock(
+        return_value=Response(
+            200,
+            json={
+                "data": [
+                    {
+                        "id": 99,
+                        "book_id": 12,
+                        "name": "Filtered Page",
+                        "updated_at": "2026-07-14T12:00:00Z",
+                    }
+                ],
+                "total": 1,
+            },
+        )
+    )
+
+    connector = BookStackConnector(
+        base_url="https://bookstack.example",
+        token_id="id",
+        token_secret="secret",
+        book_id="12",
+    )
+    try:
+        manifest = connector.build_manifest()
+    finally:
+        connector.close()
+
+    params = route.calls[0].request.url.params
+    assert params["count"] == "100"
+    assert params["offset"] == "0"
+    assert params["filter[book_id]"] == "12"
+    assert len(manifest) == 1
+    assert manifest[0].filename == "99_Filtered Page.txt"
+
+
+@respx.mock
+def test_build_manifest_without_book_id_keeps_unfiltered_request():
+    route = respx.get("https://bookstack.example/api/pages").mock(
+        return_value=Response(200, json={"data": [], "total": 0})
+    )
+
+    connector = BookStackConnector(
+        base_url="https://bookstack.example",
+        token_id="id",
+        token_secret="secret",
+    )
+    try:
+        assert connector.build_manifest() == []
+    finally:
+        connector.close()
+
+    params = route.calls[0].request.url.params
+    assert params["count"] == "100"
+    assert params["offset"] == "0"
+    assert "filter[book_id]" not in params