diff --git a/backend/app/routers/inventory.py b/backend/app/routers/inventory.py
index 410738a..d105262 100644
--- a/backend/app/routers/inventory.py
+++ b/backend/app/routers/inventory.py
@@ -1,5 +1,7 @@
-from fastapi import APIRouter, HTTPException, Query
+from fastapi import APIRouter, Depends, HTTPException, Query
+from sqlalchemy.orm import Session
 
+from app.database import get_db
 from app.schemas import EntityResponse, InventoryTreeNode, ListResponse, NodeContext, Relation
 from app.services.inventory import build_inventory_tree, build_node_context, get_badges, get_node_relations
 
@@ -10,30 +12,35 @@ router = APIRouter(prefix='/inventory', tags=['inventory'])
 def inventory_tree(
     root_id: str | None = None,
     depth: int | None = Query(default=None, ge=0),
-) -> ListResponse[InventoryTreeNode]:
-    items = build_inventory_tree(root_id=root_id, depth=depth)
+    db: Session = Depends(get_db),
+):
+    items = build_inventory_tree(db, root_id=root_id, depth=depth)
     return ListResponse(count=len(items), items=items)
 
 
 @router.get('/tree/{item_id}', response_model=EntityResponse[InventoryTreeNode])
-def inventory_subtree(item_id: str, depth: int | None = Query(default=None, ge=0)) -> EntityResponse[InventoryTreeNode]:
-    items = build_inventory_tree(root_id=item_id, depth=depth)
+def inventory_subtree(
+    item_id: str,
+    depth: int | None = Query(default=None, ge=0),
+    db: Session = Depends(get_db),
+):
+    items = build_inventory_tree(db, root_id=item_id, depth=depth)
     if not items:
         raise HTTPException(status_code=404, detail='Inventory node not found')
     return EntityResponse(item=items[0])
 
 
 @router.get('/nodes/{item_id}/context', response_model=EntityResponse[NodeContext])
-def node_context(item_id: str) -> EntityResponse[NodeContext]:
-    item = build_node_context(item_id)
+def node_context(item_id: str, db: Session = Depends(get_db)):
+    item = build_node_context(db, item_id)
     if not item:
         raise HTTPException(status_code=404, detail='Inventory node not found')
     return EntityResponse(item=item)
 
 
 @router.get('/nodes/{item_id}/badges', response_model=ListResponse[str])
-def node_badges(item_id: str) -> ListResponse[str]:
-    badges = get_badges(item_id)
+def node_badges(item_id: str, db: Session = Depends(get_db)):
+    badges = get_badges(db, item_id)
     return ListResponse(count=len(badges), items=badges)
 
 
@@ -43,6 +50,7 @@ def node_relations(
     layer: str | None = None,
     type: str | None = Query(default=None),
     direction: str = Query(default='both', pattern='^(incoming|outgoing|both)$'),
-) -> ListResponse[Relation]:
-    items = get_node_relations(item_id, layer=layer, rel_type=type, direction=direction)
+    db: Session = Depends(get_db),
+):
+    items = get_node_relations(db, item_id, layer=layer, rel_type=type, direction=direction)
     return ListResponse(count=len(items), items=items)