diff --git a/bookwyrm/activitypub/book.py b/bookwyrm/activitypub/book.py
index 49f2deb81..60d36bd02 100644
--- a/bookwyrm/activitypub/book.py
+++ b/bookwyrm/activitypub/book.py
@@ -55,7 +55,6 @@ class Work(Book):
 @dataclass(init=False)
 class Author(ActivityObject):
     ''' author of a book '''
-    url: str
     name: str
     born: str
     died: str
diff --git a/bookwyrm/incoming.py b/bookwyrm/incoming.py
index 5f4cc15b1..c6a22caa1 100644
--- a/bookwyrm/incoming.py
+++ b/bookwyrm/incoming.py
@@ -62,6 +62,8 @@ def shared_inbox(request):
         'Announce': handle_boost,
         'Add': {
             'Tag': handle_tag,
+            'Edition': handle_shelve,
+            'Work': handle_shelve,
         },
         'Undo': {
             'Follow': handle_unfollow,
@@ -318,6 +320,22 @@ def handle_tag(activity):
         status_builder.create_tag(user, book, activity['object']['name'])
 
 
+@app.task
+def handle_shelve(activity):
+    ''' putting a book on a shelf '''
+    user = get_or_create_remote_user(activity['actor'])
+    book = books_manager.get_or_create_book(activity['object'])
+    try:
+        shelf = models.Shelf.objects.get(remote_id=activity['target'])
+    except models.Shelf.DoesNotExist:
+        return
+    if shelf.user != user:
+        # this doesn't add up.
+        return
+    shelf.books.add(book)
+    shelf.save()
+
+
 @app.task
 def handle_update_user(activity):
     ''' receive an updated user Person activity object '''
diff --git a/bookwyrm/models/base_model.py b/bookwyrm/models/base_model.py
index 8150d650c..2215a28a9 100644
--- a/bookwyrm/models/base_model.py
+++ b/bookwyrm/models/base_model.py
@@ -68,7 +68,10 @@ class ActivitypubMixin:
             if not hasattr(self, mapping.model_key) or not mapping.activity_key:
                 continue
             value = getattr(self, mapping.model_key)
-            if hasattr(value, 'remote_id'):
+            print(value)
+            if hasattr(value, 'local_id'):
+                value = value.local_id
+            elif hasattr(value, 'remote_id'):
                 value = value.remote_id
             if isinstance(value, datetime):
                 value = value.isoformat()
diff --git a/bookwyrm/models/book.py b/bookwyrm/models/book.py
index b6261b8b7..93d9393de 100644
--- a/bookwyrm/models/book.py
+++ b/bookwyrm/models/book.py
@@ -56,7 +56,7 @@ class Book(ActivitypubMixin, BookWyrmModel):
     @property
     def ap_authors(self):
         ''' the activitypub serialization should be a list of author ids '''
-        return [a.remote_id for a in self.authors.all()]
+        return [a.local_id for a in self.authors.all()]
 
     @property
     def ap_cover(self):
@@ -73,7 +73,7 @@ class Book(ActivitypubMixin, BookWyrmModel):
         return self.parent_work.local_id
 
     activity_mappings = [
-        ActivityMapping('id', 'remote_id'),
+        ActivityMapping('id', 'local_id'),
 
         ActivityMapping('authors', 'ap_authors'),
         ActivityMapping('first_published_date', 'first_published_date'),
@@ -258,7 +258,7 @@ class Author(ActivitypubMixin, BookWyrmModel):
         an instance, so it needs a local url for federation. but it still needs
         the remote_id for easier deduplication and, if appropriate, to sync with
         the remote canonical copy (ditto here for author)'''
-        return 'https://%s/book/%d' % (DOMAIN, self.id)
+        return 'https://%s/author/%d' % (DOMAIN, self.id)
 
     @property
     def display_name(self):
@@ -271,8 +271,7 @@ class Author(ActivitypubMixin, BookWyrmModel):
         return self.last_name or self.first_name
 
     activity_mappings = [
-        ActivityMapping('id', 'remote_id'),
-        ActivityMapping('url', 'remote_id'),
+        ActivityMapping('id', 'local_id'),
         ActivityMapping('name', 'display_name'),
         ActivityMapping('born', 'born'),
         ActivityMapping('died', 'died'),
diff --git a/bookwyrm/models/shelf.py b/bookwyrm/models/shelf.py
index 53e557eea..24f1fdced 100644
--- a/bookwyrm/models/shelf.py
+++ b/bookwyrm/models/shelf.py
@@ -49,8 +49,8 @@ class ShelfBook(BookWyrmModel):
         return activitypub.Add(
             id='%s#add' % self.remote_id,
             actor=user.remote_id,
-            object=self.book.to_activity(),
-            target=self.shelf.to_activity()
+            object=self.book.local_id,
+            target=self.shelf.remote_id,
         ).serialize()
 
     def to_remove_activity(self, user):