add User.profile_id, implement in ATProto

atproto.py

@@ -109,6 +109,9 @@ class ATProto(User, Protocol):
 
         return did.resolve_handle(handle, get_fn=util.requests_get)
 
+    def profile_id(self):
+        return f'at://{self.key.id()}/app.bsky.actor.profile/self'
+
     @classmethod
     def target_for(cls, obj, shared=False):
         """Returns the PDS URL for the given object, or None.

models.py

@@ -398,6 +398,22 @@ class User(StringIdModel, metaclass=ProtocolUserMeta):
         """
         raise NotImplementedError()
 
+    def profile_id(self):
+        """Returns the id of this user's profile object in its native protocol.
+
+        Examples:
+
+        * Web: home page URL, eg ``https://me.com/``
+        * ActivityPub: actor URL, eg ``https://instance.com/users/me``
+        * ATProto: profile AT URI, eg ``at://did:plc:123/app.bsky.actor.profile/self``
+
+        Defaults to this user's key id.
+
+        Returns:
+          str
+        """
+        return self.key.id()
+
     def user_page_path(self, rest=None):
         """Returns the user's Bridgy Fed user page path."""
         path = f'/{self.ABBREV}/{self.readable_or_key_id()}'

tests/test_atproto.py

@@ -238,6 +238,10 @@ class ATProtoTest(TestCase):
         self.store_object(id='did:plc:foo', raw=DID_DOC)
         self.assertEqual('@han.dull@atproto.brid.gy', user.ap_address())
 
+    def test_profile_id(self):
+        self.assertEqual('at://did:plc:foo/app.bsky.actor.profile/self',
+                         self.make_user('did:plc:foo', cls=ATProto).profile_id())
+
     @patch.object(tasks_client, 'create_task', return_value=Task(name='my task'))
     @patch('requests.post',
            return_value=requests_response('OK'))  # create DID on PLC