diff --git a/apidemo/__init__.py b/apidemo/__init__.py
new file mode 100644
index 0000000..80cbae4
--- /dev/null
+++ b/apidemo/__init__.py
@@ -0,0 +1 @@
+# py-scopes: apidemo
diff --git a/demo/__init__.py b/demo/__init__.py
new file mode 100644
index 0000000..c326fba
--- /dev/null
+++ b/demo/__init__.py
@@ -0,0 +1,2 @@
+# py-scopes: demo
+
diff --git a/scopes/core/__init__.py b/scopes/core/__init__.py
index 1d165e4..b7b6e4b 100644
--- a/scopes/core/__init__.py
+++ b/scopes/core/__init__.py
@@ -1 +1,4 @@
 """package scopes.core"""
+
+from .core import *
+
diff --git a/scopes/core/actor.py b/scopes/core/actor.py
index 32c02dd..091e96c 100644
--- a/scopes/core/actor.py
+++ b/scopes/core/actor.py
@@ -14,7 +14,7 @@ async def loop(q, bhv):
 def create(bhv, group=None):
     q = asyncio.Queue()
     if group is None:
-        return q, asyncio.create_task(loop(q, bhv))
+        asyncio.create_task(loop(q, bhv))
     else:
         group.create_task(loop(q, bhv))
     return q
diff --git a/scopes/core/core.py b/scopes/core/core.py
new file mode 100644
index 0000000..50affe8
--- /dev/null
+++ b/scopes/core/core.py
@@ -0,0 +1,22 @@
+# scopes.core.core
+
+"""The scopes.core package"""
+
+import asyncio
+from dataclasses import dataclass
+from types import CoroutineType, FunctionType
+from typing import Any
+
+from scopes.util import keywords as k, Symbol
+
+@dataclass
+class Scope:
+
+    value: Any = 0
+    categ: tuple[Symbol, Symbol] = (k.csys, k.c00)
+    stage: Symbol = k.initial
+    proc: CoroutineType | None = None
+    program: dict[tuple[Symbol, Symbol], CoroutineType] = {}
+    syns: list[FunctionType] = []
+    environ: asyncio.Queue | None = None
+
diff --git a/scopes/shape.py b/scopes/shape.py
index 5e198ac..8642955 100644
--- a/scopes/shape.py
+++ b/scopes/shape.py
@@ -6,8 +6,8 @@ from scopes.util import keywords as k
 
 class Record:
 
-    headFields = ()     # to be defined by subclass
-    headFieldsAsKeywords = set()
+    headFields: tuple = ()     # to be defined by subclass
+    headFieldsAsKeywords: set[str] = set()
     defaultHeadValue = ''
 
     def __init__(self, *headValues, data=None, **kw):
diff --git a/scopes/testing.py b/scopes/testing.py
index 1bbe686..53d4cb3 100644
--- a/scopes/testing.py
+++ b/scopes/testing.py
@@ -1,6 +1,7 @@
 # scopes.testing
 
 """Common stuff (config, fixtures, ...) for testing"""
+
 import os, sys
 sys.path = [os.path.dirname(__file__)] + sys.path
 
diff --git a/tests/test_actor.py b/tests/test_core.py
similarity index 67%
rename from tests/test_actor.py
rename to tests/test_core.py
index c544bf7..37fbc58 100644
--- a/tests/test_actor.py
+++ b/tests/test_core.py
@@ -1,10 +1,11 @@
-# py-scopes: tests.test_actor
+# py-scopes: tests.test_core
 
-""" Tests for scopes.core.actor"""
+""" Tests for scopes.core modules, including e.g. actor, message"""
 
 import asyncio
 import pytest
 
+from scopes import core
 from scopes.core import actor, message
 from scopes.util import keywords as k
 
@@ -13,6 +14,7 @@ collector = []
 def show(msg):
     collector.append(msg)
 
+
 async def handle_basic(msg):
     match msg:
         case k.show: show(msg)
@@ -38,8 +40,20 @@ async def test_actor():
         await q2.put(k.show)
         await q1.put(k.quit)
         await q2.put(k.quit)
-        #await asyncio.wait([t1, t2])
-    print(collector)
+    #print(collector)
     assert len(collector) == 6
     assert collector[-1] == 'actor 1: Goodbye'
 
+
+def test_message():
+    msg = message.Message(k.test, k.data, 'person', '4711', 
+                  data=dict(firstName='Bob', lastName='Miller'))
+    assert msg.head['class'] is k.person
+    assert msg.addr() == (k.test, k.person, '4711')
+    assert msg.categ() == (k.test, k.person)
+
+
+def test_core():
+    sc = core.Scope()
+    assert sc.value == 0
+
diff --git a/tests/test_message.py b/tests/test_message.py
deleted file mode 100644
index fb6b7cf..0000000
--- a/tests/test_message.py
+++ /dev/null
@@ -1,16 +0,0 @@
-# py-scopes: tests.test_message
-
-"""Tests for messages and related stuff"""
-
-import pytest
-
-from scopes.util import keywords as k
-
-def test_message():
-    from scopes.core.message import Message
-    msg = Message(k.test, k.data, 'person', '4711', 
-                  data=dict(firstName='Bob', lastName='Miller'))
-    assert msg.head['class'] is k.person
-    assert msg.addr() == (k.test, k.person, '4711')
-    assert msg.categ() == (k.test, k.person)
-