diff --git a/amanuensis/backend/article.py b/amanuensis/backend/article.py
index 53e82af..973c123 100644
--- a/amanuensis/backend/article.py
+++ b/amanuensis/backend/article.py
@@ -2,13 +2,20 @@
 Article query interface
 """
 
+from typing import Optional
+
 from sqlalchemy import select
 
 from amanuensis.db import *
 from amanuensis.errors import ArgumentError
 
 
-def create(db: DbContext, lexicon_id: int, user_id: int, character_id: int) -> Article:
+def create(
+    db: DbContext,
+    lexicon_id: int,
+    user_id: int,
+    character_id: Optional[int],
+) -> Article:
     """
     Create a new article in a lexicon.
     """
diff --git a/amanuensis/backend/character.py b/amanuensis/backend/character.py
index bedda1f..1b87b3b 100644
--- a/amanuensis/backend/character.py
+++ b/amanuensis/backend/character.py
@@ -2,6 +2,8 @@
 Character query interface
 """
 
+from typing import Optional
+
 from sqlalchemy import select, func
 
 from amanuensis.db import *
@@ -9,7 +11,11 @@ from amanuensis.errors import ArgumentError
 
 
 def create(
-    db: DbContext, lexicon_id: int, user_id: int, name: str, signature: str
+    db: DbContext,
+    lexicon_id: int,
+    user_id: int,
+    name: str,
+    signature: Optional[str],
 ) -> Character:
     """
     Create a new character for a user.
diff --git a/amanuensis/backend/lexicon.py b/amanuensis/backend/lexicon.py
index 925f5e9..18bbe84 100644
--- a/amanuensis/backend/lexicon.py
+++ b/amanuensis/backend/lexicon.py
@@ -13,7 +13,12 @@ from amanuensis.errors import ArgumentError
 RE_ALPHANUM_DASH_UNDER = re.compile(r"^[A-Za-z0-9-_]*$")
 
 
-def create(db: DbContext, name: str, title: str, prompt: str) -> Lexicon:
+def create(
+    db: DbContext,
+    name: str,
+    title: str,
+    prompt: str,
+) -> Lexicon:
     """
     Create a new lexicon.
     """
diff --git a/amanuensis/backend/membership.py b/amanuensis/backend/membership.py
index 511b138..7440353 100644
--- a/amanuensis/backend/membership.py
+++ b/amanuensis/backend/membership.py
@@ -8,7 +8,12 @@ from amanuensis.db import DbContext, Membership
 from amanuensis.errors import ArgumentError
 
 
-def create(db: DbContext, user_id: int, lexicon_id: int, is_editor: bool) -> Membership:
+def create(
+    db: DbContext,
+    user_id: int,
+    lexicon_id: int,
+    is_editor: bool,
+) -> Membership:
     """
     Create a new user membership in a lexicon.
     """
diff --git a/amanuensis/backend/post.py b/amanuensis/backend/post.py
index 53161b4..3544b90 100644
--- a/amanuensis/backend/post.py
+++ b/amanuensis/backend/post.py
@@ -10,7 +10,12 @@ from amanuensis.db import DbContext, Post
 from amanuensis.errors import ArgumentError
 
 
-def create(db: DbContext, lexicon_id: int, user_id: int, body: str) -> Post:
+def create(
+    db: DbContext,
+    lexicon_id: int,
+    user_id: int,
+    body: str,
+) -> Post:
     """
     Create a new post
     """
diff --git a/tests/conftest.py b/tests/conftest.py
index 68c8f78..a93b93c 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -11,7 +11,7 @@ import amanuensis.backend.user as userq
 
 
 @pytest.fixture
-def db():
+def db() -> DbContext:
     """Provides an initialized database in memory."""
     db = DbContext("sqlite:///:memory:", debug=False)
     db.create_all()
diff --git a/tests/test_article.py b/tests/test_article.py
index 8b7b6cf..b19a088 100644
--- a/tests/test_article.py
+++ b/tests/test_article.py
@@ -1,6 +1,7 @@
 import pytest
 
 from amanuensis.db import DbContext
+from amanuensis.db.models import Character, Lexicon, User
 import amanuensis.backend.article as artiq
 
 from amanuensis.errors import ArgumentError
@@ -9,18 +10,18 @@ from amanuensis.errors import ArgumentError
 def test_create_article(db: DbContext, make):
     """Test new article creation"""
     # Create two users in a shared lexicon
-    user1 = make.user()
-    user2 = make.user()
-    lexicon1 = make.lexicon()
+    user1: User = make.user()
+    user2: User = make.user()
+    lexicon1: Lexicon = make.lexicon()
     make.membership(user_id=user1.id, lexicon_id=lexicon1.id)
     make.membership(user_id=user2.id, lexicon_id=lexicon1.id)
-    char1_1 = make.character(lexicon_id=lexicon1.id, user_id=user1.id)
-    char1_2 = make.character(lexicon_id=lexicon1.id, user_id=user2.id)
+    char1_1: Character = make.character(lexicon_id=lexicon1.id, user_id=user1.id)
+    char1_2: Character = make.character(lexicon_id=lexicon1.id, user_id=user2.id)
 
     # Create a lexicon that only one user is in
-    lexicon2 = make.lexicon()
+    lexicon2: Lexicon = make.lexicon()
     make.membership(user_id=user2.id, lexicon_id=lexicon2.id)
-    char2_2 = make.character(lexicon_id=lexicon2.id, user_id=user2.id)
+    char2_2: Character = make.character(lexicon_id=lexicon2.id, user_id=user2.id)
 
     # User cannot create article for another user's character
     with pytest.raises(ArgumentError):
diff --git a/tests/test_character.py b/tests/test_character.py
index 55f33b1..dc50302 100644
--- a/tests/test_character.py
+++ b/tests/test_character.py
@@ -7,35 +7,44 @@ from amanuensis.errors import ArgumentError
 
 def test_create_character(db: DbContext, lexicon_with_editor, make):
     """Test creating a character."""
+    lexicon: Lexicon
+    user: User
     lexicon, user = lexicon_with_editor
-    kwargs = {
+    defaults: dict = {
         "db": db,
         "user_id": user.id,
         "lexicon_id": lexicon.id,
         "name": "Character Name",
         "signature": "Signature",
     }
+    kwargs: dict
 
     # Bad argument types
     with pytest.raises(ArgumentError):
-        charq.create(**{**kwargs, "name": b"bytestring"})
+        kwargs = {**defaults, "name": b"bytestring"}
+        charq.create(**kwargs)
     with pytest.raises(ArgumentError):
-        charq.create(**{**kwargs, "name": None})
+        kwargs = {**defaults, "name": None}
+        charq.create(**kwargs)
     with pytest.raises(ArgumentError):
-        charq.create(**{**kwargs, "signature": b"bytestring"})
+        kwargs = {**defaults, "signature": b"bytestring"}
+        charq.create(**kwargs)
 
     # Bad character name
     with pytest.raises(ArgumentError):
-        charq.create(**{**kwargs, "name": " "})
+        kwargs = {**defaults, "name": " "}
+        charq.create(**kwargs)
 
     # Signature is auto-populated
-    char = charq.create(**{**kwargs, "signature": None})
+    kwargs = {**defaults, "signature": None}
+    char = charq.create(**kwargs)
     assert char.signature is not None
 
     # User must be in lexicon
-    new_user = make.user()
+    new_user: User = make.user()
     with pytest.raises(ArgumentError):
-        charq.create(**{**kwargs, "user_id": new_user.id})
+        kwargs = {**defaults, "user_id": new_user.id}
+        charq.create(**kwargs)
 
 
 def test_character_limits(db: DbContext, lexicon_with_editor):
@@ -47,12 +56,14 @@ def test_character_limits(db: DbContext, lexicon_with_editor):
     # Set character limit to one and create a character
     lexicon.character_limit = 1
     db.session.commit()
-    char1 = charq.create(db, lexicon.id, user.id, "Test Character 1", signature=None)
+    char1: Character = charq.create(
+        db, lexicon.id, user.id, "Test Character 1", signature=None
+    )
     assert char1.id, "Failed to create character 1"
 
     # Creating a second character should fail
     with pytest.raises(ArgumentError):
-        char2 = charq.create(
+        char2: Character = charq.create(
             db, lexicon.id, user.id, "Test Character 2", signature=None
         )
         assert char2
@@ -65,7 +76,7 @@ def test_character_limits(db: DbContext, lexicon_with_editor):
 
     # Creating a third character should fail
     with pytest.raises(ArgumentError):
-        char3 = charq.create(
+        char3: Character = charq.create(
             db, lexicon.id, user.id, "Test Character 3", signature=None
         )
         assert char3
diff --git a/tests/test_lexicon.py b/tests/test_lexicon.py
index 0af9546..9e1c400 100644
--- a/tests/test_lexicon.py
+++ b/tests/test_lexicon.py
@@ -1,3 +1,4 @@
+from amanuensis.db.models import Lexicon
 import datetime
 
 import pytest
@@ -9,24 +10,37 @@ from amanuensis.errors import ArgumentError
 
 def test_create_lexicon(db: DbContext):
     """Test new game creation."""
-    kwargs = {"name": "Test", "title": None, "prompt": "A test Lexicon game"}
+    defaults: dict = {
+        "db": db,
+        "name": "Test",
+        "title": None,
+        "prompt": "A test Lexicon game",
+    }
+    kwargs: dict
+
     # Test name constraints
     with pytest.raises(ArgumentError):
-        lexiq.create(db, **{**kwargs, "name": None})
+        kwargs = {**defaults, "name": None}
+        lexiq.create(**kwargs)
     with pytest.raises(ArgumentError):
-        lexiq.create(db, **{**kwargs, "name": ""})
+        kwargs = {**defaults, "name": ""}
+        lexiq.create(**kwargs)
     with pytest.raises(ArgumentError):
-        lexiq.create(db, **{**kwargs, "name": " "})
+        kwargs = {**defaults, "name": " "}
+        lexiq.create(**kwargs)
     with pytest.raises(ArgumentError):
-        lexiq.create(db, **{**kwargs, "name": ".."})
+        kwargs = {**defaults, "name": ".."}
+        lexiq.create(**kwargs)
     with pytest.raises(ArgumentError):
-        lexiq.create(db, **{**kwargs, "name": "\x00"})
+        kwargs = {**defaults, "name": "\x00"}
+        lexiq.create(**kwargs)
     with pytest.raises(ArgumentError):
-        lexiq.create(db, **{**kwargs, "name": "space in name"})
+        kwargs = {**defaults, "name": "space in name"}
+        lexiq.create(**kwargs)
 
     # Validate that creation populates fields, including timestamps
     before = datetime.datetime.utcnow() - datetime.timedelta(seconds=1)
-    new_lexicon = lexiq.create(db, **kwargs)
+    new_lexicon: Lexicon = lexiq.create(**defaults)
     after = datetime.datetime.utcnow() + datetime.timedelta(seconds=1)
     assert new_lexicon
     assert new_lexicon.id is not None
@@ -36,5 +50,4 @@ def test_create_lexicon(db: DbContext):
 
     # No duplicate lexicon names
     with pytest.raises(ArgumentError):
-        duplicate = lexiq.create(db, **kwargs)
-        assert duplicate
+        lexiq.create(**defaults)
diff --git a/tests/test_membership.py b/tests/test_membership.py
index a86c79e..45e70a1 100644
--- a/tests/test_membership.py
+++ b/tests/test_membership.py
@@ -10,13 +10,13 @@ import amanuensis.backend.membership as memq
 def test_create_membership(db: DbContext, make):
     """Test joining a game."""
     # Set up a user and a lexicon
-    new_user = make.user()
+    new_user: User = make.user()
     assert new_user.id, "Failed to create user"
-    new_lexicon = make.lexicon()
+    new_lexicon: Lexicon = make.lexicon()
     assert new_lexicon.id, "Failed to create lexicon"
 
     # Add the user to the lexicon as an editor
-    mem = memq.create(db, new_user.id, new_lexicon.id, True)
+    mem: Membership = memq.create(db, new_user.id, new_lexicon.id, True)
     assert mem, "Failed to create membership"
 
     # Check that the user and lexicon are mutually visible in the ORM relationships
@@ -24,7 +24,7 @@ def test_create_membership(db: DbContext, make):
     assert any(map(lambda mem: mem.user == new_user, new_lexicon.memberships))
 
     # Check that the editor flag was set properly
-    editor = db(
+    editor: User = db(
         select(User)
         .join(User.memberships)
         .join(Membership.lexicon)
@@ -37,5 +37,4 @@ def test_create_membership(db: DbContext, make):
 
     # Check that joining twice is not allowed
     with pytest.raises(ArgumentError):
-        mem2 = memq.create(db, new_user.id, new_lexicon.id, False)
-        assert mem2
+        memq.create(db, new_user.id, new_lexicon.id, False)
diff --git a/tests/test_post.py b/tests/test_post.py
index bb0b61d..773b705 100644
--- a/tests/test_post.py
+++ b/tests/test_post.py
@@ -11,34 +11,47 @@ def test_create_post(db: DbContext, lexicon_with_editor):
     lexicon, editor = lexicon_with_editor
 
     # argument dictionary for post object
-    kwargs = {"lexicon_id": lexicon.id, "user_id": editor.id, "body": "body"}
+    defaults: dict = {
+        "db": db,
+        "lexicon_id": lexicon.id,
+        "user_id": editor.id,
+        "body": "body",
+    }
+    kwargs: dict
 
     # ids are integers
     with pytest.raises(ArgumentError):
-        postq.create(db, **{**kwargs, "user_id": "zero"})
+        kwargs = {**defaults, "user_id": "zero"}
+        postq.create(**kwargs)
     with pytest.raises(ArgumentError):
-        postq.create(db, **{**kwargs, "lexicon_id": "zero"})
+        kwargs = {**defaults, "lexicon_id": "zero"}
+        postq.create(**kwargs)
 
     # empty arguments don't work
     with pytest.raises(ArgumentError):
-        postq.create(db, **{**kwargs, "lexicon_id": ""})
+        kwargs = {**defaults, "lexicon_id": ""}
+        postq.create(**kwargs)
     with pytest.raises(ArgumentError):
-        postq.create(db, **{**kwargs, "user_id": ""})
+        kwargs = {**defaults, "user_id": ""}
+        postq.create(**kwargs)
     with pytest.raises(ArgumentError):
-        postq.create(db, **{**kwargs, "body": ""})
+        kwargs = {**defaults, "body": ""}
+        postq.create(**kwargs)
 
     # post with only whitespace doesn't work
     with pytest.raises(ArgumentError):
-        postq.create(db, **{**kwargs, "body": "    "})
+        kwargs = {**defaults, "body": "    "}
+        postq.create(**kwargs)
 
     # post creation works and populates fields
-    new_post = postq.create(db, **kwargs)
+    new_post = postq.create(**defaults)
     assert new_post
     assert new_post.lexicon_id is not None
     assert new_post.user_id is not None
     assert new_post.body is not None
 
     # post creation works when user is None
-    new_post = postq.create(db, **{**kwargs, "user_id": None})
+    kwargs = {**defaults, "user_id": None}
+    new_post = postq.create(**kwargs)
     assert new_post
     assert new_post.user_id is None
diff --git a/tests/test_user.py b/tests/test_user.py
index 71b483a..f1e8b76 100644
--- a/tests/test_user.py
+++ b/tests/test_user.py
@@ -1,3 +1,4 @@
+from amanuensis.db.models import User
 import pytest
 
 from amanuensis.db import DbContext
@@ -7,39 +8,45 @@ from amanuensis.errors import ArgumentError
 
 def test_create_user(db: DbContext):
     """Test new user creation."""
-    kwargs = {
+    defaults: dict = {
+        "db": db,
         "username": "username",
         "password": "password",
         "display_name": "User Name",
         "email": "user@example.com",
         "is_site_admin": False,
     }
+    kwargs: dict
 
     # Test length constraints
     with pytest.raises(ArgumentError):
-        userq.create(db, **{**kwargs, "username": "me"})
+        kwargs = {**defaults, "username": "me"}
+        userq.create(**kwargs)
     with pytest.raises(ArgumentError):
-        userq.create(
-            db, **{**kwargs, "username": "the right honorable user-name, esquire"}
-        )
+        kwargs = {**defaults, "username": "the right honorable user-name, esquire"}
+        userq.create(**kwargs)
+
     # Test allowed characters
     with pytest.raises(ArgumentError):
-        userq.create(db, **{**kwargs, "username": "user name"})
+        kwargs = {**defaults, "username": "user name"}
+        userq.create(**kwargs)
+
     # No password
     with pytest.raises(ArgumentError):
-        userq.create(db, **{**kwargs, "password": None})
+        kwargs = {**defaults, "password": None}
+        userq.create(**kwargs)
 
     # Valid creation works and populates fields
-    new_user = userq.create(db, **kwargs)
+    new_user = userq.create(**defaults)
     assert new_user
     assert new_user.id is not None
     assert new_user.created is not None
 
     # No duplicate usernames
     with pytest.raises(ArgumentError):
-        duplicate = userq.create(db, **kwargs)
+        userq.create(**defaults)
 
     # Missing display name populates with username
-    user2_kw = {**kwargs, "username": "user2", "display_name": None}
-    user2 = userq.create(db, **user2_kw)
+    user2_kw: dict = {**defaults, "username": "user2", "display_name": None}
+    user2: User = userq.create(**user2_kw)
     assert user2.display_name is not None