diff --git a/tildes/tildes/json.py b/tildes/tildes/json.py
index 57313f3..7ec8a0b 100644
--- a/tildes/tildes/json.py
+++ b/tildes/tildes/json.py
@@ -11,6 +11,7 @@ from tildes.models import DatabaseModel
 from tildes.models.group import Group
 from tildes.models.topic import Topic
 from tildes.models.user import User
+from tildes.schemas.context import TildesSchemaContext, TildesContext
 
 
 def serialize_model(model_item: DatabaseModel, request: Request) -> dict:
@@ -25,11 +26,12 @@ def serialize_model(model_item: DatabaseModel, request: Request) -> dict:
 
 def serialize_topic(topic: Topic, request: Request) -> dict:
     """Return serializable data for a Topic."""
-    context = {}
+    context: TildesContext = {}
     if not request.has_permission("view_author", topic):
         context["hide_username"] = True
 
-    return topic.schema_class(context=context).dump(topic)
+    with TildesSchemaContext(context):
+        return topic.schema_class().dump(topic)
 
 
 def includeme(config: Configurator) -> None:
diff --git a/tildes/tildes/resources/group.py b/tildes/tildes/resources/group.py
index b95f964..5a4d8f6 100644
--- a/tildes/tildes/resources/group.py
+++ b/tildes/tildes/resources/group.py
@@ -10,12 +10,14 @@ from sqlalchemy_utils import Ltree
 
 from tildes.models.group import Group, GroupWikiPage
 from tildes.resources import get_resource
+from tildes.schemas.context import TildesSchemaContext, TildesContext
 from tildes.schemas.group import GroupSchema
 from tildes.views.decorators import use_kwargs
 
 
 @use_kwargs(
-    GroupSchema(only=("path",), context={"fix_path_capitalization": True}),
+    GroupSchema(only=("path",)),
+    context=TildesSchemaContext(TildesContext(fix_path_capitalization=True)),
     location="matchdict",
 )
 def group_by_path(request: Request, path: str) -> Group:
diff --git a/tildes/tildes/schemas/context.py b/tildes/tildes/schemas/context.py
new file mode 100644
index 0000000..495d900
--- /dev/null
+++ b/tildes/tildes/schemas/context.py
@@ -0,0 +1,30 @@
+# Copyright (c) 2018 Tildes contributors <code@tildes.net>
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+"""Context variables that can be used with Marshmallow schemas."""
+import typing
+
+from marshmallow.experimental.context import Context
+
+
+class TildesContext(typing.TypedDict, total=False):
+    """Context for Tildes Marshmallow schemas.
+
+    For convenience, we use one unified class instead of one per schema,
+    so it can be passed down through different schemas in a subgraph.
+    For example, if a Topic contains a reference to a User,
+    one instance of TildesContext can configure both the Topic and User.
+    """
+
+    # Applies to UserSchema
+    hide_username: bool
+    # Applies to UserSchema
+    check_breached_passwords: bool
+    # Applies to UserSchema
+    username_trim_whitespace: bool
+
+    # Applies to GroupSchema
+    fix_path_capitalization: bool
+
+
+TildesSchemaContext = Context[TildesContext]
diff --git a/tildes/tildes/schemas/group.py b/tildes/tildes/schemas/group.py
index 1659cb8..3d513b3 100644
--- a/tildes/tildes/schemas/group.py
+++ b/tildes/tildes/schemas/group.py
@@ -11,6 +11,7 @@ from marshmallow import pre_load, Schema, validates
 from marshmallow.exceptions import ValidationError
 from marshmallow.fields import DateTime
 
+from tildes.schemas.context import TildesSchemaContext, TildesContext
 from tildes.schemas.fields import Ltree, Markdown, SimpleString
 
 
@@ -44,7 +45,9 @@ class GroupSchema(Schema):
     def prepare_path(self, data: dict, many: bool, partial: Any) -> dict:
         """Prepare the path value before it's validated."""
         # pylint: disable=unused-argument
-        if not self.context.get("fix_path_capitalization"):
+        if not TildesSchemaContext.get(default=TildesContext()).get(
+            "fix_path_capitalization"
+        ):
             return data
 
         if "path" not in data or not isinstance(data["path"], str):
diff --git a/tildes/tildes/schemas/user.py b/tildes/tildes/schemas/user.py
index 44bf55f..239cd75 100644
--- a/tildes/tildes/schemas/user.py
+++ b/tildes/tildes/schemas/user.py
@@ -12,6 +12,7 @@ from marshmallow.fields import DateTime, Email, String
 from marshmallow.validate import Length, Regexp
 
 from tildes.lib.password import is_breached_password
+from tildes.schemas.context import TildesSchemaContext, TildesContext
 from tildes.schemas.fields import Markdown
 
 
@@ -63,7 +64,7 @@ class UserSchema(Schema):
     def anonymize_username(self, data: dict, many: bool) -> dict:
         """Hide the username if the dumping context specifies to do so."""
         # pylint: disable=unused-argument
-        if not self.context.get("hide_username"):
+        if not TildesSchemaContext.get(default=TildesContext()).get("hide_username"):
             return data
 
         if "username" not in data:
@@ -101,7 +102,9 @@ class UserSchema(Schema):
 
         Requires check_breached_passwords be True in the schema's context.
         """
-        if not self.context.get("check_breached_passwords"):
+        if not TildesSchemaContext.get(default=TildesContext()).get(
+            "check_breached_passwords"
+        ):
             return
 
         if is_breached_password(value):
@@ -117,7 +120,9 @@ class UserSchema(Schema):
         Requires username_trim_whitespace be True in the schema's context.
         """
         # pylint: disable=unused-argument
-        if not self.context.get("username_trim_whitespace"):
+        if not TildesSchemaContext.get(default=TildesContext()).get(
+            "username_trim_whitespace"
+        ):
             return data
 
         if "username" not in data:
diff --git a/tildes/tildes/views/api/web/user.py b/tildes/tildes/views/api/web/user.py
index 3ff8d87..a16a91a 100644
--- a/tildes/tildes/views/api/web/user.py
+++ b/tildes/tildes/views/api/web/user.py
@@ -23,6 +23,7 @@ from tildes.lib.datetime import SimpleHoursPeriod
 from tildes.lib.string import separate_string
 from tildes.models.log import Log
 from tildes.models.user import User, UserInviteCode
+from tildes.schemas.context import TildesSchemaContext, TildesContext
 from tildes.schemas.fields import Enum, ShortTimePeriod
 from tildes.schemas.topic import TopicSchema
 from tildes.schemas.user import UserSchema
@@ -54,12 +55,13 @@ def patch_change_password(
     user = request.context
 
     # enable checking the new password against the breached-passwords list
-    user.schema.context["check_breached_passwords"] = True
+    context: TildesContext = {"check_breached_passwords": True}
 
     if new_password != new_password_confirm:
         raise HTTPUnprocessableEntity("New password and confirmation do not match.")
 
-    user.change_password(old_password, new_password)
+    with TildesSchemaContext(context):
+        user.change_password(old_password, new_password)
 
     return Response("Your password has been updated")
 
diff --git a/tildes/tildes/views/decorators.py b/tildes/tildes/views/decorators.py
index 677d3b8..c6ad292 100644
--- a/tildes/tildes/views/decorators.py
+++ b/tildes/tildes/views/decorators.py
@@ -4,9 +4,10 @@
 """Contains decorators for view functions."""
 
 from collections.abc import Callable
-from typing import Any, Union
+from typing import Any
 
 from marshmallow import EXCLUDE
+from marshmallow.experimental.context import Context
 from marshmallow.fields import Field
 from marshmallow.schema import Schema
 from pyramid.httpexceptions import HTTPFound
@@ -14,9 +15,14 @@ from pyramid.request import Request
 from pyramid.view import view_config
 from webargs import pyramidparser
 
+from tildes.schemas.context import TildesSchemaContext, TildesContext
+
 
 def use_kwargs(
-    argmap: Union[Schema, dict[str, Field]], location: str = "query", **kwargs: Any
+    argmap: Schema | dict[str, Field],
+    location: str = "query",
+    context: Context[Any] | None = None,
+    **kwargs: Any
 ) -> Callable:
     """Wrap the webargs @use_kwargs decorator with preferred default modifications.
 
@@ -28,15 +34,19 @@ def use_kwargs(
     it just ignores them, instead of erroring when there's unexpected data (as there
     almost always is, especially because of Intercooler).
     """
-    # convert a dict argmap to a Schema (the same way webargs would on its own)
-    if isinstance(argmap, dict):
-        argmap = Schema.from_dict(argmap)()
+    if context is None:
+        context = TildesSchemaContext(TildesContext())
+
+    with context:
+        # convert a dict argmap to a Schema (the same way webargs would on its own)
+        if isinstance(argmap, dict):
+            argmap = Schema.from_dict(argmap)()
 
-    assert isinstance(argmap, Schema)  # tell mypy the type is more restricted now
+        assert isinstance(argmap, Schema)  # tell mypy the type is more restricted now
 
-    argmap.unknown = EXCLUDE
+        argmap.unknown = EXCLUDE
 
-    return pyramidparser.use_kwargs(argmap, location=location, **kwargs)
+        return pyramidparser.use_kwargs(argmap, location=location, **kwargs)
 
 
 def ic_view_config(**kwargs: Any) -> Callable:
diff --git a/tildes/tildes/views/login.py b/tildes/tildes/views/login.py
index ef68091..ba42336 100644
--- a/tildes/tildes/views/login.py
+++ b/tildes/tildes/views/login.py
@@ -19,6 +19,7 @@ from tildes.enums import LogEventType
 from tildes.metrics import incr_counter
 from tildes.models.log import Log
 from tildes.models.user import User
+from tildes.schemas.context import TildesSchemaContext, TildesContext
 from tildes.schemas.user import UserSchema
 from tildes.views.decorators import not_logged_in, rate_limit_view, use_kwargs
 
@@ -60,9 +61,8 @@ def finish_login(request: Request, user: User, redirect_url: str) -> HTTPFound:
     route_name="login", request_method="POST", permission=NO_PERMISSION_REQUIRED
 )
 @use_kwargs(
-    UserSchema(
-        only=("username", "password"), context={"username_trim_whitespace": True}
-    ),
+    UserSchema(only=("username", "password")),
+    context=TildesSchemaContext(TildesContext(username_trim_whitespace=True)),
     location="form",
 )
 @use_kwargs({"from_url": String(load_default="")}, location="form")
diff --git a/tildes/tildes/views/register.py b/tildes/tildes/views/register.py
index 4a44d88..527da50 100644
--- a/tildes/tildes/views/register.py
+++ b/tildes/tildes/views/register.py
@@ -15,6 +15,7 @@ from tildes.metrics import incr_counter
 from tildes.models.group import Group, GroupSubscription
 from tildes.models.log import Log
 from tildes.models.user import User, UserInviteCode
+from tildes.schemas.context import TildesSchemaContext, TildesContext
 from tildes.schemas.user import UserSchema
 from tildes.views.decorators import not_logged_in, rate_limit_view, use_kwargs
 
@@ -34,9 +35,8 @@ def get_register(request: Request, code: str) -> dict:
     route_name="register", request_method="POST", permission=NO_PERMISSION_REQUIRED
 )
 @use_kwargs(
-    UserSchema(
-        only=("username", "password"), context={"check_breached_passwords": True}
-    ),
+    UserSchema(only=("username", "password")),
+    context=TildesSchemaContext(TildesContext(check_breached_passwords=True)),
     location="form",
 )
 @use_kwargs(
diff --git a/tildes/tildes/views/settings.py b/tildes/tildes/views/settings.py
index 0af7577..42e0cdd 100644
--- a/tildes/tildes/views/settings.py
+++ b/tildes/tildes/views/settings.py
@@ -22,6 +22,7 @@ from tildes.models.comment import Comment, CommentLabel, CommentTree
 from tildes.models.group import Group
 from tildes.models.topic import Topic
 from tildes.models.user import User
+from tildes.schemas.context import TildesContext, TildesSchemaContext
 from tildes.schemas.user import (
     BIO_MAX_LENGTH,
     EMAIL_ADDRESS_NOTE_MAX_LENGTH,
@@ -151,12 +152,13 @@ def post_settings_password_change(
 ) -> Response:
     """Change the logged-in user's password."""
     # enable checking the new password against the breached-passwords list
-    request.user.schema.context["check_breached_passwords"] = True
+    context: TildesContext = {"check_breached_passwords": True}
 
     if new_password != new_password_confirm:
         raise HTTPUnprocessableEntity("New password and confirmation do not match.")
 
-    request.user.change_password(old_password, new_password)
+    with TildesSchemaContext(context):
+        request.user.change_password(old_password, new_password)
 
     return Response("Your password has been updated")