Auto-mount fragment handlers: eliminate fragment blueprint boilerplate across all 8 services

Fragment read API is now fully declarative — every handler is a defhandler
s-expression dispatched through one shared auto_mount_fragment_handlers()
function. Replaces 8 near-identical blueprint files (~35 lines each) with
a single function call per service. Events Python handlers (container-cards,
account-page) extracted to a standalone module.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

account/app.py

@@ -8,7 +8,7 @@ from jinja2 import FileSystemLoader, ChoiceLoader
 
 from shared.infrastructure.factory import create_base_app
 
-from bp import register_account_bp, register_auth_bp, register_fragments
+from bp import register_account_bp, register_auth_bp
 
 
 async def account_context() -> dict:
@@ -86,7 +86,8 @@ def create_app() -> "Quart":
     from shared.sx.pages import auto_mount_pages
     auto_mount_pages(app, "account")
 
-    app.register_blueprint(register_fragments())
+    from shared.sx.handlers import auto_mount_fragment_handlers
+    auto_mount_fragment_handlers(app, "account")
 
     from bp.actions.routes import register as register_actions
     app.register_blueprint(register_actions())

account/bp/__init__.py

@@ -1,3 +1,2 @@
 from .account.routes import register as register_account_bp
 from .auth.routes import register as register_auth_bp
-from .fragments import register_fragments

account/bp/fragments/__init__.py

@@ -1 +0,0 @@
-from .routes import register as register_fragments

account/bp/fragments/routes.py

@@ -1,36 +0,0 @@
-"""Account app fragment endpoints.
-
-Exposes sx fragments at ``/internal/fragments/<type>`` for consumption
-by other coop apps via the fragment client.
-
-All handlers are defined declaratively in .sx files under
-``account/sx/handlers/`` and dispatched via the sx handler registry.
-"""
-
-from __future__ import annotations
-
-from quart import Blueprint, Response, request
-
-from shared.infrastructure.fragments import FRAGMENT_HEADER
-from shared.sx.handlers import get_handler, execute_handler
-
-
-def register():
-    bp = Blueprint("fragments", __name__, url_prefix="/internal/fragments")
-
-    @bp.before_request
-    async def _require_fragment_header():
-        if not request.headers.get(FRAGMENT_HEADER):
-            return Response("", status=403)
-
-    @bp.get("/<fragment_type>")
-    async def get_fragment(fragment_type: str):
-        handler_def = get_handler("account", fragment_type)
-        if handler_def is not None:
-            result = await execute_handler(
-                handler_def, "account", args=dict(request.args),
-            )
-            return Response(result, status=200, content_type="text/sx")
-        return Response("", status=200, content_type="text/sx")
-
-    return bp

blog/app.py

@@ -16,7 +16,6 @@ from bp import (
     register_admin,
     register_menu_items,
     register_snippets,
-    register_fragments,
     register_data,
     register_actions,
 )
@@ -108,7 +107,9 @@ def create_app() -> "Quart":
     app.register_blueprint(register_admin("/settings"))
     app.register_blueprint(register_menu_items())
     app.register_blueprint(register_snippets())
-    app.register_blueprint(register_fragments())
+    from shared.sx.handlers import auto_mount_fragment_handlers
+    auto_mount_fragment_handlers(app, "blog")
+
     app.register_blueprint(register_data())
     app.register_blueprint(register_actions())
 

blog/bp/__init__.py

@@ -2,6 +2,5 @@ from .blog.routes import register as register_blog_bp
 from .admin.routes import register as register_admin
 from .menu_items.routes import register as register_menu_items
 from .snippets.routes import register as register_snippets
-from .fragments import register_fragments
 from .data import register_data
 from .actions.routes import register as register_actions

blog/bp/fragments/__init__.py

@@ -1 +0,0 @@
-from .routes import register as register_fragments

blog/bp/fragments/routes.py

@@ -1,36 +0,0 @@
-"""Blog app fragment endpoints.
-
-Exposes sx fragments at ``/internal/fragments/<type>`` for consumption
-by other coop apps via the fragment client.
-
-All handlers are defined declaratively in .sx files under
-``blog/sx/handlers/`` and dispatched via the sx handler registry.
-"""
-
-from __future__ import annotations
-
-from quart import Blueprint, Response, request
-
-from shared.infrastructure.fragments import FRAGMENT_HEADER
-from shared.sx.handlers import get_handler, execute_handler
-
-
-def register():
-    bp = Blueprint("fragments", __name__, url_prefix="/internal/fragments")
-
-    @bp.before_request
-    async def _require_fragment_header():
-        if not request.headers.get(FRAGMENT_HEADER):
-            return Response("", status=403)
-
-    @bp.get("/<fragment_type>")
-    async def get_fragment(fragment_type: str):
-        handler_def = get_handler("blog", fragment_type)
-        if handler_def is not None:
-            result = await execute_handler(
-                handler_def, "blog", args=dict(request.args),
-            )
-            return Response(result, status=200, content_type="text/sx")
-        return Response("", status=200, content_type="text/sx")
-
-    return bp

cart/app.py

@@ -17,7 +17,6 @@ from bp import (
     register_page_cart,
     register_cart_global,
     register_page_admin,
-    register_fragments,
     register_actions,
     register_data,
     register_inbox,
@@ -141,7 +140,9 @@ def create_app() -> "Quart":
     app.jinja_env.globals["cart_quantity_url"] = lambda product_id: f"/quantity/{product_id}/"
     app.jinja_env.globals["cart_delete_url"] = lambda product_id: f"/delete/{product_id}/"
 
-    app.register_blueprint(register_fragments())
+    from shared.sx.handlers import auto_mount_fragment_handlers
+    auto_mount_fragment_handlers(app, "cart")
+
     app.register_blueprint(register_actions())
     app.register_blueprint(register_data())
     app.register_blueprint(register_inbox())

cart/bp/__init__.py

@@ -2,7 +2,6 @@ from .cart.overview_routes import register as register_cart_overview
 from .cart.page_routes import register as register_page_cart
 from .cart.global_routes import register as register_cart_global
 from .page_admin.routes import register as register_page_admin
-from .fragments import register_fragments
 from .actions import register_actions
 from .data import register_data
 from .inbox import register_inbox

cart/bp/fragments/__init__.py

@@ -1 +0,0 @@
-from .routes import register as register_fragments

cart/bp/fragments/routes.py

@@ -1,36 +0,0 @@
-"""Cart app fragment endpoints.
-
-Exposes sx fragments at ``/internal/fragments/<type>`` for consumption
-by other coop apps via the fragment client.
-
-All handlers are defined declaratively in .sx files under
-``cart/sx/handlers/`` and dispatched via the sx handler registry.
-"""
-
-from __future__ import annotations
-
-from quart import Blueprint, Response, request
-
-from shared.infrastructure.fragments import FRAGMENT_HEADER
-from shared.sx.handlers import get_handler, execute_handler
-
-
-def register():
-    bp = Blueprint("fragments", __name__, url_prefix="/internal/fragments")
-
-    @bp.before_request
-    async def _require_fragment_header():
-        if not request.headers.get(FRAGMENT_HEADER):
-            return Response("", status=403)
-
-    @bp.get("/<fragment_type>")
-    async def get_fragment(fragment_type: str):
-        handler_def = get_handler("cart", fragment_type)
-        if handler_def is not None:
-            result = await execute_handler(
-                handler_def, "cart", args=dict(request.args),
-            )
-            return Response(result, status=200, content_type="text/sx")
-        return Response("", status=200, content_type="text/sx")
-
-    return bp

events/app.py

@@ -9,7 +9,7 @@ from jinja2 import FileSystemLoader, ChoiceLoader
 
 from shared.infrastructure.factory import create_base_app
 
-from bp import register_all_events, register_calendar, register_calendars, register_markets, register_page, register_fragments, register_actions, register_data
+from bp import register_all_events, register_calendar, register_calendars, register_markets, register_page, register_actions, register_data
 
 
 async def events_context() -> dict:
@@ -112,7 +112,12 @@ def create_app() -> "Quart":
         url_prefix="/<slug>/markets",
     )
 
-    app.register_blueprint(register_fragments())
+    from shared.sx.handlers import auto_mount_fragment_handlers
+    from bp.fragments.python_handlers import container_cards_handler, account_page_handler
+    add_fragment_handler = auto_mount_fragment_handlers(app, "events")
+    add_fragment_handler("container-cards", container_cards_handler, content_type="text/html")
+    add_fragment_handler("account-page", account_page_handler)
+
     app.register_blueprint(register_actions())
     app.register_blueprint(register_data())
 

events/bp/__init__.py

@@ -3,6 +3,5 @@ from .calendar.routes import register as register_calendar
 from .calendars.routes import register as register_calendars
 from .markets.routes import register as register_markets
 from .page.routes import register as register_page
-from .fragments import register_fragments
 from .actions import register_actions
 from .data import register_data

events/bp/fragments/__init__.py

@@ -1 +0,0 @@
-from .routes import register as register_fragments

events/bp/fragments/python_handlers.py

@@ -0,0 +1,58 @@
+"""Python fragment handlers for events.
+
+These handlers call domain services and use sx_call() for rendering,
+so they can't be expressed as declarative .sx handlers.
+"""
+
+from __future__ import annotations
+
+from quart import g, request
+
+from shared.services.registry import services
+
+
+async def container_cards_handler():
+    """Container-cards fragment: entries for blog listing cards.
+
+    Returns text/html with <!-- card-widget:POST_ID --> comment markers
+    so the blog consumer can split per-post fragments.
+    """
+    from sx.sx_components import render_fragment_container_cards
+
+    post_ids_raw = request.args.get("post_ids", "")
+    post_slugs_raw = request.args.get("post_slugs", "")
+    post_ids = [int(x) for x in post_ids_raw.split(",") if x.strip()]
+    post_slugs = [x.strip() for x in post_slugs_raw.split(",") if x.strip()]
+    if not post_ids:
+        return ""
+
+    slug_map = {}
+    for i, pid in enumerate(post_ids):
+        slug_map[pid] = post_slugs[i] if i < len(post_slugs) else ""
+
+    batch = await services.calendar.confirmed_entries_for_posts(g.s, post_ids)
+    return render_fragment_container_cards(batch, post_ids, slug_map)
+
+
+async def account_page_handler():
+    """Account-page fragment: tickets or bookings panel.
+
+    Returns text/sx — the account app embeds this as sx source.
+    """
+    from sx.sx_components import (
+        render_fragment_account_tickets,
+        render_fragment_account_bookings,
+    )
+
+    slug = request.args.get("slug", "")
+    user_id = request.args.get("user_id", type=int)
+    if not user_id:
+        return ""
+
+    if slug == "tickets":
+        tickets = await services.calendar.user_tickets(g.s, user_id=user_id)
+        return render_fragment_account_tickets(tickets)
+    elif slug == "bookings":
+        bookings = await services.calendar.user_bookings(g.s, user_id=user_id)
+        return render_fragment_account_bookings(bookings)
+    return ""

events/bp/fragments/routes.py

@@ -1,104 +0,0 @@
-"""Events app fragment endpoints.
-
-Exposes sx fragments at ``/internal/fragments/<type>`` for consumption
-by other coop apps via the fragment client.
-
-All handlers are defined declaratively in .sx files under
-``events/sx/handlers/`` and dispatched via the sx handler registry.
-
-container-cards and account-page remain as Python handlers because they
-call domain service methods and return batched/conditional content, but
-they use sx_call() for rendering (no Jinja templates).
-"""
-
-from __future__ import annotations
-
-from quart import Blueprint, Response, g, request
-
-from shared.infrastructure.fragments import FRAGMENT_HEADER
-from shared.services.registry import services
-from shared.sx.handlers import get_handler, execute_handler
-
-
-def register():
-    bp = Blueprint("fragments", __name__, url_prefix="/internal/fragments")
-
-    _handlers: dict[str, object] = {}
-
-    # Fragment types that return HTML (comment-delimited batch)
-    _html_types = {"container-cards"}
-
-    @bp.before_request
-    async def _require_fragment_header():
-        if not request.headers.get(FRAGMENT_HEADER):
-            return Response("", status=403)
-
-    @bp.get("/<fragment_type>")
-    async def get_fragment(fragment_type: str):
-        # 1. Check Python handlers first
-        handler = _handlers.get(fragment_type)
-        if handler is not None:
-            result = await handler()
-            ct = "text/html" if fragment_type in _html_types else "text/sx"
-            return Response(result, status=200, content_type=ct)
-
-        # 2. Check sx handler registry
-        handler_def = get_handler("events", fragment_type)
-        if handler_def is not None:
-            result = await execute_handler(
-                handler_def, "events", args=dict(request.args),
-            )
-            return Response(result, status=200, content_type="text/sx")
-
-        return Response("", status=200, content_type="text/sx")
-
-    # --- container-cards fragment: entries for blog listing cards -----------
-    # Returns text/html with <!-- card-widget:POST_ID --> comment markers
-    # so the blog consumer can split per-post fragments.
-
-    async def _container_cards_handler():
-        from sx.sx_components import render_fragment_container_cards
-
-        post_ids_raw = request.args.get("post_ids", "")
-        post_slugs_raw = request.args.get("post_slugs", "")
-        post_ids = [int(x) for x in post_ids_raw.split(",") if x.strip()]
-        post_slugs = [x.strip() for x in post_slugs_raw.split(",") if x.strip()]
-        if not post_ids:
-            return ""
-
-        slug_map = {}
-        for i, pid in enumerate(post_ids):
-            slug_map[pid] = post_slugs[i] if i < len(post_slugs) else ""
-
-        batch = await services.calendar.confirmed_entries_for_posts(g.s, post_ids)
-        return render_fragment_container_cards(batch, post_ids, slug_map)
-
-    _handlers["container-cards"] = _container_cards_handler
-
-    # --- account-page fragment: tickets or bookings panel ------------------
-    # Returns text/sx — the account app embeds this as sx source.
-
-    async def _account_page_handler():
-        from sx.sx_components import (
-            render_fragment_account_tickets,
-            render_fragment_account_bookings,
-        )
-
-        slug = request.args.get("slug", "")
-        user_id = request.args.get("user_id", type=int)
-        if not user_id:
-            return ""
-
-        if slug == "tickets":
-            tickets = await services.calendar.user_tickets(g.s, user_id=user_id)
-            return render_fragment_account_tickets(tickets)
-        elif slug == "bookings":
-            bookings = await services.calendar.user_bookings(g.s, user_id=user_id)
-            return render_fragment_account_bookings(bookings)
-        return ""
-
-    _handlers["account-page"] = _account_page_handler
-
-    bp._fragment_handlers = _handlers
-
-    return bp

federation/app.py

@@ -12,7 +12,6 @@ from shared.services.registry import services
 from bp import (
     register_identity_bp,
     register_social_bp,
-    register_fragments,
 )
 
 
@@ -99,7 +98,8 @@ def create_app() -> "Quart":
     from shared.sx.pages import auto_mount_pages
     auto_mount_pages(app, "federation")
 
-    app.register_blueprint(register_fragments())
+    from shared.sx.handlers import auto_mount_fragment_handlers
+    auto_mount_fragment_handlers(app, "federation")
 
     # --- home page ---
     @app.get("/")

federation/bp/__init__.py

@@ -1,3 +1,2 @@
 from .identity.routes import register as register_identity_bp
 from .social.routes import register as register_social_bp
-from .fragments import register_fragments

federation/bp/fragments/__init__.py

@@ -1 +0,0 @@
-from .routes import register as register_fragments

federation/bp/fragments/routes.py

@@ -1,36 +0,0 @@
-"""Federation app fragment endpoints.
-
-Exposes sx fragments at ``/internal/fragments/<type>`` for consumption
-by other coop apps via the fragment client.
-
-All handlers are defined declaratively in .sx files under
-``federation/sx/handlers/`` and dispatched via the sx handler registry.
-"""
-
-from __future__ import annotations
-
-from quart import Blueprint, Response, request
-
-from shared.infrastructure.fragments import FRAGMENT_HEADER
-from shared.sx.handlers import get_handler, execute_handler
-
-
-def register():
-    bp = Blueprint("fragments", __name__, url_prefix="/internal/fragments")
-
-    @bp.before_request
-    async def _require_fragment_header():
-        if not request.headers.get(FRAGMENT_HEADER):
-            return Response("", status=403)
-
-    @bp.get("/<fragment_type>")
-    async def get_fragment(fragment_type: str):
-        handler_def = get_handler("federation", fragment_type)
-        if handler_def is not None:
-            result = await execute_handler(
-                handler_def, "federation", args=dict(request.args),
-            )
-            return Response(result, status=200, content_type="text/sx")
-        return Response("", status=200, content_type="text/sx")
-
-    return bp

market/app.py

@@ -11,7 +11,7 @@ from sqlalchemy import select
 from shared.infrastructure.factory import create_base_app
 from shared.config import config
 
-from bp import register_market_bp, register_all_markets, register_page_markets, register_page_admin, register_fragments, register_actions, register_data
+from bp import register_market_bp, register_all_markets, register_page_markets, register_page_admin, register_actions, register_data
 
 
 async def market_context() -> dict:
@@ -126,7 +126,9 @@ def create_app() -> "Quart":
         url_prefix="/<page_slug>/<market_slug>",
     )
 
-    app.register_blueprint(register_fragments())
+    from shared.sx.handlers import auto_mount_fragment_handlers
+    auto_mount_fragment_handlers(app, "market")
+
     app.register_blueprint(register_actions())
     app.register_blueprint(register_data())
 

market/bp/__init__.py

@@ -3,6 +3,5 @@ from .product.routes import register as register_product
 from .all_markets.routes import register as register_all_markets
 from .page_markets.routes import register as register_page_markets
 from .page_admin.routes import register as register_page_admin
-from .fragments import register_fragments
 from .actions import register_actions
 from .data import register_data

market/bp/fragments/__init__.py

@@ -1 +0,0 @@
-from .routes import register as register_fragments

market/bp/fragments/routes.py

@@ -1,36 +0,0 @@
-"""Market app fragment endpoints.
-
-Exposes sx fragments at ``/internal/fragments/<type>`` for consumption
-by other coop apps via the fragment client.
-
-All handlers are defined declaratively in .sx files under
-``market/sx/handlers/`` and dispatched via the sx handler registry.
-"""
-
-from __future__ import annotations
-
-from quart import Blueprint, Response, request
-
-from shared.infrastructure.fragments import FRAGMENT_HEADER
-from shared.sx.handlers import get_handler, execute_handler
-
-
-def register():
-    bp = Blueprint("fragments", __name__, url_prefix="/internal/fragments")
-
-    @bp.before_request
-    async def _require_fragment_header():
-        if not request.headers.get(FRAGMENT_HEADER):
-            return Response("", status=403)
-
-    @bp.get("/<fragment_type>")
-    async def get_fragment(fragment_type: str):
-        handler_def = get_handler("market", fragment_type)
-        if handler_def is not None:
-            result = await execute_handler(
-                handler_def, "market", args=dict(request.args),
-            )
-            return Response(result, status=200, content_type="text/sx")
-        return Response("", status=200, content_type="text/sx")
-
-    return bp

orders/app.py

@@ -14,7 +14,6 @@ from bp import (
     register_orders,
     register_order,
     register_checkout,
-    register_fragments,
     register_actions,
     register_data,
 )
@@ -77,7 +76,9 @@ def create_app() -> "Quart":
     from sxc.pages import setup_orders_pages
     setup_orders_pages()
 
-    app.register_blueprint(register_fragments())
+    from shared.sx.handlers import auto_mount_fragment_handlers
+    auto_mount_fragment_handlers(app, "orders")
+
     app.register_blueprint(register_actions())
     app.register_blueprint(register_data())
 

orders/bp/__init__.py

@@ -3,4 +3,3 @@ from .orders.routes import register as register_orders
 from .checkout.routes import register as register_checkout
 from .data.routes import register as register_data
 from .actions.routes import register as register_actions
-from .fragments.routes import register as register_fragments

orders/bp/fragments/routes.py

@@ -1,36 +0,0 @@
-"""Orders app fragment endpoints.
-
-Exposes sx fragments at ``/internal/fragments/<type>`` for consumption
-by other coop apps via the fragment client.
-
-All handlers are defined declaratively in .sx files under
-``orders/sx/handlers/`` and dispatched via the sx handler registry.
-"""
-
-from __future__ import annotations
-
-from quart import Blueprint, Response, request
-
-from shared.infrastructure.fragments import FRAGMENT_HEADER
-from shared.sx.handlers import get_handler, execute_handler
-
-
-def register():
-    bp = Blueprint("fragments", __name__, url_prefix="/internal/fragments")
-
-    @bp.before_request
-    async def _require_fragment_header():
-        if not request.headers.get(FRAGMENT_HEADER):
-            return Response("", status=403)
-
-    @bp.get("/<fragment_type>")
-    async def get_fragment(fragment_type: str):
-        handler_def = get_handler("orders", fragment_type)
-        if handler_def is not None:
-            result = await execute_handler(
-                handler_def, "orders", args=dict(request.args),
-            )
-            return Response(result, status=200, content_type="text/sx")
-        return Response("", status=200, content_type="text/sx")
-
-    return bp

relations/app.py

@@ -4,7 +4,7 @@ import sx.sx_components as sx_components  # noqa: F401  # ensure Hypercorn --rel
 
 from shared.infrastructure.factory import create_base_app
 
-from bp import register_actions, register_data, register_fragments
+from bp import register_actions, register_data
 from services import register_domain_services
 
 
@@ -16,7 +16,9 @@ def create_app() -> "Quart":
 
     app.register_blueprint(register_actions())
     app.register_blueprint(register_data())
-    app.register_blueprint(register_fragments())
+
+    from shared.sx.handlers import auto_mount_fragment_handlers
+    auto_mount_fragment_handlers(app, "relations")
 
     return app
 

relations/bp/__init__.py

@@ -1,3 +1,2 @@
 from .data.routes import register as register_data
 from .actions.routes import register as register_actions
-from .fragments.routes import register as register_fragments

relations/bp/fragments/routes.py

@@ -1,36 +0,0 @@
-"""Relations app fragment endpoints.
-
-Exposes sx fragments at ``/internal/fragments/<type>`` for consumption
-by other coop apps via the fragment client.
-
-All handlers are defined declaratively in .sx files under
-``relations/sx/handlers/`` and dispatched via the sx handler registry.
-"""
-
-from __future__ import annotations
-
-from quart import Blueprint, Response, request
-
-from shared.infrastructure.fragments import FRAGMENT_HEADER
-from shared.sx.handlers import get_handler, execute_handler
-
-
-def register():
-    bp = Blueprint("fragments", __name__, url_prefix="/internal/fragments")
-
-    @bp.before_request
-    async def _require_fragment_header():
-        if not request.headers.get(FRAGMENT_HEADER):
-            return Response("", status=403)
-
-    @bp.get("/<fragment_type>")
-    async def get_fragment(fragment_type: str):
-        handler_def = get_handler("relations", fragment_type)
-        if handler_def is not None:
-            result = await execute_handler(
-                handler_def, "relations", args=dict(request.args),
-            )
-            return Response(result, status=200, content_type="text/sx")
-        return Response("", status=200, content_type="text/sx")
-
-    return bp

shared/sx/handlers.py

@@ -204,3 +204,42 @@ def create_handler_blueprint(service_name: str) -> Any:
     bp._python_handlers = _python_handlers  # type: ignore[attr-defined]
 
     return bp
+
+
+# ---------------------------------------------------------------------------
+# Direct app mount — replaces per-service fragment blueprint boilerplate
+# ---------------------------------------------------------------------------
+
+def auto_mount_fragment_handlers(app: Any, service_name: str) -> Callable:
+    """Mount ``/internal/fragments/<type>`` directly on the app.
+
+    Returns an ``add_handler(name, fn, content_type)`` function for
+    registering Python handler overrides (checked before SX handlers).
+    """
+    from quart import Response, request
+    from shared.infrastructure.fragments import FRAGMENT_HEADER
+
+    python_handlers: dict[str, Callable[[], Awaitable[str]]] = {}
+    html_types: set[str] = set()
+
+    @app.get("/internal/fragments/<fragment_type>")
+    async def _fragment_dispatch(fragment_type: str):
+        if not request.headers.get(FRAGMENT_HEADER):
+            return Response("", status=403)
+        py = python_handlers.get(fragment_type)
+        if py is not None:
+            result = await py()
+            ct = "text/html" if fragment_type in html_types else "text/sx"
+            return Response(result, status=200, content_type=ct)
+        hdef = get_handler(service_name, fragment_type)
+        if hdef is not None:
+            result = await execute_handler(hdef, service_name, args=dict(request.args))
+            return Response(result, status=200, content_type="text/sx")
+        return Response("", status=200, content_type="text/sx")
+
+    def add_handler(name: str, fn: Callable[[], Awaitable[str]], content_type: str = "text/sx") -> None:
+        python_handlers[name] = fn
+        if content_type == "text/html":
+            html_types.add(name)
+
+    return add_handler