Decouple blog models and BlogService from shared layer

Move Post/Author/Tag/PostAuthor/PostTag/PostUser models from
shared/models/ghost_content.py to blog/models/content.py so blog-domain
models no longer live in the shared layer. Replace the shared
SqlBlogService + BlogService protocol with a blog-local singleton
(blog_service), and switch entry_associations.py from direct DB access
to HTTP fetch_data("blog", "post-by-id") to respect the inter-service
boundary.

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

blog/alembic/env.py

@@ -2,7 +2,7 @@ from alembic import context
 from shared.db.alembic_env import run_alembic
 
 MODELS = [
-    "shared.models.ghost_content",
+    "blog.models.content",
     "shared.models.kv",
     "shared.models.menu_item",
     "shared.models.menu_node",

blog/app.py

@@ -134,7 +134,7 @@ def create_app() -> "Quart":
     async def oembed():
         from urllib.parse import urlparse
         from quart import jsonify
-        from shared.services.registry import services
+        from services import blog_service
         from shared.infrastructure.urls import blog_url
         from shared.infrastructure.oembed import build_oembed_response
 
@@ -147,7 +147,7 @@ def create_app() -> "Quart":
         if not slug:
             return jsonify({"error": "could not extract slug"}), 404
 
-        post = await services.blog.get_post_by_slug(g.s, slug)
+        post = await blog_service.get_post_by_slug(g.s, slug)
         if not post:
             return jsonify({"error": "not found"}), 404
 

blog/bp/data/routes.py

@@ -9,7 +9,7 @@ from quart import Blueprint, g, jsonify, request
 
 from shared.infrastructure.data_client import DATA_HEADER
 from shared.contracts.dtos import dto_to_dict
-from shared.services.registry import services
+from services import blog_service
 
 
 def register() -> Blueprint:
@@ -36,7 +36,7 @@ def register() -> Blueprint:
     # --- post-by-slug ---
     async def _post_by_slug():
         slug = request.args.get("slug", "")
-        post = await services.blog.get_post_by_slug(g.s, slug)
+        post = await blog_service.get_post_by_slug(g.s, slug)
         if not post:
             return None
         return dto_to_dict(post)
@@ -46,7 +46,7 @@ def register() -> Blueprint:
     # --- post-by-id ---
     async def _post_by_id():
         post_id = int(request.args.get("id", 0))
-        post = await services.blog.get_post_by_id(g.s, post_id)
+        post = await blog_service.get_post_by_id(g.s, post_id)
         if not post:
             return None
         return dto_to_dict(post)
@@ -59,7 +59,7 @@ def register() -> Blueprint:
         if not ids_raw:
             return []
         ids = [int(x.strip()) for x in ids_raw.split(",") if x.strip()]
-        posts = await services.blog.get_posts_by_ids(g.s, ids)
+        posts = await blog_service.get_posts_by_ids(g.s, ids)
         return [dto_to_dict(p) for p in posts]
 
     _handlers["posts-by-ids"] = _posts_by_ids
@@ -69,7 +69,7 @@ def register() -> Blueprint:
         query = request.args.get("query", "")
         page = int(request.args.get("page", 1))
         per_page = int(request.args.get("per_page", 10))
-        posts, total = await services.blog.search_posts(g.s, query, page, per_page)
+        posts, total = await blog_service.search_posts(g.s, query, page, per_page)
         return {"posts": [dto_to_dict(p) for p in posts], "total": total}
 
     _handlers["search-posts"] = _search_posts

blog/bp/fragments/routes.py

@@ -125,7 +125,7 @@ def register():
                          data_app="blog")
 
     async def _link_card_handler():
-        from shared.services.registry import services
+        from services import blog_service
         from shared.infrastructure.urls import blog_url
 
         slug = request.args.get("slug", "")
@@ -137,7 +137,7 @@ def register():
             parts = []
             for s in slugs:
                 parts.append(f"<!-- fragment:{s} -->")
-                post = await services.blog.get_post_by_slug(g.s, s)
+                post = await blog_service.get_post_by_slug(g.s, s)
                 if post:
                     parts.append(_blog_link_card_sx(post, blog_url(f"/{post.slug}")))
             return "\n".join(parts)
@@ -145,7 +145,7 @@ def register():
         # Single mode
         if not slug:
             return ""
-        post = await services.blog.get_post_by_slug(g.s, slug)
+        post = await blog_service.get_post_by_slug(g.s, slug)
         if not post:
             return ""
         return _blog_link_card_sx(post, blog_url(f"/{post.slug}"))

blog/bp/post/admin/routes.py

@@ -264,7 +264,7 @@ def register():
 
     # Get associated entry IDs for this post
     post_id = g.post_data["post"]["id"]
-    associated_entry_ids = await get_post_entry_ids(g.s, post_id)
+    associated_entry_ids = await get_post_entry_ids(post_id)
 
     html = await render_template(
       "_types/post/admin/_calendar_view.html",
@@ -293,7 +293,7 @@ def register():
     from sqlalchemy import select
 
     post_id = g.post_data["post"]["id"]
-    associated_entry_ids = await get_post_entry_ids(g.s, post_id)
+    associated_entry_ids = await get_post_entry_ids(post_id)
 
     # Load ALL calendars (not just this post's calendars)
     result = await g.s.execute(
@@ -332,7 +332,7 @@ def register():
     from quart import jsonify
 
     post_id = g.post_data["post"]["id"]
-    is_associated, error = await toggle_entry_association(g.s, post_id, entry_id)
+    is_associated, error = await toggle_entry_association(post_id, entry_id)
 
     if error:
       return jsonify({"message": error, "errors": {}}), 400
@@ -340,7 +340,7 @@ def register():
     await g.s.flush()
 
     # Return updated association status
-    associated_entry_ids = await get_post_entry_ids(g.s, post_id)
+    associated_entry_ids = await get_post_entry_ids(post_id)
 
     # Load ALL calendars
     result = await g.s.execute(
@@ -355,7 +355,7 @@ def register():
       await g.s.refresh(calendar, ["entries", "post"])
 
     # Fetch associated entries for nav display
-    associated_entries = await get_associated_entries(g.s, post_id)
+    associated_entries = await get_associated_entries(post_id)
 
     # Load calendars for this post (for nav display)
     calendars = (

blog/bp/post/services/markets.py

@@ -7,7 +7,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from shared.contracts.dtos import MarketPlaceDTO
 from shared.infrastructure.actions import call_action, ActionError
-from shared.services.registry import services
+from services import blog_service
 
 
 class MarketError(ValueError):
@@ -33,7 +33,7 @@ async def create_market(sess: AsyncSession, post_id: int, name: str) -> MarketPl
         raise MarketError("Market name must not be empty.")
     slug = slugify(name)
 
-    post = await services.blog.get_post_by_id(sess, post_id)
+    post = await blog_service.get_post_by_id(sess, post_id)
     if not post:
         raise MarketError(f"Post {post_id} does not exist.")
 
@@ -57,7 +57,7 @@ async def create_market(sess: AsyncSession, post_id: int, name: str) -> MarketPl
 
 
 async def soft_delete_market(sess: AsyncSession, post_slug: str, market_slug: str) -> bool:
-    post = await services.blog.get_post_by_slug(sess, post_slug)
+    post = await blog_service.get_post_by_slug(sess, post_slug)
     if not post:
         return False
 

blog/models/__init__.py

@@ -1,4 +1,4 @@
-from .ghost_content import Post, Author, Tag, PostAuthor, PostTag
+from .content import Post, Author, Tag, PostAuthor, PostTag, PostUser
 from .snippet import Snippet
 from .tag_group import TagGroup, TagGroupTag
 

blog/models/content.py

@@ -118,7 +118,7 @@ class Post(Base):
         secondary="post_authors",
         primaryjoin="Post.id==post_authors.c.post_id",
         secondaryjoin="Author.id==post_authors.c.author_id",
-        back_populates="posts",
+        back_populates="authors",
         order_by="PostAuthor.sort_order",
     )
 
@@ -204,5 +204,3 @@ class PostUser(Base):
         Integer, primary_key=True, index=True,
     )
     sort_order: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
-
-

blog/models/ghost_content.py

@@ -1,3 +1,3 @@
-from shared.models.ghost_content import (  # noqa: F401
+from .content import (  # noqa: F401
-    Tag, Post, Author, PostAuthor, PostTag,
+    Tag, Post, Author, PostAuthor, PostTag, PostUser,
 )

blog/scripts/final_ghost_sync.py

@@ -29,7 +29,7 @@ sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "..", "shared")
 from shared.db.base import Base  # noqa: E402
 from shared.db.session import get_session, get_account_session, _engine  # noqa: E402
 from shared.infrastructure.ghost_admin_token import make_ghost_admin_jwt  # noqa: E402
-from shared.models.ghost_content import Post, Author, Tag, PostUser, PostAuthor  # noqa: E402
+from blog.models.content import Post, Author, Tag, PostUser, PostAuthor  # noqa: E402
 from shared.models.user import User  # noqa: E402
 
 logging.basicConfig(

blog/services/__init__.py

@@ -1,6 +1,68 @@
 """Blog app service registration."""
 from __future__ import annotations
 
+from sqlalchemy import select, func
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from shared.contracts.dtos import PostDTO
+
+from models.content import Post
+
+
+def _post_to_dto(post: Post) -> PostDTO:
+    return PostDTO(
+        id=post.id,
+        slug=post.slug,
+        title=post.title,
+        status=post.status,
+        visibility=post.visibility,
+        is_page=post.is_page,
+        feature_image=post.feature_image,
+        html=post.html,
+        excerpt=post.excerpt,
+        custom_excerpt=post.custom_excerpt,
+        published_at=post.published_at,
+    )
+
+
+class SqlBlogService:
+    async def get_post_by_slug(self, session: AsyncSession, slug: str) -> PostDTO | None:
+        post = (
+            await session.execute(select(Post).where(Post.slug == slug))
+        ).scalar_one_or_none()
+        return _post_to_dto(post) if post else None
+
+    async def get_post_by_id(self, session: AsyncSession, id: int) -> PostDTO | None:
+        post = (
+            await session.execute(select(Post).where(Post.id == id))
+        ).scalar_one_or_none()
+        return _post_to_dto(post) if post else None
+
+    async def get_posts_by_ids(self, session: AsyncSession, ids: list[int]) -> list[PostDTO]:
+        if not ids:
+            return []
+        result = await session.execute(select(Post).where(Post.id.in_(ids)))
+        return [_post_to_dto(p) for p in result.scalars().all()]
+
+    async def search_posts(
+        self, session: AsyncSession, query: str, page: int = 1, per_page: int = 10,
+    ) -> tuple[list[PostDTO], int]:
+        if query:
+            count_stmt = select(func.count(Post.id)).where(Post.title.ilike(f"%{query}%"))
+            posts_stmt = select(Post).where(Post.title.ilike(f"%{query}%")).order_by(Post.title)
+        else:
+            count_stmt = select(func.count(Post.id))
+            posts_stmt = select(Post).order_by(Post.published_at.desc().nullslast())
+
+        total = (await session.execute(count_stmt)).scalar() or 0
+        offset = (page - 1) * per_page
+        result = await session.execute(posts_stmt.limit(per_page).offset(offset))
+        return [_post_to_dto(p) for p in result.scalars().all()], total
+
+
+# Module-level singleton — import this in blog code.
+blog_service = SqlBlogService()
+
 
 def register_domain_services() -> None:
     """Register services for the blog app.
@@ -8,12 +70,8 @@ def register_domain_services() -> None:
     Blog owns: Post, Tag, Author, PostAuthor, PostTag.
     Cross-app calls go over HTTP via call_action() / fetch_data().
     """
-    from shared.services.registry import services
-    from shared.services.blog_impl import SqlBlogService
-
-    services.blog = SqlBlogService()
-
     # Federation needed for AP shared infrastructure (activitypub blueprint)
+    from shared.services.registry import services
     if not services.has("federation"):
         from shared.services.federation_impl import SqlFederationService
         services.federation = SqlFederationService()

events/bp/calendar/routes.py

@@ -235,7 +235,7 @@ def register():
                 )
             ).scalars().all()
 
-            associated_entries = await get_associated_entries(g.s, post_id)
+            associated_entries = await get_associated_entries(post_id)
             nav_oob = render_post_nav_entries_oob(associated_entries, cals, post_data["post"])
             html = html + nav_oob
 

events/bp/calendar_entry/routes.py

@@ -135,7 +135,7 @@ def register():
         for post in entry_posts:
             # Get associated entries for this post
             from shared.services.entry_associations import get_associated_entries
-            associated_entries = await get_associated_entries(g.s, post.id)
+            associated_entries = await get_associated_entries(post.id)
 
             # Load calendars for this post
             from models.calendars import Calendar

events/bp/calendars/routes.py

@@ -84,7 +84,7 @@ def register():
                 )
             ).scalars().all()
 
-            associated_entries = await get_associated_entries(g.s, post_id)
+            associated_entries = await get_associated_entries(post_id)
             nav_oob = render_post_nav_entries_oob(associated_entries, cals, post_data["post"])
             html = html + nav_oob
 

shared/contracts/__init__.py

@@ -10,7 +10,6 @@ from .dtos import (
     CartSummaryDTO,
 )
 from .protocols import (
-    BlogService,
     CalendarService,
     MarketService,
     CartService,
@@ -24,7 +23,6 @@ __all__ = [
     "ProductDTO",
     "CartItemDTO",
     "CartSummaryDTO",
-    "BlogService",
     "CalendarService",
     "MarketService",
     "CartService",

shared/contracts/protocols.py

@@ -11,7 +11,6 @@ from typing import Protocol, runtime_checkable
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from .dtos import (
-    PostDTO,
     CalendarDTO,
     CalendarEntryDTO,
     TicketDTO,
@@ -29,17 +28,6 @@ from .dtos import (
 )
 
 
-@runtime_checkable
-class BlogService(Protocol):
-    async def get_post_by_slug(self, session: AsyncSession, slug: str) -> PostDTO | None: ...
-    async def get_post_by_id(self, session: AsyncSession, id: int) -> PostDTO | None: ...
-    async def get_posts_by_ids(self, session: AsyncSession, ids: list[int]) -> list[PostDTO]: ...
-
-    async def search_posts(
-        self, session: AsyncSession, query: str, page: int = 1, per_page: int = 10,
-    ) -> tuple[list[PostDTO], int]: ...
-
-
 @runtime_checkable
 class CalendarService(Protocol):
     async def calendars_for_container(

shared/models/__init__.py

@@ -10,7 +10,6 @@ from .ghost_membership_entities import (
     GhostNewsletter, UserNewsletter,
     GhostTier, GhostSubscription,
 )
-from .ghost_content import Tag, Post, Author, PostAuthor, PostTag
 from .page_config import PageConfig
 from .order import Order, OrderItem
 from .market import (

shared/services/blog_impl.py

@@ -1,65 +0,0 @@
-"""SQL-backed BlogService implementation.
-
-Queries ``shared.models.ghost_content.Post`` — only this module may read
-blog-domain tables on behalf of other domains.
-"""
-from __future__ import annotations
-
-from sqlalchemy import select, func
-from sqlalchemy.ext.asyncio import AsyncSession
-
-from shared.models.ghost_content import Post
-from shared.contracts.dtos import PostDTO
-
-
-def _post_to_dto(post: Post) -> PostDTO:
-    return PostDTO(
-        id=post.id,
-        slug=post.slug,
-        title=post.title,
-        status=post.status,
-        visibility=post.visibility,
-        is_page=post.is_page,
-        feature_image=post.feature_image,
-        html=post.html,
-        excerpt=post.excerpt,
-        custom_excerpt=post.custom_excerpt,
-        published_at=post.published_at,
-    )
-
-
-class SqlBlogService:
-    async def get_post_by_slug(self, session: AsyncSession, slug: str) -> PostDTO | None:
-        post = (
-            await session.execute(select(Post).where(Post.slug == slug))
-        ).scalar_one_or_none()
-        return _post_to_dto(post) if post else None
-
-    async def get_post_by_id(self, session: AsyncSession, id: int) -> PostDTO | None:
-        post = (
-            await session.execute(select(Post).where(Post.id == id))
-        ).scalar_one_or_none()
-        return _post_to_dto(post) if post else None
-
-    async def get_posts_by_ids(self, session: AsyncSession, ids: list[int]) -> list[PostDTO]:
-        if not ids:
-            return []
-        result = await session.execute(select(Post).where(Post.id.in_(ids)))
-        return [_post_to_dto(p) for p in result.scalars().all()]
-
-    async def search_posts(
-        self, session: AsyncSession, query: str, page: int = 1, per_page: int = 10,
-    ) -> tuple[list[PostDTO], int]:
-        """Search posts by title with pagination. Not part of the Protocol
-        (admin-only use in events), but provided for convenience."""
-        if query:
-            count_stmt = select(func.count(Post.id)).where(Post.title.ilike(f"%{query}%"))
-            posts_stmt = select(Post).where(Post.title.ilike(f"%{query}%")).order_by(Post.title)
-        else:
-            count_stmt = select(func.count(Post.id))
-            posts_stmt = select(Post).order_by(Post.published_at.desc().nullslast())
-
-        total = (await session.execute(count_stmt)).scalar() or 0
-        offset = (page - 1) * per_page
-        result = await session.execute(posts_stmt.limit(per_page).offset(offset))
-        return [_post_to_dto(p) for p in result.scalars().all()], total

shared/services/entry_associations.py

@@ -4,16 +4,12 @@ Only uses HTTP-based fetch_data/call_action, no direct DB access.
 """
 from __future__ import annotations
 
-from sqlalchemy.ext.asyncio import AsyncSession
-
 from shared.infrastructure.actions import call_action, ActionError
 from shared.infrastructure.data_client import fetch_data
 from shared.contracts.dtos import CalendarEntryDTO, dto_from_dict
-from shared.services.registry import services
 
 
 async def toggle_entry_association(
-    session: AsyncSession,
     post_id: int,
     entry_id: int
 ) -> tuple[bool, str | None]:
@@ -21,7 +17,7 @@ async def toggle_entry_association(
     Toggle association between a post and calendar entry.
     Returns (is_now_associated, error_message).
     """
-    post = await services.blog.get_post_by_id(session, post_id)
+    post = await fetch_data("blog", "post-by-id", params={"id": post_id}, required=False)
     if not post:
         return False, "Post not found"
 
@@ -35,7 +31,6 @@ async def toggle_entry_association(
 
 
 async def get_post_entry_ids(
-    session: AsyncSession,
     post_id: int
 ) -> set[int]:
     """
@@ -49,7 +44,6 @@ async def get_post_entry_ids(
 
 
 async def get_associated_entries(
-    session: AsyncSession,
     post_id: int,
     page: int = 1,
     per_page: int = 10

shared/services/registry.py

@@ -8,15 +8,14 @@ Usage::
     from shared.services.registry import services
 
     # Register at app startup (own domain only)
-    services.blog = SqlBlogService()
+    services.calendar = SqlCalendarService()
 
     # Use locally within the owning app
-    post = await services.blog.get_post_by_slug(session, slug)
+    cals = await services.calendar.calendars_for_container(session, "page", page_id)
 """
 from __future__ import annotations
 
 from shared.contracts.protocols import (
-    BlogService,
     CalendarService,
     MarketService,
     CartService,
@@ -33,23 +32,11 @@ class _ServiceRegistry:
     """
 
     def __init__(self) -> None:
-        self._blog: BlogService | None = None
         self._calendar: CalendarService | None = None
         self._market: MarketService | None = None
         self._cart: CartService | None = None
         self._federation: FederationService | None = None
 
-    # -- blog -----------------------------------------------------------------
-    @property
-    def blog(self) -> BlogService:
-        if self._blog is None:
-            raise RuntimeError("BlogService not registered")
-        return self._blog
-
-    @blog.setter
-    def blog(self, impl: BlogService) -> None:
-        self._blog = impl
-
     # -- calendar -------------------------------------------------------------
     @property
     def calendar(self) -> CalendarService: