diff --git a/pagerite/data.py b/pagerite/data.py
index 9a105fc..056b4ad 100644
--- a/pagerite/data.py
+++ b/pagerite/data.py
@@ -2,8 +2,9 @@
 
 The site structure is a tree of Nodes. Every node is a menu label with a
 configurable title and slug (its key in the parent's ``children``); the
-URL path is the chain of slugs from the top level. ``content`` is the
-node's Markdown page, or None for a pure category label, whose URL renders
+URL path is the chain of slugs from the top level. ``chunks`` is the
+node's Markdown page as ordered content-hash keys into ``Data.chunks``
+(docs/migrate.md), or None for a pure category label, whose URL renders
 a placeholder page while nav links point at its first child.
 """
 
@@ -11,6 +12,16 @@ from datetime import UTC, datetime
 
 import msgspec
 
+from pagerite.chunks import join_chunks
+
+
+class Patch(msgspec.Struct, omit_defaults=True):
+    """One editing session's overrides on a translated view, applied
+    independently per hunk (docs/localization.md)."""
+
+    #: (search, replace) pairs on the served hybrid Markdown.
+    hunks: list[tuple[str, str]] = []
+
 
 class Node(msgspec.Struct, omit_defaults=True):
     """One item of the site hierarchy.
@@ -28,9 +39,21 @@ class Node(msgspec.Struct, omit_defaults=True):
 
     title: str = ""
     order: float = 0
-    #: Markdown source of the node's page; None = pure category label
-    #: (its URL renders a placeholder page).
-    content: str | None = None
+    #: Ordered chunk hashes into ``Data.chunks``; None = pure category
+    #: label (its URL renders a placeholder page), a list (possibly
+    #: empty) = a page.
+    chunks: list[str] | None = None
+    #: Primary language of the article (BCP-47 base tag). "" = inherit
+    #: (nearest ancestor, front page last, site default "en" final).
+    language: str = ""
+    #: Chunk hashes the editor marked "do not translate" (always served
+    #: from the original). Presence-keys, value always True.
+    no_trans: dict[str, bool] = {}
+    #: Languages this article is available in (besides its primary
+    #: language). Presence-keys, value always True — the availability
+    #: index for rendering, language selection and hreflang alternates;
+    #: maintained by whoever writes translation data (docs/migrate.md).
+    langs: dict[str, bool] = {}
     #: Raw HTML for the header banner (img, styled div, canvas+script...),
     #: rendered after the banner design's artwork so author code always
     #: wins over the design's own styles.
@@ -78,6 +101,28 @@ class Data(msgspec.Struct):
     #: linked as <link rel="icon"> on every page. Empty = the build's
     #: /favicon.ico.
     favicon: str = ""
+    #: All original-language page text, content-addressed:
+    #: chunk_key -> Markdown chunk. Shared by every article.
+    chunks: dict[str, str] = {}
+    #: Machine translations: f"{chunk_hash}:{lang}" -> translated
+    #: Markdown. Also used for node titles (hash of the title text).
+    trans: dict[str, str] = {}
+    #: User override patches per article and language:
+    #: f"{path}:{lang}" -> ordered patches (paths without leading slash).
+    patches: dict[str, list[Patch]] = {}
+
+
+def node_markdown(data: Data, node: Node) -> str | None:
+    """The node's original Markdown assembled from the chunk store.
+
+    None for category labels (chunks is None); an empty page gives "".
+    Hashes missing from the store (shouldn't happen) are skipped.
+    """
+    if node.chunks is None:
+        return None
+    return join_chunks(
+        [t for h in node.chunks if (t := data.chunks.get(h)) is not None]
+    )
 
 
 def prettify(slug: str) -> str: