diff --git a/topology_api/queries/snapshot_queries.py b/topology_api/queries/snapshot_queries.py
index a6c6604..f8c2207 100644
--- a/topology_api/queries/snapshot_queries.py
+++ b/topology_api/queries/snapshot_queries.py
@@ -3,6 +3,11 @@
 from topology_api.db import read_cursor
 
 
+def _require_presentation(condition, message):
+    if not condition:
+        raise RuntimeError(f"presentation_config_error: {message}")
+
+
 def fetch_missions(base_code):
     """Return missions for a base with their latest recorded event."""
     with read_cursor() as cur:
@@ -249,6 +254,10 @@ def fetch_layout():
                 dl.name AS layout_name,
                 dl.canvas_width,
                 dl.canvas_height,
+                COALESCE(layout_theme.id, default_theme.id) AS theme_id,
+                COALESCE(layout_theme.theme_key, default_theme.theme_key) AS theme_key,
+                COALESCE(layout_theme.name, default_theme.name) AS theme_name,
+                COALESCE(layout_theme.tokens, default_theme.tokens) AS theme_tokens,
                 dn.node_key,
                 dn.component_id,
                 c.component_key,
@@ -269,12 +278,18 @@ def fetch_layout():
                     ON member_component.id = member.component_id
                 WHERE member.diagram_node_id = dn.id
             ) members ON true
+            LEFT JOIN diagram_themes layout_theme
+                ON layout_theme.id = dl.theme_id
+            LEFT JOIN diagram_themes default_theme
+                ON default_theme.base_id = dl.base_id
+               AND default_theme.is_default = true
             WHERE dl.base_id = (SELECT id FROM bases WHERE code = 'guanghan')
               AND dl.is_default = true
             ORDER BY dn.z_index, dn.node_key
         """)
         nodes = []
         layout_info = None
+        theme_info = None
         for row in cur.fetchall():
             if layout_info is None:
                 layout_info = {
@@ -282,6 +297,13 @@ def fetch_layout():
                     "name": row["layout_name"],
                     "canvasWidth": float(row["canvas_width"]),
                     "canvasHeight": float(row["canvas_height"]),
+                    "themeKey": row["theme_key"],
+                }
+                theme_info = {
+                    "id": row["theme_id"],
+                    "key": row["theme_key"],
+                    "name": row["theme_name"],
+                    "tokens": row["theme_tokens"] or {},
                 }
             nodes.append({
                 "nodeKey": row["node_key"],
@@ -298,4 +320,111 @@ def fetch_layout():
                 "decorations": row["decorations"] or {},
                 "memberKeys": row["member_keys"] or [],
             })
-        return {"layout": layout_info, "nodes": nodes} if layout_info else None
+        if layout_info is None:
+            return None
+
+        _require_presentation(theme_info and theme_info["id"], "default theme missing")
+        theme_id_val = theme_info["id"]
+
+        cur.execute("""
+            SELECT style_key, display_name, fill_color, stroke_color,
+                   stroke_width, corner_radius, title_color, meta_color,
+                   hint_color
+            FROM diagram_node_styles
+            WHERE theme_id = %(theme)s
+            ORDER BY style_key
+        """, {"theme": theme_id_val})
+        node_styles = {
+            row["style_key"]: {
+                "displayName": row["display_name"],
+                "fillColor": row["fill_color"],
+                "strokeColor": row["stroke_color"],
+                "strokeWidth": float(row["stroke_width"]),
+                "cornerRadius": float(row["corner_radius"]),
+                "titleColor": row["title_color"],
+                "metaColor": row["meta_color"],
+                "hintColor": row["hint_color"],
+            }
+            for row in cur.fetchall()
+        }
+
+        cur.execute("""
+            SELECT connection_type, display_name, stroke_color, stroke_width,
+                   dash_array, line_cap, legend_group
+            FROM diagram_edge_styles
+            WHERE theme_id = %(theme)s
+            ORDER BY connection_type
+        """, {"theme": theme_id_val})
+        edge_styles = {
+            row["connection_type"]: {
+                "displayName": row["display_name"],
+                "strokeColor": row["stroke_color"],
+                "strokeWidth": float(row["stroke_width"]),
+                "dashArray": row["dash_array"],
+                "lineCap": row["line_cap"],
+                "legendGroup": row["legend_group"],
+            }
+            for row in cur.fetchall()
+        }
+
+        cur.execute("""
+            SELECT decoration_key, display_name, fill_color, stroke_color,
+                   stroke_width, label, label_color, render_params
+            FROM diagram_decoration_styles
+            WHERE theme_id = %(theme)s
+            ORDER BY decoration_key
+        """, {"theme": theme_id_val})
+        decoration_styles = {
+            row["decoration_key"]: {
+                "displayName": row["display_name"],
+                "fillColor": row["fill_color"],
+                "strokeColor": row["stroke_color"],
+                "strokeWidth": float(row["stroke_width"]),
+                "label": row["label"],
+                "labelColor": row["label_color"],
+                "renderParams": row["render_params"] or {},
+            }
+            for row in cur.fetchall()
+        }
+
+        cur.execute("""
+            SELECT legend_key, label, item_type, style_ref, display_order
+            FROM diagram_legend_items
+            WHERE theme_id = %(theme)s
+              AND is_visible = true
+            ORDER BY display_order, legend_key
+        """, {"theme": theme_id_val})
+        legend_items = [
+            {
+                "key": row["legend_key"],
+                "label": row["label"],
+                "itemType": row["item_type"],
+                "styleRef": row["style_ref"],
+                "displayOrder": row["display_order"],
+            }
+            for row in cur.fetchall()
+        ]
+
+        missing_node_styles = {
+            node["styleKey"] for node in nodes
+        } - set(node_styles)
+        _require_presentation(
+            not missing_node_styles,
+            f"missing node styles: {sorted(missing_node_styles)}",
+        )
+
+        return {
+            "layout": layout_info,
+            "nodes": nodes,
+            "presentation": {
+                "theme": {
+                    "key": theme_info["key"],
+                    "name": theme_info["name"],
+                    "tokens": theme_info["tokens"],
+                },
+                "nodeStyles": node_styles,
+                "edgeStyles": edge_styles,
+                "decorationStyles": decoration_styles,
+                "legendItems": legend_items,
+            },
+        }