diff --git a/lib/layer-types.ts b/lib/layer-types.ts
index be6a203..6228d1c 100644
--- a/lib/layer-types.ts
+++ b/lib/layer-types.ts
@@ -79,6 +79,10 @@ export interface Layer {
 	visible: boolean;
 	/** Created timestamp */
 	createdAt: number;
+	/** If set, this layer shows data from another space (cross-space layer). */
+	spaceSlug?: string;
+	/** Resolved permission level in the source space (for cross-space layers). */
+	spaceRole?: 'viewer' | 'member' | 'moderator' | 'admin';
 }
 
 // ── Inter-layer flow ──
diff --git a/modules/rbooks/mod.ts b/modules/rbooks/mod.ts
index 0477800..aa4d348 100644
--- a/modules/rbooks/mod.ts
+++ b/modules/rbooks/mod.ts
@@ -104,12 +104,13 @@ const routes = new Hono();
 // ── API: List books ──
 routes.get("/api/books", async (c) => {
 	const space = c.req.param("space") || "global";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const search = c.req.query("search")?.toLowerCase();
 	const tag = c.req.query("tag");
 	const limit = Math.min(parseInt(c.req.query("limit") || "50"), 100);
 	const offset = parseInt(c.req.query("offset") || "0");
 
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 	let books = Object.values(doc.items).filter((b) => b.status === "published");
 
 	if (search) {
@@ -156,6 +157,7 @@ routes.get("/api/books", async (c) => {
 // ── API: Upload book ──
 routes.post("/api/books", async (c) => {
 	const space = c.req.param("space") || "global";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const token = extractToken(c.req.raw.headers);
 	if (!token) return c.json({ error: "Authentication required" }, 401);
 
@@ -187,7 +189,7 @@ routes.post("/api/books", async (c) => {
 	let slug = slugify(title);
 
 	// Check slug collision
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 	const slugExists = Object.values(doc.items).some((b) => b.slug === slug);
 	if (slugExists) {
 		slug = `${slug}-${shortId}`;
@@ -203,7 +205,7 @@ routes.post("/api/books", async (c) => {
 	const now = Date.now();
 
 	// Insert into Automerge doc
-	const docId = booksCatalogDocId(space);
+	const docId = booksCatalogDocId(dataSpace);
 	_syncServer!.changeDoc<BooksCatalogDoc>(docId, `add book: ${slug}`, (d) => {
 		d.items[id] = {
 			id,
@@ -242,9 +244,10 @@ routes.post("/api/books", async (c) => {
 // ── API: Get book details ──
 routes.get("/api/books/:id", async (c) => {
 	const space = c.req.param("space") || "global";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 	const book = findBook(doc, id);
 
 	if (!book || book.status !== "published") {
@@ -252,7 +255,7 @@ routes.get("/api/books/:id", async (c) => {
 	}
 
 	// Increment view count
-	const docId = booksCatalogDocId(space);
+	const docId = booksCatalogDocId(dataSpace);
 	_syncServer!.changeDoc<BooksCatalogDoc>(docId, `view: ${book.slug}`, (d) => {
 		if (d.items[book.id]) {
 			d.items[book.id].viewCount += 1;
@@ -266,9 +269,10 @@ routes.get("/api/books/:id", async (c) => {
 // ── API: Serve PDF ──
 routes.get("/api/books/:id/pdf", async (c) => {
 	const space = c.req.param("space") || "global";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 	const book = findBook(doc, id);
 
 	if (!book || book.status !== "published") {
@@ -283,7 +287,7 @@ routes.get("/api/books/:id/pdf", async (c) => {
 	}
 
 	// Increment download count
-	const docId = booksCatalogDocId(space);
+	const docId = booksCatalogDocId(dataSpace);
 	_syncServer!.changeDoc<BooksCatalogDoc>(docId, `download: ${book.slug}`, (d) => {
 		if (d.items[book.id]) {
 			d.items[book.id].downloadCount += 1;
@@ -303,6 +307,7 @@ routes.get("/api/books/:id/pdf", async (c) => {
 // ── Page: Library ──
 routes.get("/", (c) => {
 	const spaceSlug = c.req.param("space") || "personal";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	return c.html(renderShell({
 		title: `${spaceSlug} — Library | rSpace`,
 		moduleId: "rbooks",
@@ -318,9 +323,10 @@ routes.get("/", (c) => {
 // ── Page: Book reader ──
 routes.get("/read/:id", async (c) => {
 	const spaceSlug = c.req.param("space") || "personal";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	const id = c.req.param("id");
 
-	const doc = ensureDoc(spaceSlug);
+	const doc = ensureDoc(dataSpace);
 	const book = findBook(doc, id);
 
 	if (!book || book.status !== "published") {
@@ -335,7 +341,7 @@ routes.get("/read/:id", async (c) => {
 	}
 
 	// Increment view count
-	const docId = booksCatalogDocId(spaceSlug);
+	const docId = booksCatalogDocId(dataSpace);
 	_syncServer!.changeDoc<BooksCatalogDoc>(docId, `view: ${book.slug}`, (d) => {
 		if (d.items[book.id]) {
 			d.items[book.id].viewCount += 1;
diff --git a/modules/rcal/mod.ts b/modules/rcal/mod.ts
index 803ac43..9adeaf5 100644
--- a/modules/rcal/mod.ts
+++ b/modules/rcal/mod.ts
@@ -259,9 +259,10 @@ function seedDemoIfEmpty(space: string) {
 // GET /api/events — query events with filters
 routes.get("/api/events", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const { start, end, source, search, rTool, rEntityId, upcoming } = c.req.query();
 
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 	let events = Object.values(doc.events);
 
 	// Apply filters
@@ -311,14 +312,15 @@ routes.post("/api/events", async (c) => {
 	try { claims = await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
 
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const body = await c.req.json();
 	const { title, description, start_time, end_time, all_day, timezone, source_id, location_id, location_name,
 		is_virtual, virtual_url, virtual_platform, r_tool_source, r_tool_entity_id,
 		is_scheduled_item, provenance, item_preview } = body;
 	if (!title?.trim() || !start_time) return c.json({ error: "Title and start_time required" }, 400);
 
-	const docId = calendarDocId(space);
-	ensureDoc(space);
+	const docId = calendarDocId(dataSpace);
+	ensureDoc(dataSpace);
 	const eventId = crypto.randomUUID();
 	const now = Date.now();
 
@@ -394,9 +396,10 @@ routes.post("/api/events", async (c) => {
 // GET /api/events/scheduled — query only scheduled knowledge items
 routes.get("/api/events/scheduled", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const { date, upcoming, pending_only } = c.req.query();
 
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 	let events = Object.values(doc.events).filter((e) => {
 		const meta = e.metadata as ScheduledItemMetadata | null;
 		return meta?.isScheduledItem === true;
@@ -429,8 +432,9 @@ routes.get("/api/events/scheduled", async (c) => {
 // GET /api/events/:id
 routes.get("/api/events/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 
 	const ev = doc.events[id];
 	if (!ev) return c.json({ error: "Event not found" }, 404);
@@ -445,11 +449,12 @@ routes.patch("/api/events/:id", async (c) => {
 	try { claims = await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
 
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	const body = await c.req.json();
 
-	const docId = calendarDocId(space);
-	const doc = ensureDoc(space);
+	const docId = calendarDocId(dataSpace);
+	const doc = ensureDoc(dataSpace);
 	if (!doc.events[id]) return c.json({ error: "Not found" }, 404);
 
 	// Map of allowed body keys to CalendarEvent fields
@@ -497,10 +502,11 @@ routes.patch("/api/events/:id", async (c) => {
 // DELETE /api/events/:id
 routes.delete("/api/events/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 
-	const docId = calendarDocId(space);
-	const doc = ensureDoc(space);
+	const docId = calendarDocId(dataSpace);
+	const doc = ensureDoc(dataSpace);
 	if (!doc.events[id]) return c.json({ error: "Not found" }, 404);
 
 	_syncServer!.changeDoc<CalendarDoc>(docId, `delete event ${id}`, (d) => {
@@ -513,8 +519,9 @@ routes.delete("/api/events/:id", async (c) => {
 
 routes.get("/api/sources", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const { is_active, is_visible, source_type } = c.req.query();
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 
 	let sources = Object.values(doc.sources);
 
@@ -541,9 +548,10 @@ routes.post("/api/sources", async (c) => {
 	try { await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
 
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const body = await c.req.json();
-	const docId = calendarDocId(space);
-	ensureDoc(space);
+	const docId = calendarDocId(dataSpace);
+	ensureDoc(dataSpace);
 
 	const sourceId = crypto.randomUUID();
 	const now = Date.now();
@@ -601,8 +609,9 @@ function deriveLocations(doc: CalendarDoc): DerivedLocation[] {
 
 routes.get("/api/locations", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const { granularity, parent, search, root } = c.req.query();
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 
 	let locations = deriveLocations(doc);
 
@@ -627,7 +636,8 @@ routes.get("/api/locations", async (c) => {
 
 routes.get("/api/locations/tree", async (c) => {
 	const space = c.req.param("space") || "demo";
-	const doc = ensureDoc(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const doc = ensureDoc(dataSpace);
 
 	// Flat list with depth=0 since hierarchical parent_id data is not stored in Automerge
 	const locations = deriveLocations(doc).map((l) => ({ ...l, depth: 0 }));
@@ -678,7 +688,8 @@ routes.get("/api/lunar", async (c) => {
 
 routes.get("/api/stats", async (c) => {
 	const space = c.req.param("space") || "demo";
-	const doc = ensureDoc(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const doc = ensureDoc(dataSpace);
 
 	const events = Object.values(doc.events).length;
 	const sources = Object.values(doc.sources).filter((s) => s.isActive).length;
@@ -691,11 +702,12 @@ routes.get("/api/stats", async (c) => {
 
 routes.get("/api/context/:tool", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const tool = c.req.param("tool");
 	const entityId = c.req.query("entityId");
 	if (!entityId) return c.json({ error: "entityId required" }, 400);
 
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 	const matching = Object.values(doc.events)
 		.filter((e) => e.rToolSource === tool && e.rToolEntityId === entityId)
 		.sort((a, b) => a.startTime - b.startTime);
@@ -707,6 +719,7 @@ routes.get("/api/context/:tool", async (c) => {
 // ── Page route ──
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `${space} — Calendar | rSpace`,
 		moduleId: "rcal",
diff --git a/modules/rdata/mod.ts b/modules/rdata/mod.ts
index da12662..41aade6 100644
--- a/modules/rdata/mod.ts
+++ b/modules/rdata/mod.ts
@@ -121,6 +121,7 @@ routes.post("/api/collect", async (c) => {
 // ── Page route ──
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `${space} — Data | rSpace`,
 		moduleId: "rdata",
diff --git a/modules/rdesign/mod.ts b/modules/rdesign/mod.ts
index d385218..f1c30fc 100644
--- a/modules/rdesign/mod.ts
+++ b/modules/rdesign/mod.ts
@@ -19,6 +19,7 @@ routes.get("/api/health", (c) => {
 
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const view = c.req.query("view");
 
 	if (view === "demo") {
diff --git a/modules/rdocs/mod.ts b/modules/rdocs/mod.ts
index e7d0605..2fc0575 100644
--- a/modules/rdocs/mod.ts
+++ b/modules/rdocs/mod.ts
@@ -19,6 +19,7 @@ routes.get("/api/health", (c) => {
 
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const view = c.req.query("view");
 
 	if (view === "demo") {
diff --git a/modules/rmaps/mod.ts b/modules/rmaps/mod.ts
index 06ab2f1..8b672fe 100644
--- a/modules/rmaps/mod.ts
+++ b/modules/rmaps/mod.ts
@@ -134,6 +134,7 @@ routes.get("/api/c3nav/:event", async (c) => {
 // ── Page route ──
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `${space} — Maps | rSpace`,
 		moduleId: "rmaps",
@@ -149,6 +150,7 @@ routes.get("/", (c) => {
 // Room-specific page
 routes.get("/:room", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const room = c.req.param("room");
 	return c.html(renderShell({
 		title: `${room} — Maps | rSpace`,
diff --git a/modules/rnetwork/mod.ts b/modules/rnetwork/mod.ts
index a0830c0..888f409 100644
--- a/modules/rnetwork/mod.ts
+++ b/modules/rnetwork/mod.ts
@@ -55,14 +55,16 @@ const CACHE_TTL = 60_000;
 // ── API: Health ──
 routes.get("/api/health", (c) => {
 	const space = c.req.param("space") || "demo";
-	const token = getTokenForSpace(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const token = getTokenForSpace(dataSpace);
 	return c.json({ ok: true, module: "network", space, twentyConfigured: !!token });
 });
 
 // ── API: Info ──
 routes.get("/api/info", (c) => {
 	const space = c.req.param("space") || "demo";
-	const token = getTokenForSpace(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const token = getTokenForSpace(dataSpace);
 	return c.json({
 		module: "network",
 		description: "Community relationship graph visualization",
@@ -76,7 +78,8 @@ routes.get("/api/info", (c) => {
 // ── API: People ──
 routes.get("/api/people", async (c) => {
 	const space = c.req.param("space") || "demo";
-	const token = getTokenForSpace(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const token = getTokenForSpace(dataSpace);
 	const data = await twentyQuery(`{
 		people(first: 200) {
 			edges {
@@ -91,7 +94,7 @@ routes.get("/api/people", async (c) => {
 				}
 			}
 		}
-	}`, undefined, space);
+	}`, undefined, dataSpace);
 	if (!data) return c.json({ people: [], error: token ? "Twenty API error" : "Twenty not configured" });
 	const people = ((data as any).people?.edges || []).map((e: any) => e.node);
 	c.header("Cache-Control", "public, max-age=60");
@@ -101,7 +104,8 @@ routes.get("/api/people", async (c) => {
 // ── API: Companies ──
 routes.get("/api/companies", async (c) => {
 	const space = c.req.param("space") || "demo";
-	const token = getTokenForSpace(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const token = getTokenForSpace(dataSpace);
 	const data = await twentyQuery(`{
 		companies(first: 200) {
 			edges {
@@ -115,7 +119,7 @@ routes.get("/api/companies", async (c) => {
 				}
 			}
 		}
-	}`, undefined, space);
+	}`, undefined, dataSpace);
 	if (!data) return c.json({ companies: [], error: token ? "Twenty API error" : "Twenty not configured" });
 	const companies = ((data as any).companies?.edges || []).map((e: any) => e.node);
 	c.header("Cache-Control", "public, max-age=60");
@@ -125,10 +129,11 @@ routes.get("/api/companies", async (c) => {
 // ── API: Graph — transform entities to node/edge format ──
 routes.get("/api/graph", async (c) => {
 	const space = c.req.param("space") || "demo";
-	const token = getTokenForSpace(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const token = getTokenForSpace(dataSpace);
 
 	// Check per-space cache
-	const cached = graphCaches.get(space);
+	const cached = graphCaches.get(dataSpace);
 	if (cached && Date.now() - cached.ts < CACHE_TTL) {
 		c.header("Cache-Control", "public, max-age=60");
 		return c.json(cached.data);
@@ -186,7 +191,7 @@ routes.get("/api/graph", async (c) => {
 					}
 				}
 			}
-		}`, undefined, space);
+		}`, undefined, dataSpace);
 
 		if (!data) return c.json({ nodes: [], edges: [], error: "Twenty API error" });
 
@@ -227,7 +232,7 @@ routes.get("/api/graph", async (c) => {
 		}
 
 		const result = { nodes, edges, demo: false };
-		graphCaches.set(space, { data: result, ts: Date.now() });
+		graphCaches.set(dataSpace, { data: result, ts: Date.now() });
 		c.header("Cache-Control", "public, max-age=60");
 		return c.json(result);
 	} catch (e) {
@@ -246,7 +251,8 @@ routes.get("/api/workspaces", (c) => {
 // ── API: Opportunities ──
 routes.get("/api/opportunities", async (c) => {
 	const space = c.req.param("space") || "demo";
-	const token = getTokenForSpace(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const token = getTokenForSpace(dataSpace);
 	const data = await twentyQuery(`{
 		opportunities(first: 200) {
 			edges {
@@ -262,7 +268,7 @@ routes.get("/api/opportunities", async (c) => {
 				}
 			}
 		}
-	}`, undefined, space);
+	}`, undefined, dataSpace);
 	if (!data) return c.json({ opportunities: [], error: token ? "Twenty API error" : "Twenty not configured" });
 	const opportunities = ((data as any).opportunities?.edges || []).map((e: any) => e.node);
 	c.header("Cache-Control", "public, max-age=60");
@@ -272,6 +278,7 @@ routes.get("/api/opportunities", async (c) => {
 // ── CRM sub-route — embed Twenty CRM via iframe ──
 routes.get("/crm", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderExternalAppShell({
 		title: `${space} — CRM | rSpace`,
 		moduleId: "rnetwork",
@@ -285,6 +292,7 @@ routes.get("/crm", (c) => {
 // ── Page route ──
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const view = c.req.query("view");
 
 	if (view === "app") {
diff --git a/modules/rnotes/mod.ts b/modules/rnotes/mod.ts
index 584a074..aa08a40 100644
--- a/modules/rnotes/mod.ts
+++ b/modules/rnotes/mod.ts
@@ -245,8 +245,9 @@ function extractPlainText(content: string, format?: string): string {
 // GET /api/notebooks — list notebooks
 routes.get("/api/notebooks", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 
-	const notebooks = listNotebooks(space).map(({ doc }) => notebookToRest(doc));
+	const notebooks = listNotebooks(dataSpace).map(({ doc }) => notebookToRest(doc));
 	notebooks.sort((a, b) => new Date(b.updated_at).getTime() - new Date(a.updated_at).getTime());
 	return c.json({ notebooks, source: "automerge" });
 });
@@ -254,6 +255,7 @@ routes.get("/api/notebooks", async (c) => {
 // POST /api/notebooks — create notebook
 routes.post("/api/notebooks", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const token = extractToken(c.req.raw.headers);
 	if (!token) return c.json({ error: "Authentication required" }, 401);
 	let claims;
@@ -266,8 +268,8 @@ routes.post("/api/notebooks", async (c) => {
 	const notebookId = newId();
 	const now = Date.now();
 
-	const doc = ensureDoc(space, notebookId);
-	_syncServer!.changeDoc<NotebookDoc>(notebookDocId(space, notebookId), "Create notebook", (d) => {
+	const doc = ensureDoc(dataSpace, notebookId);
+	_syncServer!.changeDoc<NotebookDoc>(notebookDocId(dataSpace, notebookId), "Create notebook", (d) => {
 		d.notebook.id = notebookId;
 		d.notebook.title = nbTitle;
 		d.notebook.slug = slugify(nbTitle);
@@ -278,16 +280,17 @@ routes.post("/api/notebooks", async (c) => {
 		d.notebook.updatedAt = now;
 	});
 
-	const updatedDoc = _syncServer!.getDoc<NotebookDoc>(notebookDocId(space, notebookId))!;
+	const updatedDoc = _syncServer!.getDoc<NotebookDoc>(notebookDocId(dataSpace, notebookId))!;
 	return c.json(notebookToRest(updatedDoc), 201);
 });
 
 // GET /api/notebooks/:id — notebook detail with notes
 routes.get("/api/notebooks/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 
-	const docId = notebookDocId(space, id);
+	const docId = notebookDocId(dataSpace, id);
 	const doc = _syncServer?.getDoc<NotebookDoc>(docId);
 	if (!doc || !doc.notebook || !doc.notebook.title) {
 		return c.json({ error: "Notebook not found" }, 404);
@@ -306,6 +309,7 @@ routes.get("/api/notebooks/:id", async (c) => {
 // PUT /api/notebooks/:id — update notebook
 routes.put("/api/notebooks/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const token = extractToken(c.req.raw.headers);
 	if (!token) return c.json({ error: "Authentication required" }, 401);
 	let claims;
@@ -319,7 +323,7 @@ routes.put("/api/notebooks/:id", async (c) => {
 		return c.json({ error: "No fields to update" }, 400);
 	}
 
-	const docId = notebookDocId(space, id);
+	const docId = notebookDocId(dataSpace, id);
 	const doc = _syncServer?.getDoc<NotebookDoc>(docId);
 	if (!doc || !doc.notebook || !doc.notebook.title) {
 		return c.json({ error: "Notebook not found" }, 404);
@@ -340,9 +344,10 @@ routes.put("/api/notebooks/:id", async (c) => {
 // DELETE /api/notebooks/:id
 routes.delete("/api/notebooks/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 
-	const docId = notebookDocId(space, id);
+	const docId = notebookDocId(dataSpace, id);
 	const doc = _syncServer?.getDoc<NotebookDoc>(docId);
 	if (!doc || !doc.notebook || !doc.notebook.title) {
 		return c.json({ error: "Notebook not found" }, 404);
@@ -366,15 +371,16 @@ routes.delete("/api/notebooks/:id", async (c) => {
 // GET /api/notes — list all notes
 routes.get("/api/notes", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const { notebook_id, type, q, limit = "50", offset = "0" } = c.req.query();
 
 	let allNotes: ReturnType<typeof noteToRest>[] = [];
 	const notebooks = notebook_id
 		? (() => {
-			const doc = _syncServer?.getDoc<NotebookDoc>(notebookDocId(space, notebook_id));
+			const doc = _syncServer?.getDoc<NotebookDoc>(notebookDocId(dataSpace, notebook_id));
 			return doc ? [{ doc }] : [];
 		})()
-		: listNotebooks(space);
+		: listNotebooks(dataSpace);
 
 	for (const { doc } of notebooks) {
 		for (const item of Object.values(doc.items)) {
@@ -401,6 +407,7 @@ routes.get("/api/notes", async (c) => {
 // POST /api/notes — create note
 routes.post("/api/notes", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const token = extractToken(c.req.raw.headers);
 	if (!token) return c.json({ error: "Authentication required" }, 401);
 	let claims;
@@ -439,8 +446,8 @@ routes.post("/api/notes", async (c) => {
 	});
 
 	// Ensure the notebook doc exists, then add the note
-	ensureDoc(space, notebook_id);
-	const docId = notebookDocId(space, notebook_id);
+	ensureDoc(dataSpace, notebook_id);
+	const docId = notebookDocId(dataSpace, notebook_id);
 	_syncServer!.changeDoc<NotebookDoc>(docId, `Create note: ${title.trim()}`, (d) => {
 		d.items[noteId] = item;
 		d.notebook.updatedAt = Date.now();
@@ -452,9 +459,10 @@ routes.post("/api/notes", async (c) => {
 // GET /api/notes/:id — note detail
 routes.get("/api/notes/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 
-	const found = findNote(space, id);
+	const found = findNote(dataSpace, id);
 	if (!found) return c.json({ error: "Note not found" }, 404);
 
 	return c.json({ ...noteToRest(found.item), source: "automerge" });
@@ -463,6 +471,7 @@ routes.get("/api/notes/:id", async (c) => {
 // PUT /api/notes/:id — update note
 routes.put("/api/notes/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	const body = await c.req.json();
 	const { title, content, content_format, type, url, language, is_pinned, sort_order } = body;
@@ -472,7 +481,7 @@ routes.put("/api/notes/:id", async (c) => {
 		return c.json({ error: "No fields to update" }, 400);
 	}
 
-	const found = findNote(space, id);
+	const found = findNote(dataSpace, id);
 	if (!found) return c.json({ error: "Note not found" }, 404);
 
 	const contentPlain = content !== undefined
@@ -503,9 +512,10 @@ routes.put("/api/notes/:id", async (c) => {
 // DELETE /api/notes/:id
 routes.delete("/api/notes/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 
-	const found = findNote(space, id);
+	const found = findNote(dataSpace, id);
 	if (!found) return c.json({ error: "Note not found" }, 404);
 
 	_syncServer!.changeDoc<NotebookDoc>(found.docId, `Delete note ${id}`, (d) => {
@@ -586,6 +596,7 @@ function getConnectionDoc(space: string): ConnectionsDoc | null {
 // POST /api/import/upload — ZIP upload for Logseq/Obsidian
 routes.post("/api/import/upload", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const token = extractToken(c.req.raw.headers);
 	if (!token) return c.json({ error: "Authentication required" }, 401);
 	try { await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
@@ -612,8 +623,8 @@ routes.post("/api/import/upload", async (c) => {
 		// Create a new notebook with the import title
 		targetNotebookId = newId();
 		const now = Date.now();
-		ensureDoc(space, targetNotebookId);
-		_syncServer!.changeDoc<NotebookDoc>(notebookDocId(space, targetNotebookId), "Create import notebook", (d) => {
+		ensureDoc(dataSpace, targetNotebookId);
+		_syncServer!.changeDoc<NotebookDoc>(notebookDocId(dataSpace, targetNotebookId), "Create import notebook", (d) => {
 			d.notebook.id = targetNotebookId!;
 			d.notebook.title = result.notebookTitle;
 			d.notebook.slug = slugify(result.notebookTitle);
@@ -622,7 +633,7 @@ routes.post("/api/import/upload", async (c) => {
 		});
 	}
 
-	const { imported, updated } = importNotesIntoNotebook(space, targetNotebookId, result.notes);
+	const { imported, updated } = importNotesIntoNotebook(dataSpace, targetNotebookId, result.notes);
 
 	return c.json({
 		ok: true,
@@ -637,6 +648,7 @@ routes.post("/api/import/upload", async (c) => {
 // POST /api/import/notion — Import selected Notion pages
 routes.post("/api/import/notion", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const token = extractToken(c.req.raw.headers);
 	if (!token) return c.json({ error: "Authentication required" }, 401);
 	try { await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
@@ -648,7 +660,7 @@ routes.post("/api/import/notion", async (c) => {
 		return c.json({ error: "pageIds array is required" }, 400);
 	}
 
-	const conn = getConnectionDoc(space);
+	const conn = getConnectionDoc(dataSpace);
 	if (!conn?.notion?.accessToken) {
 		return c.json({ error: "Notion not connected. Connect your Notion account first." }, 400);
 	}
@@ -664,8 +676,8 @@ routes.post("/api/import/notion", async (c) => {
 	if (!targetNotebookId) {
 		targetNotebookId = newId();
 		const now = Date.now();
-		ensureDoc(space, targetNotebookId);
-		_syncServer!.changeDoc<NotebookDoc>(notebookDocId(space, targetNotebookId), "Create Notion import notebook", (d) => {
+		ensureDoc(dataSpace, targetNotebookId);
+		_syncServer!.changeDoc<NotebookDoc>(notebookDocId(dataSpace, targetNotebookId), "Create Notion import notebook", (d) => {
 			d.notebook.id = targetNotebookId!;
 			d.notebook.title = result.notebookTitle;
 			d.notebook.slug = slugify(result.notebookTitle);
@@ -674,7 +686,7 @@ routes.post("/api/import/notion", async (c) => {
 		});
 	}
 
-	const { imported, updated } = importNotesIntoNotebook(space, targetNotebookId, result.notes);
+	const { imported, updated } = importNotesIntoNotebook(dataSpace, targetNotebookId, result.notes);
 
 	return c.json({ ok: true, notebookId: targetNotebookId, imported, updated, warnings: result.warnings });
 });
@@ -682,6 +694,7 @@ routes.post("/api/import/notion", async (c) => {
 // POST /api/import/google-docs — Import selected Google Docs
 routes.post("/api/import/google-docs", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const token = extractToken(c.req.raw.headers);
 	if (!token) return c.json({ error: "Authentication required" }, 401);
 	try { await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
@@ -693,7 +706,7 @@ routes.post("/api/import/google-docs", async (c) => {
 		return c.json({ error: "docIds array is required" }, 400);
 	}
 
-	const conn = getConnectionDoc(space);
+	const conn = getConnectionDoc(dataSpace);
 	if (!conn?.google?.accessToken) {
 		return c.json({ error: "Google not connected. Connect your Google account first." }, 400);
 	}
@@ -708,8 +721,8 @@ routes.post("/api/import/google-docs", async (c) => {
 	if (!targetNotebookId) {
 		targetNotebookId = newId();
 		const now = Date.now();
-		ensureDoc(space, targetNotebookId);
-		_syncServer!.changeDoc<NotebookDoc>(notebookDocId(space, targetNotebookId), "Create Google Docs import notebook", (d) => {
+		ensureDoc(dataSpace, targetNotebookId);
+		_syncServer!.changeDoc<NotebookDoc>(notebookDocId(dataSpace, targetNotebookId), "Create Google Docs import notebook", (d) => {
 			d.notebook.id = targetNotebookId!;
 			d.notebook.title = result.notebookTitle;
 			d.notebook.slug = slugify(result.notebookTitle);
@@ -718,7 +731,7 @@ routes.post("/api/import/google-docs", async (c) => {
 		});
 	}
 
-	const { imported, updated } = importNotesIntoNotebook(space, targetNotebookId, result.notes);
+	const { imported, updated } = importNotesIntoNotebook(dataSpace, targetNotebookId, result.notes);
 
 	return c.json({ ok: true, notebookId: targetNotebookId, imported, updated, warnings: result.warnings });
 });
@@ -726,7 +739,8 @@ routes.post("/api/import/google-docs", async (c) => {
 // GET /api/import/notion/pages — Browse Notion pages for selection
 routes.get("/api/import/notion/pages", async (c) => {
 	const space = c.req.param("space") || "demo";
-	const conn = getConnectionDoc(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const conn = getConnectionDoc(dataSpace);
 	if (!conn?.notion?.accessToken) {
 		return c.json({ error: "Notion not connected" }, 400);
 	}
@@ -768,7 +782,8 @@ routes.get("/api/import/notion/pages", async (c) => {
 // GET /api/import/google-docs/list — Browse Google Docs for selection
 routes.get("/api/import/google-docs/list", async (c) => {
 	const space = c.req.param("space") || "demo";
-	const conn = getConnectionDoc(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const conn = getConnectionDoc(dataSpace);
 	if (!conn?.google?.accessToken) {
 		return c.json({ error: "Google not connected" }, 400);
 	}
@@ -798,10 +813,11 @@ routes.get("/api/import/google-docs/list", async (c) => {
 // GET /api/export/obsidian — Download Obsidian-format ZIP
 routes.get("/api/export/obsidian", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const notebookId = c.req.query("notebookId");
 	if (!notebookId) return c.json({ error: "notebookId is required" }, 400);
 
-	const docId = notebookDocId(space, notebookId);
+	const docId = notebookDocId(dataSpace, notebookId);
 	const doc = _syncServer?.getDoc<NotebookDoc>(docId);
 	if (!doc || !doc.notebook?.title) return c.json({ error: "Notebook not found" }, 404);
 
@@ -820,10 +836,11 @@ routes.get("/api/export/obsidian", async (c) => {
 // GET /api/export/logseq — Download Logseq-format ZIP
 routes.get("/api/export/logseq", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const notebookId = c.req.query("notebookId");
 	if (!notebookId) return c.json({ error: "notebookId is required" }, 400);
 
-	const docId = notebookDocId(space, notebookId);
+	const docId = notebookDocId(dataSpace, notebookId);
 	const doc = _syncServer?.getDoc<NotebookDoc>(docId);
 	if (!doc || !doc.notebook?.title) return c.json({ error: "Notebook not found" }, 404);
 
@@ -842,6 +859,7 @@ routes.get("/api/export/logseq", async (c) => {
 // GET /api/export/markdown — Download universal Markdown ZIP
 routes.get("/api/export/markdown", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const notebookId = c.req.query("notebookId");
 	const noteIds = c.req.query("noteIds");
 
@@ -849,7 +867,7 @@ routes.get("/api/export/markdown", async (c) => {
 	let title = "rNotes Export";
 
 	if (notebookId) {
-		const docId = notebookDocId(space, notebookId);
+		const docId = notebookDocId(dataSpace, notebookId);
 		const doc = _syncServer?.getDoc<NotebookDoc>(docId);
 		if (!doc || !doc.notebook?.title) return c.json({ error: "Notebook not found" }, 404);
 		notes = Object.values(doc.items);
@@ -857,7 +875,7 @@ routes.get("/api/export/markdown", async (c) => {
 	} else if (noteIds) {
 		const ids = noteIds.split(",").map(id => id.trim());
 		for (const id of ids) {
-			const found = findNote(space, id);
+			const found = findNote(dataSpace, id);
 			if (found) notes.push(found.item);
 		}
 	} else {
@@ -881,6 +899,7 @@ routes.get("/api/export/markdown", async (c) => {
 // POST /api/export/notion — Push notes to Notion
 routes.post("/api/export/notion", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const token = extractToken(c.req.raw.headers);
 	if (!token) return c.json({ error: "Authentication required" }, 401);
 	try { await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
@@ -888,19 +907,19 @@ routes.post("/api/export/notion", async (c) => {
 	const body = await c.req.json();
 	const { notebookId, noteIds, parentId } = body;
 
-	const conn = getConnectionDoc(space);
+	const conn = getConnectionDoc(dataSpace);
 	if (!conn?.notion?.accessToken) {
 		return c.json({ error: "Notion not connected" }, 400);
 	}
 
 	let notes: NoteItem[] = [];
 	if (notebookId) {
-		const docId = notebookDocId(space, notebookId);
+		const docId = notebookDocId(dataSpace, notebookId);
 		const doc = _syncServer?.getDoc<NotebookDoc>(docId);
 		if (doc) notes = Object.values(doc.items);
 	} else if (noteIds && Array.isArray(noteIds)) {
 		for (const id of noteIds) {
-			const found = findNote(space, id);
+			const found = findNote(dataSpace, id);
 			if (found) notes.push(found.item);
 		}
 	}
@@ -920,6 +939,7 @@ routes.post("/api/export/notion", async (c) => {
 // POST /api/export/google-docs — Push notes to Google Docs
 routes.post("/api/export/google-docs", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const token = extractToken(c.req.raw.headers);
 	if (!token) return c.json({ error: "Authentication required" }, 401);
 	try { await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
@@ -927,19 +947,19 @@ routes.post("/api/export/google-docs", async (c) => {
 	const body = await c.req.json();
 	const { notebookId, noteIds, parentId } = body;
 
-	const conn = getConnectionDoc(space);
+	const conn = getConnectionDoc(dataSpace);
 	if (!conn?.google?.accessToken) {
 		return c.json({ error: "Google not connected" }, 400);
 	}
 
 	let notes: NoteItem[] = [];
 	if (notebookId) {
-		const docId = notebookDocId(space, notebookId);
+		const docId = notebookDocId(dataSpace, notebookId);
 		const doc = _syncServer?.getDoc<NotebookDoc>(docId);
 		if (doc) notes = Object.values(doc.items);
 	} else if (noteIds && Array.isArray(noteIds)) {
 		for (const id of noteIds) {
-			const found = findNote(space, id);
+			const found = findNote(dataSpace, id);
 			if (found) notes.push(found.item);
 		}
 	}
@@ -959,7 +979,8 @@ routes.post("/api/export/google-docs", async (c) => {
 // GET /api/connections — Status of all integrations
 routes.get("/api/connections", async (c) => {
 	const space = c.req.param("space") || "demo";
-	const conn = getConnectionDoc(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const conn = getConnectionDoc(dataSpace);
 
 	return c.json({
 		notion: conn?.notion ? {
@@ -980,6 +1001,7 @@ routes.get("/api/connections", async (c) => {
 // ── Page route ──
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `${space} — Notes | rSpace`,
 		moduleId: "rnotes",
diff --git a/modules/rphotos/mod.ts b/modules/rphotos/mod.ts
index 8a59542..f013d3f 100644
--- a/modules/rphotos/mod.ts
+++ b/modules/rphotos/mod.ts
@@ -110,6 +110,7 @@ routes.get("/api/assets/:id/original", async (c) => {
 // ── Embedded Immich UI ──
 routes.get("/album", (c) => {
 	const spaceSlug = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	return c.html(renderExternalAppShell({
 		title: `${spaceSlug} — Immich | rSpace`,
 		moduleId: "rphotos",
@@ -124,6 +125,7 @@ routes.get("/album", (c) => {
 // ── Page route ──
 routes.get("/", (c) => {
 	const spaceSlug = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	return c.html(renderShell({
 		title: `${spaceSlug} — Photos | rSpace`,
 		moduleId: "rphotos",
diff --git a/modules/rpubs/mod.ts b/modules/rpubs/mod.ts
index b03c2dd..1a49236 100644
--- a/modules/rpubs/mod.ts
+++ b/modules/rpubs/mod.ts
@@ -322,6 +322,7 @@ routes.get("/api/artifact/:id/pdf", async (c) => {
 // ── Page: Editor ──
 routes.get("/", (c) => {
 	const spaceSlug = c.req.param("space") || "personal";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	return c.html(renderShell({
 		title: `${spaceSlug} — rPubs Editor | rSpace`,
 		moduleId: "rpubs",
diff --git a/modules/rschedule/mod.ts b/modules/rschedule/mod.ts
index 82a74b4..6c37a09 100644
--- a/modules/rschedule/mod.ts
+++ b/modules/rschedule/mod.ts
@@ -756,6 +756,7 @@ function seedDefaultJobs(space: string) {
 // GET / — serve schedule UI
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(
 		renderShell({
 			title: `${space} — Schedule | rSpace`,
@@ -773,7 +774,8 @@ routes.get("/", (c) => {
 // GET /api/jobs — list all jobs
 routes.get("/api/jobs", (c) => {
 	const space = c.req.param("space") || "demo";
-	const doc = ensureDoc(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const doc = ensureDoc(dataSpace);
 	const jobs = Object.values(doc.jobs).map((j) => ({
 		...j,
 		cronHuman: cronToHuman(j.cronExpression),
@@ -785,6 +787,7 @@ routes.get("/api/jobs", (c) => {
 // POST /api/jobs — create a new job
 routes.post("/api/jobs", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const body = await c.req.json();
 
 	const { name, description, cronExpression, timezone, actionType, actionConfig, enabled } = body;
@@ -798,8 +801,8 @@ routes.post("/api/jobs", async (c) => {
 		return c.json({ error: "Invalid cron expression" }, 400);
 	}
 
-	const docId = scheduleDocId(space);
-	ensureDoc(space);
+	const docId = scheduleDocId(dataSpace);
+	ensureDoc(dataSpace);
 	const jobId = crypto.randomUUID();
 	const now = Date.now();
 	const tz = timezone || "UTC";
@@ -832,8 +835,9 @@ routes.post("/api/jobs", async (c) => {
 // GET /api/jobs/:id
 routes.get("/api/jobs/:id", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 
 	const job = doc.jobs[id];
 	if (!job) return c.json({ error: "Job not found" }, 404);
@@ -843,11 +847,12 @@ routes.get("/api/jobs/:id", (c) => {
 // PUT /api/jobs/:id — update a job
 routes.put("/api/jobs/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	const body = await c.req.json();
 
-	const docId = scheduleDocId(space);
-	const doc = ensureDoc(space);
+	const docId = scheduleDocId(dataSpace);
+	const doc = ensureDoc(dataSpace);
 	if (!doc.jobs[id]) return c.json({ error: "Job not found" }, 404);
 
 	// Validate cron if provided
@@ -885,10 +890,11 @@ routes.put("/api/jobs/:id", async (c) => {
 // DELETE /api/jobs/:id
 routes.delete("/api/jobs/:id", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 
-	const docId = scheduleDocId(space);
-	const doc = ensureDoc(space);
+	const docId = scheduleDocId(dataSpace);
+	const doc = ensureDoc(dataSpace);
 	if (!doc.jobs[id]) return c.json({ error: "Job not found" }, 404);
 
 	_syncServer!.changeDoc<ScheduleDoc>(docId, `delete job ${id}`, (d) => {
@@ -901,10 +907,11 @@ routes.delete("/api/jobs/:id", (c) => {
 // POST /api/jobs/:id/run — manually trigger a job
 routes.post("/api/jobs/:id/run", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 
-	const docId = scheduleDocId(space);
-	const doc = ensureDoc(space);
+	const docId = scheduleDocId(dataSpace);
+	const doc = ensureDoc(dataSpace);
 	const job = doc.jobs[id];
 	if (!job) return c.json({ error: "Job not found" }, 404);
 
@@ -912,7 +919,7 @@ routes.post("/api/jobs/:id/run", async (c) => {
 	let result: { success: boolean; message: string };
 
 	try {
-		result = await executeJob(job, space);
+		result = await executeJob(job, dataSpace);
 	} catch (e: any) {
 		result = { success: false, message: e.message || String(e) };
 	}
@@ -947,7 +954,8 @@ routes.post("/api/jobs/:id/run", async (c) => {
 // GET /api/log — execution log
 routes.get("/api/log", (c) => {
 	const space = c.req.param("space") || "demo";
-	const doc = ensureDoc(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const doc = ensureDoc(dataSpace);
 	const log = [...doc.log].reverse(); // newest first
 	return c.json({ count: log.length, results: log });
 });
@@ -955,8 +963,9 @@ routes.get("/api/log", (c) => {
 // GET /api/log/:jobId — execution log filtered by job
 routes.get("/api/log/:jobId", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const jobId = c.req.param("jobId");
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 	const log = doc.log.filter((e) => e.jobId === jobId).reverse();
 	return c.json({ count: log.length, results: log });
 });
@@ -1103,7 +1112,8 @@ async function executeReminderEmail(
 // GET /api/reminders — list reminders
 routes.get("/api/reminders", (c) => {
 	const space = c.req.param("space") || "demo";
-	const doc = ensureDoc(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const doc = ensureDoc(dataSpace);
 
 	let reminders = Object.values(doc.reminders);
 
@@ -1131,14 +1141,15 @@ routes.get("/api/reminders", (c) => {
 // POST /api/reminders — create a reminder
 routes.post("/api/reminders", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const body = await c.req.json();
 
 	const { title, description, remindAt, allDay, timezone, notifyEmail, syncToCalendar, cronExpression } = body;
 	if (!title?.trim() || !remindAt)
 		return c.json({ error: "title and remindAt required" }, 400);
 
-	const docId = scheduleDocId(space);
-	const doc = ensureDoc(space);
+	const docId = scheduleDocId(dataSpace);
+	const doc = ensureDoc(dataSpace);
 
 	if (Object.keys(doc.reminders).length >= MAX_REMINDERS)
 		return c.json({ error: `Maximum ${MAX_REMINDERS} reminders reached` }, 400);
@@ -1169,7 +1180,7 @@ routes.post("/api/reminders", async (c) => {
 
 	// Sync to calendar if requested
 	if (syncToCalendar) {
-		const eventId = syncReminderToCalendar(reminder, space);
+		const eventId = syncReminderToCalendar(reminder, dataSpace);
 		if (eventId) reminder.calendarEventId = eventId;
 	}
 
@@ -1184,8 +1195,9 @@ routes.post("/api/reminders", async (c) => {
 // GET /api/reminders/:id — get single reminder
 routes.get("/api/reminders/:id", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
-	const doc = ensureDoc(space);
+	const doc = ensureDoc(dataSpace);
 
 	const reminder = doc.reminders[id];
 	if (!reminder) return c.json({ error: "Reminder not found" }, 404);
@@ -1195,11 +1207,12 @@ routes.get("/api/reminders/:id", (c) => {
 // PUT /api/reminders/:id — update a reminder
 routes.put("/api/reminders/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	const body = await c.req.json();
 
-	const docId = scheduleDocId(space);
-	const doc = ensureDoc(space);
+	const docId = scheduleDocId(dataSpace);
+	const doc = ensureDoc(dataSpace);
 	if (!doc.reminders[id]) return c.json({ error: "Reminder not found" }, 404);
 
 	_syncServer!.changeDoc<ScheduleDoc>(docId, `update reminder ${id}`, (d) => {
@@ -1222,16 +1235,17 @@ routes.put("/api/reminders/:id", async (c) => {
 // DELETE /api/reminders/:id — delete (cascades to calendar)
 routes.delete("/api/reminders/:id", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 
-	const docId = scheduleDocId(space);
-	const doc = ensureDoc(space);
+	const docId = scheduleDocId(dataSpace);
+	const doc = ensureDoc(dataSpace);
 	const reminder = doc.reminders[id];
 	if (!reminder) return c.json({ error: "Reminder not found" }, 404);
 
 	// Cascade: delete linked calendar event
 	if (reminder.calendarEventId) {
-		deleteCalendarEvent(space, reminder.calendarEventId);
+		deleteCalendarEvent(dataSpace, reminder.calendarEventId);
 	}
 
 	_syncServer!.changeDoc<ScheduleDoc>(docId, `delete reminder ${id}`, (d) => {
@@ -1244,10 +1258,11 @@ routes.delete("/api/reminders/:id", (c) => {
 // POST /api/reminders/:id/complete — mark completed
 routes.post("/api/reminders/:id/complete", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 
-	const docId = scheduleDocId(space);
-	const doc = ensureDoc(space);
+	const docId = scheduleDocId(dataSpace);
+	const doc = ensureDoc(dataSpace);
 	if (!doc.reminders[id]) return c.json({ error: "Reminder not found" }, 404);
 
 	_syncServer!.changeDoc<ScheduleDoc>(docId, `complete reminder ${id}`, (d) => {
@@ -1264,11 +1279,12 @@ routes.post("/api/reminders/:id/complete", (c) => {
 // POST /api/reminders/:id/snooze — reschedule to a new date
 routes.post("/api/reminders/:id/snooze", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	const body = await c.req.json();
 
-	const docId = scheduleDocId(space);
-	const doc = ensureDoc(space);
+	const docId = scheduleDocId(dataSpace);
+	const doc = ensureDoc(dataSpace);
 	if (!doc.reminders[id]) return c.json({ error: "Reminder not found" }, 404);
 
 	const newRemindAt = body.remindAt
@@ -1287,7 +1303,7 @@ routes.post("/api/reminders/:id/snooze", async (c) => {
 	const updated = _syncServer!.getDoc<ScheduleDoc>(docId)!;
 	const reminder = updated.reminders[id];
 	if (reminder?.calendarEventId) {
-		const calDocId = calendarDocId(space);
+		const calDocId = calendarDocId(dataSpace);
 		const duration = reminder.allDay ? 86400000 : 3600000;
 		_syncServer!.changeDoc<CalendarDoc>(calDocId, `update reminder event time`, (d) => {
 			const ev = d.events[reminder.calendarEventId!];
diff --git a/modules/rsocials/mod.ts b/modules/rsocials/mod.ts
index a99ef4f..25a30b3 100644
--- a/modules/rsocials/mod.ts
+++ b/modules/rsocials/mod.ts
@@ -179,10 +179,11 @@ routes.get("/api/feed", (c) =>
 
 routes.post("/api/threads/:id/image", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	if (!id || id.includes("..") || id.includes("/")) return c.json({ error: "Invalid ID" }, 400);
 
-	const thread = getThreadFromDoc(space, id);
+	const thread = getThreadFromDoc(dataSpace, id);
 	if (!thread) return c.json({ error: "Thread not found" }, 404);
 
 	if (!process.env.FAL_KEY) return c.json({ error: "FAL_KEY not configured" }, 503);
@@ -210,7 +211,7 @@ routes.post("/api/threads/:id/image", async (c) => {
 	if (!imageUrl) return c.json({ error: "Failed to download image" }, 502);
 
 	// Update Automerge doc with image URL
-	const docId = socialsDocId(space);
+	const docId = socialsDocId(dataSpace);
 	_syncServer!.changeDoc<SocialsDoc>(docId, "set thread image", (d) => {
 		if (d.threads?.[id]) {
 			d.threads[id].imageUrl = imageUrl;
@@ -223,10 +224,11 @@ routes.post("/api/threads/:id/image", async (c) => {
 
 routes.post("/api/threads/:id/upload-image", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	if (!id || id.includes("..") || id.includes("/")) return c.json({ error: "Invalid ID" }, 400);
 
-	const thread = getThreadFromDoc(space, id);
+	const thread = getThreadFromDoc(dataSpace, id);
 	if (!thread) return c.json({ error: "Thread not found" }, 404);
 
 	let formData: FormData;
@@ -246,7 +248,7 @@ routes.post("/api/threads/:id/upload-image", async (c) => {
 	const buffer = Buffer.from(await file.arrayBuffer());
 	const imageUrl = await saveUploadedFile(buffer, filename);
 
-	const docId = socialsDocId(space);
+	const docId = socialsDocId(dataSpace);
 	_syncServer!.changeDoc<SocialsDoc>(docId, "upload thread image", (d) => {
 		if (d.threads?.[id]) {
 			d.threads[id].imageUrl = imageUrl;
@@ -259,12 +261,13 @@ routes.post("/api/threads/:id/upload-image", async (c) => {
 
 routes.post("/api/threads/:id/tweet/:index/upload-image", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	const index = c.req.param("index");
 	if (!id || id.includes("..") || id.includes("/")) return c.json({ error: "Invalid ID" }, 400);
 	if (!/^\d+$/.test(index)) return c.json({ error: "Invalid index" }, 400);
 
-	const thread = getThreadFromDoc(space, id);
+	const thread = getThreadFromDoc(dataSpace, id);
 	if (!thread) return c.json({ error: "Thread not found" }, 404);
 
 	let formData: FormData;
@@ -285,7 +288,7 @@ routes.post("/api/threads/:id/tweet/:index/upload-image", async (c) => {
 	const buffer = Buffer.from(await file.arrayBuffer());
 	const imageUrl = await saveUploadedFile(buffer, filename);
 
-	const docId = socialsDocId(space);
+	const docId = socialsDocId(dataSpace);
 	_syncServer!.changeDoc<SocialsDoc>(docId, "upload tweet image", (d) => {
 		if (d.threads?.[id]) {
 			if (!d.threads[id].tweetImages) d.threads[id].tweetImages = {} as any;
@@ -299,12 +302,13 @@ routes.post("/api/threads/:id/tweet/:index/upload-image", async (c) => {
 
 routes.post("/api/threads/:id/tweet/:index/image", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	const index = c.req.param("index");
 	if (!id || id.includes("..") || id.includes("/")) return c.json({ error: "Invalid ID" }, 400);
 	if (!/^\d+$/.test(index)) return c.json({ error: "Invalid index" }, 400);
 
-	const thread = getThreadFromDoc(space, id);
+	const thread = getThreadFromDoc(dataSpace, id);
 	if (!thread) return c.json({ error: "Thread not found" }, 404);
 
 	const tweetIndex = parseInt(index, 10);
@@ -340,7 +344,7 @@ routes.post("/api/threads/:id/tweet/:index/image", async (c) => {
 	}
 	if (!imageUrl) return c.json({ error: "Failed to download image" }, 502);
 
-	const docId = socialsDocId(space);
+	const docId = socialsDocId(dataSpace);
 	_syncServer!.changeDoc<SocialsDoc>(docId, "generate tweet image", (d) => {
 		if (d.threads?.[id]) {
 			if (!d.threads[id].tweetImages) d.threads[id].tweetImages = {} as any;
@@ -354,19 +358,20 @@ routes.post("/api/threads/:id/tweet/:index/image", async (c) => {
 
 routes.delete("/api/threads/:id/tweet/:index/image", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	const index = c.req.param("index");
 	if (!id || id.includes("..") || id.includes("/")) return c.json({ error: "Invalid ID" }, 400);
 	if (!/^\d+$/.test(index)) return c.json({ error: "Invalid index" }, 400);
 
-	const thread = getThreadFromDoc(space, id);
+	const thread = getThreadFromDoc(dataSpace, id);
 	if (!thread) return c.json({ error: "Thread not found" }, 404);
 
 	if (!thread.tweetImages?.[index]) return c.json({ ok: true });
 
 	await deleteImageFile(thread.tweetImages[index]);
 
-	const docId = socialsDocId(space);
+	const docId = socialsDocId(dataSpace);
 	_syncServer!.changeDoc<SocialsDoc>(docId, "remove tweet image", (d) => {
 		if (d.threads?.[id]?.tweetImages?.[index]) {
 			delete d.threads[id].tweetImages![index];
@@ -382,10 +387,11 @@ routes.delete("/api/threads/:id/tweet/:index/image", async (c) => {
 
 routes.delete("/api/threads/:id/images", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	if (!id || id.includes("..") || id.includes("/")) return c.json({ error: "Invalid ID" }, 400);
 
-	const thread = getThreadFromDoc(space, id);
+	const thread = getThreadFromDoc(dataSpace, id);
 	if (!thread) return c.json({ ok: true }); // Thread already gone
 
 	// Clean up header image
@@ -405,6 +411,7 @@ routes.delete("/api/threads/:id/images", async (c) => {
 
 routes.get("/campaign", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `Campaign — rSocials | rSpace`,
 		moduleId: "rsocials",
@@ -419,10 +426,11 @@ routes.get("/campaign", (c) => {
 
 routes.get("/thread/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	if (!id || id.includes("..") || id.includes("/")) return c.text("Not found", 404);
 
-	const thread = getThreadFromDoc(space, id);
+	const thread = getThreadFromDoc(dataSpace, id);
 	if (!thread) return c.text("Thread not found", 404);
 
 	// OG tags for social crawlers (SSR)
@@ -461,10 +469,11 @@ routes.get("/thread/:id", async (c) => {
 
 routes.get("/thread/:id/edit", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const id = c.req.param("id");
 	if (!id || id.includes("..") || id.includes("/")) return c.text("Not found", 404);
 
-	const thread = getThreadFromDoc(space, id);
+	const thread = getThreadFromDoc(dataSpace, id);
 	if (!thread) return c.text("Thread not found", 404);
 
 	const dataScript = `<script>window.__THREAD_DATA__ = ${JSON.stringify(thread).replace(/</g, "\\u003c")};</script>`;
@@ -483,6 +492,7 @@ routes.get("/thread/:id/edit", async (c) => {
 
 routes.get("/thread", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `Thread Builder — rSocials | rSpace`,
 		moduleId: "rsocials",
@@ -497,6 +507,7 @@ routes.get("/thread", (c) => {
 
 routes.get("/threads", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `Threads — rSocials | rSpace`,
 		moduleId: "rsocials",
@@ -511,6 +522,7 @@ routes.get("/threads", (c) => {
 
 routes.get("/campaigns", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.redirect(`/${space}/rsocials/campaign`);
 });
 
@@ -558,6 +570,7 @@ const POSTIZ_URL = process.env.POSTIZ_URL || "https://demo.rsocials.online";
 
 routes.get("/scheduler", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderExternalAppShell({
 		title: `Post Scheduler — rSocials | rSpace`,
 		moduleId: "rsocials",
@@ -571,6 +584,7 @@ routes.get("/scheduler", (c) => {
 
 routes.get("/feed", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const isDemo = space === "demo";
 	const body = isDemo ? renderDemoFeedHTML() : renderLanding();
 	const styles = isDemo
@@ -589,6 +603,7 @@ routes.get("/feed", (c) => {
 
 routes.get("/landing", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `${space} — rSocials | rSpace`,
 		moduleId: "rsocials",
@@ -604,6 +619,7 @@ routes.get("/landing", (c) => {
 
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `${space} — rSocials | rSpace`,
 		moduleId: "rsocials",
diff --git a/modules/rsplat/mod.ts b/modules/rsplat/mod.ts
index e4284af..305e2ea 100644
--- a/modules/rsplat/mod.ts
+++ b/modules/rsplat/mod.ts
@@ -205,11 +205,12 @@ const routes = new Hono();
 // ── API: List splats ──
 routes.get("/api/splats", async (c) => {
 	const spaceSlug = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	const tag = c.req.query("tag");
 	const limit = Math.min(parseInt(c.req.query("limit") || "50"), 100);
 	const offset = parseInt(c.req.query("offset") || "0");
 
-	const doc = ensureDoc(spaceSlug);
+	const doc = ensureDoc(dataSpace);
 
 	let items = Object.values(doc.items)
 		.filter((item) => item.status === 'published');
@@ -230,9 +231,10 @@ routes.get("/api/splats", async (c) => {
 // ── API: Get splat details ──
 routes.get("/api/splats/:id", async (c) => {
 	const spaceSlug = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	const id = c.req.param("id");
 
-	const doc = ensureDoc(spaceSlug);
+	const doc = ensureDoc(dataSpace);
 	const found = findItem(doc, id);
 
 	if (!found || found[1].status !== 'published') {
@@ -242,7 +244,7 @@ routes.get("/api/splats/:id", async (c) => {
 	const [itemKey, item] = found;
 
 	// Increment view count
-	const docId = splatScenesDocId(spaceSlug);
+	const docId = splatScenesDocId(dataSpace);
 	_syncServer!.changeDoc<SplatScenesDoc>(docId, 'increment view count', (d) => {
 		d.items[itemKey].viewCount += 1;
 	});
@@ -254,9 +256,10 @@ routes.get("/api/splats/:id", async (c) => {
 // Matches both /api/splats/:id/file and /api/splats/:id/:filename (e.g. rainbow-sphere.splat)
 routes.get("/api/splats/:id/:filename", async (c) => {
 	const spaceSlug = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	const id = c.req.param("id");
 
-	const doc = ensureDoc(spaceSlug);
+	const doc = ensureDoc(dataSpace);
 	const found = findItem(doc, id);
 
 	if (!found || found[1].status !== 'published') {
@@ -307,6 +310,7 @@ routes.post("/api/splats", async (c) => {
 	}
 
 	const spaceSlug = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	const formData = await c.req.formData();
 	const file = formData.get("file") as File | null;
 	const title = (formData.get("title") as string || "").trim();
@@ -336,7 +340,7 @@ routes.post("/api/splats", async (c) => {
 	let slug = slugify(title);
 
 	// Check slug collision in Automerge doc
-	const doc = ensureDoc(spaceSlug);
+	const doc = ensureDoc(dataSpace);
 	const slugExists = Object.values(doc.items).some((item) => item.slug === slug);
 	if (slugExists) {
 		slug = `${slug}-${shortId}`;
@@ -354,7 +358,7 @@ routes.post("/api/splats", async (c) => {
 	const now = Date.now();
 	const paymentTx = (c as any).get("x402Payment") || null;
 
-	const docId = splatScenesDocId(spaceSlug);
+	const docId = splatScenesDocId(dataSpace);
 	_syncServer!.changeDoc<SplatScenesDoc>(docId, 'add splat', (d) => {
 		d.items[splatId] = {
 			id: splatId,
@@ -418,6 +422,7 @@ routes.post("/api/splats/from-media", async (c) => {
 	}
 
 	const spaceSlug = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	const formData = await c.req.formData();
 	const title = (formData.get("title") as string || "").trim();
 	const description = (formData.get("description") as string || "").trim() || null;
@@ -463,7 +468,7 @@ routes.post("/api/splats/from-media", async (c) => {
 	let slug = slugify(title);
 
 	// Check slug collision in Automerge doc
-	const doc = ensureDoc(spaceSlug);
+	const doc = ensureDoc(dataSpace);
 	const slugExists = Object.values(doc.items).some((item) => item.slug === slug);
 	if (slugExists) {
 		slug = `${slug}-${shortId}`;
@@ -496,7 +501,7 @@ routes.post("/api/splats/from-media", async (c) => {
 
 	// Insert splat record (pending processing) into Automerge doc
 	const paymentTx = (c as any).get("x402Payment") || null;
-	const docId = splatScenesDocId(spaceSlug);
+	const docId = splatScenesDocId(dataSpace);
 	_syncServer!.changeDoc<SplatScenesDoc>(docId, 'add splat from media', (d) => {
 		d.items[splatId] = {
 			id: splatId,
@@ -549,9 +554,10 @@ routes.delete("/api/splats/:id", async (c) => {
 	}
 
 	const spaceSlug = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	const id = c.req.param("id");
 
-	const doc = ensureDoc(spaceSlug);
+	const doc = ensureDoc(dataSpace);
 	const found = findItem(doc, id);
 
 	if (!found || found[1].status !== 'published') {
@@ -563,7 +569,7 @@ routes.delete("/api/splats/:id", async (c) => {
 		return c.json({ error: "Not authorized" }, 403);
 	}
 
-	const docId = splatScenesDocId(spaceSlug);
+	const docId = splatScenesDocId(dataSpace);
 	_syncServer!.changeDoc<SplatScenesDoc>(docId, 'remove splat', (d) => {
 		d.items[itemKey].status = 'removed';
 	});
@@ -574,8 +580,9 @@ routes.delete("/api/splats/:id", async (c) => {
 // ── Page: Gallery ──
 routes.get("/", async (c) => {
 	const spaceSlug = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 
-	const doc = ensureDoc(spaceSlug);
+	const doc = ensureDoc(dataSpace);
 
 	const items = Object.values(doc.items)
 		.filter((item) => item.status === 'published')
@@ -612,9 +619,10 @@ routes.get("/", async (c) => {
 // ── Page: Viewer ──
 routes.get("/view/:id", async (c) => {
 	const spaceSlug = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	const id = c.req.param("id");
 
-	const doc = ensureDoc(spaceSlug);
+	const doc = ensureDoc(dataSpace);
 	const found = findItem(doc, id);
 
 	if (!found || found[1].status !== 'published') {
@@ -632,7 +640,7 @@ routes.get("/view/:id", async (c) => {
 	const [itemKey, splat] = found;
 
 	// Increment view count
-	const docId = splatScenesDocId(spaceSlug);
+	const docId = splatScenesDocId(dataSpace);
 	_syncServer!.changeDoc<SplatScenesDoc>(docId, 'increment view count', (d) => {
 		d.items[itemKey].viewCount += 1;
 	});
diff --git a/modules/rswag/mod.ts b/modules/rswag/mod.ts
index 1674251..aa9d6d5 100644
--- a/modules/rswag/mod.ts
+++ b/modules/rswag/mod.ts
@@ -230,6 +230,7 @@ routes.get("/api/artifact/:id", async (c) => {
 // ── Page route: swag designer ──
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `Swag Designer | rSpace`,
 		moduleId: "rswag",
diff --git a/modules/rtrips/mod.ts b/modules/rtrips/mod.ts
index 6403757..599cf44 100644
--- a/modules/rtrips/mod.ts
+++ b/modules/rtrips/mod.ts
@@ -68,7 +68,8 @@ const routes = new Hono();
 // GET /api/trips — list trips
 routes.get("/api/trips", async (c) => {
 	const space = c.req.param("space") || "demo";
-	const docIds = listTripDocIds(space);
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
+	const docIds = listTripDocIds(dataSpace);
 
 	const rows = docIds.map((docId) => {
 		const doc = _syncServer!.getDoc<TripDoc>(docId);
@@ -102,11 +103,12 @@ routes.post("/api/trips", async (c) => {
 	if (!title?.trim()) return c.json({ error: "Title required" }, 400);
 
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const tripId = newId();
 	const slug = title.trim().toLowerCase().replace(/[^a-z0-9]+/g, "-").replace(/^-|-$/g, "");
 	const now = Date.now();
 
-	const docId = tripDocId(space, tripId);
+	const docId = tripDocId(dataSpace, tripId);
 	let doc = Automerge.change(Automerge.init<TripDoc>(), 'create trip', (d) => {
 		const init = tripSchema.init();
 		d.meta = init.meta;
@@ -140,8 +142,9 @@ routes.post("/api/trips", async (c) => {
 // GET /api/trips/:id — trip detail with all sub-resources
 routes.get("/api/trips/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const tripId = c.req.param("id");
-	const docId = tripDocId(space, tripId);
+	const docId = tripDocId(dataSpace, tripId);
 	const doc = _syncServer!.getDoc<TripDoc>(docId);
 	if (!doc) return c.json({ error: "Trip not found" }, 404);
 
@@ -163,8 +166,9 @@ routes.get("/api/trips/:id", async (c) => {
 // PUT /api/trips/:id — update trip
 routes.put("/api/trips/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const tripId = c.req.param("id");
-	const docId = tripDocId(space, tripId);
+	const docId = tripDocId(dataSpace, tripId);
 	const doc = _syncServer!.getDoc<TripDoc>(docId);
 	if (!doc) return c.json({ error: "Not found" }, 404);
 
@@ -198,9 +202,10 @@ routes.post("/api/trips/:id/destinations", async (c) => {
 	try { await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
 
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const tripId = c.req.param("id");
-	ensureDoc(space, tripId);
-	const docId = tripDocId(space, tripId);
+	ensureDoc(dataSpace, tripId);
+	const docId = tripDocId(dataSpace, tripId);
 
 	const body = await c.req.json();
 	const destId = newId();
@@ -234,9 +239,10 @@ routes.post("/api/trips/:id/itinerary", async (c) => {
 	try { await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
 
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const tripId = c.req.param("id");
-	ensureDoc(space, tripId);
-	const docId = tripDocId(space, tripId);
+	ensureDoc(dataSpace, tripId);
+	const docId = tripDocId(dataSpace, tripId);
 
 	const body = await c.req.json();
 	const itemId = newId();
@@ -270,9 +276,10 @@ routes.post("/api/trips/:id/bookings", async (c) => {
 	try { await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
 
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const tripId = c.req.param("id");
-	ensureDoc(space, tripId);
-	const docId = tripDocId(space, tripId);
+	ensureDoc(dataSpace, tripId);
+	const docId = tripDocId(dataSpace, tripId);
 
 	const body = await c.req.json();
 	const bookingId = newId();
@@ -307,9 +314,10 @@ routes.post("/api/trips/:id/expenses", async (c) => {
 	try { await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
 
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const tripId = c.req.param("id");
-	ensureDoc(space, tripId);
-	const docId = tripDocId(space, tripId);
+	ensureDoc(dataSpace, tripId);
+	const docId = tripDocId(dataSpace, tripId);
 
 	const body = await c.req.json();
 	const expenseId = newId();
@@ -338,8 +346,9 @@ routes.post("/api/trips/:id/expenses", async (c) => {
 
 routes.get("/api/trips/:id/packing", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const tripId = c.req.param("id");
-	const docId = tripDocId(space, tripId);
+	const docId = tripDocId(dataSpace, tripId);
 	const doc = _syncServer!.getDoc<TripDoc>(docId);
 	if (!doc) return c.json([]);
 
@@ -356,9 +365,10 @@ routes.post("/api/trips/:id/packing", async (c) => {
 	try { await verifyEncryptIDToken(token); } catch { return c.json({ error: "Invalid token" }, 401); }
 
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const tripId = c.req.param("id");
-	ensureDoc(space, tripId);
-	const docId = tripDocId(space, tripId);
+	ensureDoc(dataSpace, tripId);
+	const docId = tripDocId(dataSpace, tripId);
 
 	const body = await c.req.json();
 	const itemId = newId();
@@ -384,10 +394,11 @@ routes.post("/api/trips/:id/packing", async (c) => {
 
 routes.patch("/api/packing/:id", async (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	const packingId = c.req.param("id");
 
 	// Find the trip doc containing this packing item
-	const docIds = listTripDocIds(space);
+	const docIds = listTripDocIds(dataSpace);
 	for (const docId of docIds) {
 		const doc = _syncServer!.getDoc<TripDoc>(docId);
 		if (!doc || !doc.packingItems[packingId]) continue;
@@ -423,6 +434,7 @@ routes.post("/api/route", async (c) => {
 // ── Route planner page ──
 routes.get("/routes", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `${space} — Route Planner | rTrips`,
 		moduleId: "rtrips",
@@ -438,6 +450,7 @@ routes.get("/routes", (c) => {
 // ── Page route ──
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `${space} — Trips | rSpace`,
 		moduleId: "rtrips",
diff --git a/modules/rtube/mod.ts b/modules/rtube/mod.ts
index 7900cfd..c700869 100644
--- a/modules/rtube/mod.ts
+++ b/modules/rtube/mod.ts
@@ -192,6 +192,7 @@ routes.get("/api/health", (c) => c.json({ ok: true }));
 // ── Page route ──
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `${space} — Tube | rSpace`,
 		moduleId: "rtube",
diff --git a/modules/rwallet/mod.ts b/modules/rwallet/mod.ts
index b27bbbd..5a724a5 100644
--- a/modules/rwallet/mod.ts
+++ b/modules/rwallet/mod.ts
@@ -383,6 +383,7 @@ interface BalanceItem {
 // ── Page route ──
 routes.get("/", (c) => {
 	const spaceSlug = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || spaceSlug;
 	return c.html(renderShell({
 		title: `${spaceSlug} — Wallet | rSpace`,
 		moduleId: "rwallet",
diff --git a/modules/rwork/mod.ts b/modules/rwork/mod.ts
index 50b4e02..db8b05e 100644
--- a/modules/rwork/mod.ts
+++ b/modules/rwork/mod.ts
@@ -393,6 +393,7 @@ routes.get("/api/spaces/:slug/activity", async (c) => {
 // ── Page route ──
 routes.get("/", (c) => {
 	const space = c.req.param("space") || "demo";
+	const dataSpace = (c.get("effectiveSpace" as any) as string) || space;
 	return c.html(renderShell({
 		title: `${space} — Work | rSpace`,
 		moduleId: "rwork",
diff --git a/server/index.ts b/server/index.ts
index 66b442e..4c44345 100644
--- a/server/index.ts
+++ b/server/index.ts
@@ -1660,6 +1660,7 @@ app.get("/:space/:moduleId/template", async (c) => {
 // ── Empty-state detection for onboarding ──
 
 import type { RSpaceModule } from "../shared/module";
+import { resolveDataSpace } from "../shared/scope-resolver";
 
 function moduleHasData(space: string, mod: RSpaceModule): boolean {
 	if (space === "demo") return true; // demo always has data
@@ -1681,13 +1682,18 @@ for (const mod of getAllModules()) {
 		if (!space || space === "api" || space.includes(".")) return next();
 
 		// Check enabled modules (skip for core rspace module)
+		const doc = getDocumentData(space);
 		if (mod.id !== "rspace") {
-			const doc = getDocumentData(space);
 			if (doc?.meta?.enabledModules && !doc.meta.enabledModules.includes(mod.id)) {
 				return c.json({ error: "Module not enabled for this space" }, 404);
 			}
 		}
 
+		// Resolve effective data space (global vs space-scoped)
+		const overrides = doc?.meta?.moduleScopeOverrides ?? null;
+		const effectiveSpace = resolveDataSpace(mod.id, space, overrides);
+		c.set("effectiveSpace" as any, effectiveSpace);
+
 		// Resolve caller's role for write-method blocking
 		const method = c.req.method;
 		if (!mod.publicWrite && (method === "POST" || method === "PUT" || method === "PATCH" || method === "DELETE")) {
diff --git a/server/shell.ts b/server/shell.ts
index 73e3a4a..916eb00 100644
--- a/server/shell.ts
+++ b/server/shell.ts
@@ -87,6 +87,10 @@ export function renderShell(opts: ShellOptions): string {
 	const enabledModules = opts.enabledModules ?? spaceMeta?.enabledModules ?? null;
 	const spaceEncrypted = opts.spaceEncrypted ?? spaceMeta?.spaceEncrypted ?? false;
 
+	// Build scope config for client-side runtime
+	const spaceData = getDocumentData(spaceSlug);
+	const scopeOverrides = spaceData?.meta?.moduleScopeOverrides ?? {};
+
 	// Filter modules by enabledModules (null = show all)
 	const visibleModules = enabledModules
 		? modules.filter(m => m.id === "rspace" || enabledModules.includes(m.id))
@@ -119,7 +123,7 @@ export function renderShell(opts: ShellOptions): string {
   <style>${WELCOME_CSS}</style>
   <style>${ACCESS_GATE_CSS}</style>
 </head>
-<body data-space-visibility="${escapeAttr(spaceVisibility)}" data-space-slug="${escapeAttr(spaceSlug)}">
+<body data-space-visibility="${escapeAttr(spaceVisibility)}" data-space-slug="${escapeAttr(spaceSlug)}" data-scope-overrides="${escapeAttr(JSON.stringify(scopeOverrides))}">
   <header class="rstack-header">
     <div class="rstack-header__left">
       <a href="/" style="display:flex;align-items:center;margin-right:4px"><img src="/favicon.png" alt="rSpace" class="rstack-header__logo"></a>
@@ -186,8 +190,9 @@ export function renderShell(opts: ShellOptions): string {
 
     // Restore saved theme preference across header / tab-row
     (function(){try{var t=localStorage.getItem('canvas-theme');if(t)document.querySelectorAll('[data-theme]').forEach(function(el){el.setAttribute('data-theme',t)})}catch(e){}})();
-    // Provide module list to app switcher
-    document.querySelector('rstack-app-switcher')?.setModules(${moduleListJSON});
+    // Provide module list to app switcher and offline runtime
+    window.__rspaceModuleList = ${moduleListJSON};
+    document.querySelector('rstack-app-switcher')?.setModules(window.__rspaceModuleList);
 
     // ── "Try Demo" button visibility ──
     // Hidden when logged in. When logged out, shown everywhere except demo.rspace.online
@@ -391,10 +396,23 @@ export function renderShell(opts: ShellOptions): string {
 
       tabBar.addEventListener('layer-close', (e) => {
         const { layerId } = e.detail;
+        const closedLayer = layers.find(l => l.id === layerId);
         const closedModuleId = layerId.replace('layer-', '');
         tabBar.removeLayer(layerId);
         layers = layers.filter(l => l.id !== layerId);
         saveTabs();
+
+        // If this was a space layer with a persisted SpaceRef, clean it up
+        if (closedLayer?.spaceSlug && closedLayer._spaceRefId) {
+          const token = document.cookie.match(/encryptid_token=([^;]+)/)?.[1];
+          if (token) {
+            fetch('/api/spaces/' + encodeURIComponent(spaceSlug) + '/nest/' + encodeURIComponent(closedLayer._spaceRefId), {
+              method: 'DELETE',
+              headers: { 'Authorization': 'Bearer ' + token },
+            }).catch(() => { /* best-effort cleanup */ });
+          }
+        }
+
         // Remove cached pane from DOM
         if (tabCache) tabCache.removePane(closedModuleId);
         // If we closed the active tab, switch to the first remaining
@@ -415,6 +433,53 @@ export function renderShell(opts: ShellOptions): string {
         document.dispatchEvent(new CustomEvent('layer-view-mode', { detail: { mode } }));
       });
 
+      // ── Space-switch: client-side space navigation ──
+      // When user clicks a space in the space-switcher, handle it client-side
+      // if tabCache is available. Updates URL, tabs, and shell chrome.
+      const spaceSwitcher = document.querySelector('rstack-space-switcher');
+      if (spaceSwitcher) {
+        spaceSwitcher.addEventListener('space-switch', (e) => {
+          const { space: newSpace, moduleId: targetModule, href } = e.detail;
+          if (!tabCache || !newSpace) return;
+
+          e.preventDefault(); // signal to space-switcher that we're handling it
+
+          const targetModuleId = targetModule || currentModuleId;
+
+          tabCache.switchSpace(newSpace, targetModuleId).then(ok => {
+            if (!ok) {
+              // Client-side switch failed — full navigation
+              window.location.href = href || window.__rspaceNavUrl(newSpace, targetModuleId);
+              return;
+            }
+
+            // Update runtime to switch space
+            const runtime = window.__rspaceOfflineRuntime;
+            if (runtime && runtime.switchSpace) runtime.switchSpace(newSpace);
+
+            // Update tab state for the new space
+            const newTabsKey = 'rspace_tabs_' + newSpace;
+            let newLayers;
+            try {
+              const saved = localStorage.getItem(newTabsKey);
+              newLayers = saved ? JSON.parse(saved) : [];
+              if (!Array.isArray(newLayers)) newLayers = [];
+            } catch(e) { newLayers = []; }
+
+            if (!newLayers.find(l => l.moduleId === targetModuleId)) {
+              newLayers.push(makeLayer(targetModuleId, newLayers.length));
+            }
+            localStorage.setItem(newTabsKey, JSON.stringify(newLayers));
+
+            // Update layers reference and tab bar
+            layers = newLayers;
+            tabBar.setLayers(layers);
+            tabBar.setAttribute('active', 'layer-' + targetModuleId);
+            tabBar.setAttribute('space', newSpace);
+          });
+        });
+      }
+
       // ── App-switcher → tab system integration ──
       // When user picks a module from the app-switcher, route through tabs
       // instead of doing a full page navigation.
@@ -445,6 +510,44 @@ export function renderShell(opts: ShellOptions): string {
         });
       }
 
+      // ── Space Layer: cross-space data overlay ──
+      tabBar.addEventListener('space-layer-add', (e) => {
+        const { layer, spaceSlug: layerSpace, role } = e.detail;
+        if (!layers.find(l => l.id === layer.id)) {
+          layers.push(layer);
+        }
+        saveTabs();
+
+        // Persist as a SpaceRef via the nesting API (best-effort)
+        const token = document.cookie.match(/encryptid_token=([^;]+)/)?.[1];
+        if (token) {
+          fetch('/api/spaces/' + encodeURIComponent(spaceSlug) + '/nest', {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json', 'Authorization': 'Bearer ' + token },
+            body: JSON.stringify({
+              sourceSlug: layerSpace,
+              label: layer.label || layerSpace,
+              permissions: { read: true, write: role !== 'viewer' },
+            }),
+          }).then(res => res.json()).then(data => {
+            if (data.ref) layer._spaceRefId = data.ref.id;
+          }).catch(() => { /* best-effort */ });
+        }
+
+        // Connect offline runtime to the source space for cross-space data
+        const runtime = window.__rspaceOfflineRuntime;
+        if (runtime && runtime.connectToSpace) {
+          runtime.connectToSpace(layerSpace).then(() => {
+            // Dispatch event for canvas and modules to pick up the new space layer
+            document.dispatchEvent(new CustomEvent('space-layer-added', {
+              detail: { spaceSlug: layerSpace, role, layerId: layer.id },
+            }));
+          }).catch(() => {
+            console.warn('[shell] Failed to connect to space layer:', layerSpace);
+          });
+        }
+      });
+
       // Expose tabBar for CommunitySync integration
       window.__rspaceTabBar = tabBar;
 
diff --git a/shared/components/rstack-app-switcher.ts b/shared/components/rstack-app-switcher.ts
index 09da706..270b71f 100644
--- a/shared/components/rstack-app-switcher.ts
+++ b/shared/components/rstack-app-switcher.ts
@@ -301,11 +301,16 @@ export class RStackAppSwitcher extends HTMLElement {
 		document.addEventListener("click", this.#outsideClickHandler);
 
 		// Intercept same-origin module links → dispatch event for tab system
+		// Only intercept when the shell tab system is active (window.__rspaceTabBar).
+		// On landing pages (rspace.online/, rspace.online/{moduleId}), let links
+		// navigate normally since there's no module-select listener.
 		this.#shadow.querySelectorAll("a.item").forEach((el) => {
 			el.addEventListener("click", (e) => {
 				const moduleId = (el as HTMLElement).dataset.id;
 				if (!moduleId) return;
-				// Only intercept same-origin links (skip bare-domain landing pages)
+				// Skip interception if tab system isn't active (landing pages)
+				if (!(window as any).__rspaceTabBar) return;
+				// Only intercept same-origin links
 				const href = (el as HTMLAnchorElement).href;
 				try {
 					const url = new URL(href, window.location.href);
diff --git a/shared/components/rstack-space-switcher.ts b/shared/components/rstack-space-switcher.ts
index 9b89c08..dc4657d 100644
--- a/shared/components/rstack-space-switcher.ts
+++ b/shared/components/rstack-space-switcher.ts
@@ -250,6 +250,51 @@ export class RStackSpaceSwitcher extends HTMLElement {
 			});
 		});
 
+		// Intercept space link clicks — dispatch space-switch event for client-side switching
+		menu.querySelectorAll("a.item[href]").forEach((link) => {
+			link.addEventListener("click", (e) => {
+				const href = link.getAttribute("href") || "";
+				// Extract space slug from the link
+				const linkEl = link as HTMLElement;
+				const row = linkEl.closest(".item-row");
+				// Find the space slug from the href pattern
+				const match = href.match(/^(?:https?:\/\/([^.]+)\.rspace\.online)?\/([^/?]+)/);
+				let spaceSlug = "";
+				let moduleTarget = moduleId;
+				if (match) {
+					if (match[1]) {
+						spaceSlug = match[1]; // subdomain pattern
+					} else {
+						// path pattern: /{space}/{moduleId} or /{moduleId}
+						spaceSlug = match[2];
+					}
+				}
+				// Also try data attribute on parent
+				if (!spaceSlug) return; // let default navigation handle it
+
+				// If same space, ignore
+				if (spaceSlug === current) {
+					menu.classList.remove("open");
+					return;
+				}
+
+				// Dispatch space-switch event for client-side handling
+				const event = new CustomEvent("space-switch", {
+					bubbles: true,
+					composed: true,
+					detail: { space: spaceSlug, moduleId: moduleTarget, href },
+				});
+				const handled = this.dispatchEvent(event);
+
+				// If a listener called preventDefault(), we handled it client-side
+				if (event.defaultPrevented) {
+					e.preventDefault();
+					menu.classList.remove("open");
+				}
+				// Otherwise, let the default navigation happen
+			});
+		});
+
 		// Attach Edit Space gear button listeners
 		menu.querySelectorAll(".item-gear").forEach((btn) => {
 			btn.addEventListener("click", (e) => {
diff --git a/shared/components/rstack-tab-bar.ts b/shared/components/rstack-tab-bar.ts
index 43b7ff8..9ba1259 100644
--- a/shared/components/rstack-tab-bar.ts
+++ b/shared/components/rstack-tab-bar.ts
@@ -234,6 +234,114 @@ export class RStackTabBar extends HTMLElement {
 		}
 	}
 
+	// ── Space Layer Picker ──
+
+	/** Show a popup to pick a space to add as a composable layer. */
+	async #showSpaceLayerPicker() {
+		// Remove any existing picker
+		this.#shadow.querySelector(".space-layer-picker")?.remove();
+
+		// Fetch spaces from the API
+		let spaces: Array<{ slug: string; name: string; icon?: string; role?: string }> = [];
+		try {
+			const token = localStorage.getItem("encryptid_session");
+			const headers: Record<string, string> = {};
+			if (token) {
+				try {
+					const session = JSON.parse(token);
+					if (session?.accessToken) headers["Authorization"] = `Bearer ${session.accessToken}`;
+				} catch { /* ignore */ }
+			}
+			const res = await fetch("/api/spaces", { headers });
+			if (res.ok) {
+				const data = await res.json();
+				spaces = (data.spaces || []).filter(
+					(s: any) => s.slug !== this.space && s.role // only spaces user has access to
+				);
+			}
+		} catch { /* offline */ }
+
+		// Filter out spaces already added as layers
+		const existingSpaceSlugs = new Set(
+			this.#layers.filter(l => l.spaceSlug).map(l => l.spaceSlug)
+		);
+		spaces = spaces.filter(s => !existingSpaceSlugs.has(s.slug));
+
+		// Build picker HTML
+		let pickerHtml = `<div class="space-layer-picker">
+			<div class="space-layer-picker__header">
+				<span>Add Space Layer</span>
+				<button class="space-layer-picker__close" id="slp-close">&times;</button>
+			</div>`;
+
+		if (spaces.length === 0) {
+			pickerHtml += `<div class="space-layer-picker__empty">No other spaces available</div>`;
+		} else {
+			for (const s of spaces) {
+				const roleLabel = s.role === "viewer" ? "view only" : s.role || "";
+				pickerHtml += `
+					<button class="space-layer-picker__item" data-slug="${s.slug}" data-name="${(s.name || s.slug).replace(/"/g, '&quot;')}" data-role="${s.role || 'viewer'}">
+						<span class="space-layer-picker__icon">${s.icon || "🌐"}</span>
+						<span class="space-layer-picker__name">${s.name || s.slug}</span>
+						<span class="space-layer-picker__role">${roleLabel}</span>
+					</button>`;
+			}
+		}
+
+		pickerHtml += `</div>`;
+
+		// Inject into shadow DOM
+		const container = document.createElement("div");
+		container.innerHTML = pickerHtml;
+		const picker = container.firstElementChild!;
+		this.#shadow.appendChild(picker);
+
+		// Close button
+		this.#shadow.getElementById("slp-close")?.addEventListener("click", () => {
+			picker.remove();
+		});
+
+		// Space item clicks
+		picker.querySelectorAll<HTMLElement>(".space-layer-picker__item").forEach(item => {
+			item.addEventListener("click", () => {
+				const slug = item.dataset.slug!;
+				const name = item.dataset.name || slug;
+				const role = (item.dataset.role || "viewer") as Layer["spaceRole"];
+
+				const layer: Layer = {
+					id: `layer-space-${slug}`,
+					moduleId: "rspace",
+					label: `${name}`,
+					order: this.#layers.length,
+					color: "",
+					visible: true,
+					createdAt: Date.now(),
+					spaceSlug: slug,
+					spaceRole: role,
+				};
+
+				this.addLayer(layer);
+				this.dispatchEvent(new CustomEvent("space-layer-add", {
+					detail: { layer, spaceSlug: slug, role },
+					bubbles: true,
+				}));
+
+				picker.remove();
+			});
+		});
+
+		// Close on outside click
+		setTimeout(() => {
+			const handler = (e: Event) => {
+				if (!picker.contains(e.target as Node)) {
+					picker.remove();
+					document.removeEventListener("click", handler);
+				}
+			};
+			document.addEventListener("click", handler);
+		}, 0);
+	}
+
 	// ── Feed compatibility helpers ──
 
 	/** Get the set of FlowKinds a module can output (from its feeds) */
@@ -318,14 +426,25 @@ export class RStackTabBar extends HTMLElement {
 		const isActive = layer.id === activeId;
 		const badgeColor = layer.color || badge?.color || "#94a3b8";
 
+		const isSpaceLayer = !!layer.spaceSlug;
+		const spaceLayerClass = isSpaceLayer ? " tab--space-layer" : "";
+		const spaceTag = isSpaceLayer
+			? `<span class="tab-space-tag" title="From ${layer.spaceSlug}">${layer.spaceSlug}</span>`
+			: "";
+		const readOnlyTag = isSpaceLayer && layer.spaceRole === "viewer"
+			? `<span class="tab-readonly-tag" title="View only">👁</span>`
+			: "";
+
 		return `
-			<div class="tab ${isActive ? "active" : ""}"
+			<div class="tab ${isActive ? "active" : ""}${spaceLayerClass}"
 			     data-layer-id="${layer.id}"
 			     data-module-id="${layer.moduleId}"
+			     ${isSpaceLayer ? `data-space-slug="${layer.spaceSlug}"` : ""}
 			     draggable="true">
 				<span class="tab-indicator" style="background:${badgeColor}"></span>
 				<span class="tab-badge" style="background:${badgeColor}">${badge?.badge || layer.moduleId.slice(0, 2)}</span>
 				<span class="tab-label">${layer.label}</span>
+				${spaceTag}${readOnlyTag}
 				${this.#layers.length > 1 ? `<button class="tab-close" data-close="${layer.id}">&times;</button>` : ""}
 			</div>
 		`;
@@ -385,6 +504,16 @@ export class RStackTabBar extends HTMLElement {
 			html += uncategorized.map(m => this.#renderAddMenuItem(m, existingModuleIds.has(m.id))).join("");
 		}
 
+		// ── Add Space Layer section ──
+		html += `<div class="add-menu-divider"></div>`;
+		html += `<button class="add-menu-item add-menu-item--space-layer" id="add-space-layer-btn">
+			<span class="add-menu-icon">🌐</span>
+			<div class="add-menu-text">
+				<span class="add-menu-name">Add Space Layer</span>
+				<span class="add-menu-desc">Overlay data from another space</span>
+			</div>
+		</button>`;
+
 		return `<div class="add-menu" id="add-menu">${html}</div>`;
 	}
 
@@ -898,6 +1027,16 @@ export class RStackTabBar extends HTMLElement {
 			item.addEventListener("touchend", handleSelect);
 		});
 
+		// Add Space Layer button handler
+		const spaceLayerBtn = this.#shadow.getElementById("add-space-layer-btn");
+		if (spaceLayerBtn) {
+			spaceLayerBtn.addEventListener("click", (e) => {
+				e.stopPropagation();
+				this.#addMenuOpen = false;
+				this.#showSpaceLayerPicker();
+			});
+		}
+
 		// Close add menu on outside click/touch
 		if (this.#addMenuOpen) {
 			const handler = () => {
@@ -1310,6 +1449,33 @@ const STYLES = `
 .tab:hover .tab-close { opacity: 0.6; }
 .tab-close:hover { opacity: 1 !important; background: rgba(239,68,68,0.2); color: #ef4444; }
 
+/* Space layer tab styling */
+.tab--space-layer {
+  border: 1px dashed rgba(99,102,241,0.4);
+  background: rgba(99,102,241,0.05);
+}
+.tab--space-layer.active {
+  border-color: rgba(99,102,241,0.6);
+  background: rgba(99,102,241,0.1);
+}
+.tab-space-tag {
+  font-size: 0.6rem;
+  padding: 1px 4px;
+  border-radius: 3px;
+  background: rgba(99,102,241,0.15);
+  color: #a5b4fc;
+  max-width: 50px;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  flex-shrink: 0;
+}
+.tab-readonly-tag {
+  font-size: 0.65rem;
+  flex-shrink: 0;
+  opacity: 0.7;
+}
+
 /* ── Drag states ── */
 
 .tab.dragging { opacity: 0.4; }
@@ -1469,6 +1635,98 @@ const STYLES = `
   opacity: 0.5;
 }
 
+.add-menu-divider {
+  height: 1px;
+  margin: 4px 8px;
+  background: var(--rs-border-subtle);
+}
+
+.add-menu-item--space-layer {
+  border-top: none;
+}
+.add-menu-item--space-layer .add-menu-icon {
+  font-size: 1rem;
+}
+
+/* ── Space Layer Picker ── */
+
+.space-layer-picker {
+  position: absolute;
+  top: 100%;
+  right: 0;
+  min-width: 240px;
+  max-height: 320px;
+  overflow-y: auto;
+  background: var(--rs-bg-surface);
+  border: 1px solid var(--rs-border);
+  border-radius: 12px;
+  box-shadow: var(--rs-shadow-lg);
+  z-index: 10002;
+  margin-top: 4px;
+}
+.space-layer-picker__header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 10px 14px 6px;
+  font-size: 0.75rem;
+  font-weight: 700;
+  text-transform: uppercase;
+  letter-spacing: 0.05em;
+  color: var(--rs-text-secondary);
+}
+.space-layer-picker__close {
+  background: none;
+  border: none;
+  color: var(--rs-text-muted);
+  font-size: 1.1rem;
+  cursor: pointer;
+  padding: 2px 6px;
+  border-radius: 4px;
+  line-height: 1;
+}
+.space-layer-picker__close:hover {
+  color: var(--rs-text-primary);
+  background: var(--rs-bg-hover);
+}
+.space-layer-picker__item {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  width: 100%;
+  padding: 8px 14px;
+  border: none;
+  background: none;
+  cursor: pointer;
+  transition: background 0.12s;
+  text-align: left;
+  font-family: inherit;
+  color: var(--rs-text-primary);
+}
+.space-layer-picker__item:hover {
+  background: var(--rs-bg-hover);
+}
+.space-layer-picker__icon {
+  font-size: 1.1rem;
+  flex-shrink: 0;
+}
+.space-layer-picker__name {
+  font-size: 0.85rem;
+  font-weight: 500;
+  flex: 1;
+}
+.space-layer-picker__role {
+  font-size: 0.7rem;
+  color: var(--rs-text-muted);
+  flex-shrink: 0;
+}
+.space-layer-picker__empty {
+  padding: 16px;
+  text-align: center;
+  font-size: 0.8rem;
+  color: var(--rs-text-muted);
+}
+
 /* ── View toggle ── */
 
 .view-toggle {
diff --git a/shared/local-first/runtime.ts b/shared/local-first/runtime.ts
index 67da95b..fdf34e0 100644
--- a/shared/local-first/runtime.ts
+++ b/shared/local-first/runtime.ts
@@ -46,13 +46,17 @@ export class RSpaceOfflineRuntime {
 	#store: EncryptedDocStore;
 	#sync: DocSyncManager;
 	#crypto: DocCrypto;
-	#space: string;
+	#activeSpace: string;
 	#status: RuntimeStatus = 'idle';
 	#statusListeners = new Set<StatusCallback>();
 	#initialized = false;
+	/** Module scope config: moduleId → 'global' | 'space'. Set from page's module list. */
+	#moduleScopes = new Map<string, 'global' | 'space'>();
+	/** Lazy WebSocket connections per space slug (for cross-space subscriptions). */
+	#spaceConnections = new Map<string, DocSyncManager>();
 
 	constructor(space: string) {
-		this.#space = space;
+		this.#activeSpace = space;
 		this.#crypto = new DocCrypto();
 		this.#documents = new DocumentManager();
 		this.#store = new EncryptedDocStore(space);
@@ -64,7 +68,7 @@ export class RSpaceOfflineRuntime {
 
 	// ── Getters ──
 
-	get space(): string { return this.#space; }
+	get space(): string { return this.#activeSpace; }
 	get isInitialized(): boolean { return this.#initialized; }
 	get isOnline(): boolean { return this.#sync.isConnected; }
 	get status(): RuntimeStatus { return this.#status; }
@@ -85,13 +89,13 @@ export class RSpaceOfflineRuntime {
 
 			// 2. Connect WebSocket (non-blocking — works offline)
 			const proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
-			const wsUrl = `${proto}//${location.host}/ws/${this.#space}`;
+			const wsUrl = `${proto}//${location.host}/ws/${this.#activeSpace}`;
 
 			this.#sync.onConnect(() => this.#setStatus('online'));
 			this.#sync.onDisconnect(() => this.#setStatus('offline'));
 
 			try {
-				await this.#sync.connect(wsUrl, this.#space);
+				await this.#sync.connect(wsUrl, this.#activeSpace);
 				this.#setStatus('online');
 			} catch {
 				// WebSocket failed — still usable offline
@@ -175,10 +179,32 @@ export class RSpaceOfflineRuntime {
 	}
 
 	/**
-	 * Build a DocumentId for a module using the current space.
+	 * Configure module scope information from the page's module list.
+	 * Call once after init with the modules config for this space.
+	 */
+	setModuleScopes(scopes: Array<{ id: string; scope: 'global' | 'space' }>): void {
+		this.#moduleScopes.clear();
+		for (const { id, scope } of scopes) {
+			this.#moduleScopes.set(id, scope);
+		}
+	}
+
+	/**
+	 * Resolve the data-space prefix for a module.
+	 * Returns 'global' for global-scoped modules, the current space otherwise.
+	 */
+	resolveDocSpace(moduleId: string): string {
+		const scope = this.#moduleScopes.get(moduleId);
+		return scope === 'global' ? 'global' : this.#activeSpace;
+	}
+
+	/**
+	 * Build a DocumentId for a module, respecting scope resolution.
+	 * Global-scoped modules get `global:module:collection` prefix.
 	 */
 	makeDocId(module: string, collection: string, itemId?: string): DocumentId {
-		return makeDocumentId(this.#space, module, collection, itemId);
+		const dataSpace = this.resolveDocSpace(module);
+		return makeDocumentId(dataSpace, module, collection, itemId);
 	}
 
 	/**
@@ -200,7 +226,8 @@ export class RSpaceOfflineRuntime {
 	): Promise<Map<DocumentId, Automerge.Doc<T>>> {
 		this.#documents.registerSchema(schema);
 
-		const prefix = `${this.#space}:${module}:${collection}`;
+		const dataSpace = this.resolveDocSpace(module);
+		const prefix = `${dataSpace}:${module}:${collection}`;
 		const docIds = await this.#sync.requestDocList(prefix);
 
 		const results = new Map<DocumentId, Automerge.Doc<T>>();
@@ -231,10 +258,133 @@ export class RSpaceOfflineRuntime {
 	}
 
 	/**
-	 * Tear down: flush, disconnect, clear listeners.
+	 * Switch the active space context without destroying existing connections.
+	 * Previous space's WebSocket stays alive for cross-space subscriptions.
+	 */
+	switchSpace(newSpace: string): void {
+		if (newSpace === this.#activeSpace) return;
+
+		// Store the current connection for cross-space access
+		if (!this.#spaceConnections.has(this.#activeSpace)) {
+			this.#spaceConnections.set(this.#activeSpace, this.#sync);
+		}
+
+		this.#activeSpace = newSpace;
+
+		// Re-use existing connection if we've visited this space before
+		const existing = this.#spaceConnections.get(newSpace);
+		if (existing) {
+			this.#sync = existing;
+			return;
+		}
+
+		// Create a new sync manager for the new space
+		const newSync = new DocSyncManager({
+			documents: this.#documents,
+			store: this.#store,
+		});
+		this.#sync = newSync;
+		this.#spaceConnections.set(newSpace, newSync);
+
+		// Connect lazily — will connect when first doc is subscribed
+		const proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
+		const wsUrl = `${proto}//${location.host}/ws/${newSpace}`;
+		newSync.onConnect(() => this.#setStatus('online'));
+		newSync.onDisconnect(() => this.#setStatus('offline'));
+		newSync.connect(wsUrl, newSpace).catch(() => {
+			this.#setStatus('offline');
+		});
+	}
+
+	/**
+	 * Get all spaces that have active connections (current + cross-space layers).
+	 * Modules use this to aggregate data from all active space layers.
+	 * Returns array of { space, sync } pairs for iteration.
+	 */
+	getAllActiveSpaces(): Array<{ space: string; sync: DocSyncManager }> {
+		const result: Array<{ space: string; sync: DocSyncManager }> = [
+			{ space: this.#activeSpace, sync: this.#sync },
+		];
+		for (const [space, sync] of this.#spaceConnections) {
+			if (space !== this.#activeSpace) {
+				result.push({ space, sync });
+			}
+		}
+		return result;
+	}
+
+	/**
+	 * Subscribe to a module's docs across all active spaces.
+	 * Returns merged results from the current space + all space layers.
+	 */
+	async subscribeModuleAcrossSpaces<T extends Record<string, any>>(
+		module: string,
+		collection: string,
+		schema: DocSchema<T>,
+	): Promise<Map<DocumentId, { doc: Automerge.Doc<T>; space: string }>> {
+		this.#documents.registerSchema(schema);
+		const results = new Map<DocumentId, { doc: Automerge.Doc<T>; space: string }>();
+
+		for (const { space, sync } of this.getAllActiveSpaces()) {
+			const dataSpace = this.#moduleScopes.get(module) === 'global' ? 'global' : space;
+			const prefix = `${dataSpace}:${module}:${collection}`;
+			try {
+				const docIds = await sync.requestDocList(prefix);
+				for (const id of docIds) {
+					const docId = id as DocumentId;
+					if (results.has(docId)) continue; // global docs already seen
+					const doc = await this.subscribe<T>(docId, schema);
+					results.set(docId, { doc, space });
+				}
+			} catch {
+				// Cross-space fetch failed — skip silently
+			}
+		}
+		return results;
+	}
+
+	/**
+	 * Get a sync manager for a specific space (lazy connect).
+	 * Used for cross-space subscriptions (space layers).
+	 */
+	async connectToSpace(spaceSlug: string): Promise<DocSyncManager> {
+		// Already connected?
+		const existing = this.#spaceConnections.get(spaceSlug);
+		if (existing) return existing;
+
+		// Current space
+		if (spaceSlug === this.#activeSpace) return this.#sync;
+
+		// Create new connection
+		const sync = new DocSyncManager({
+			documents: this.#documents,
+			store: this.#store,
+		});
+		this.#spaceConnections.set(spaceSlug, sync);
+
+		const proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
+		const wsUrl = `${proto}//${location.host}/ws/${spaceSlug}`;
+		sync.onConnect(() => { /* cross-space connected */ });
+		sync.onDisconnect(() => { /* cross-space disconnected */ });
+
+		try {
+			await sync.connect(wsUrl, spaceSlug);
+		} catch {
+			// Cross-space connection failed — operate offline for this space
+		}
+
+		return sync;
+	}
+
+	/**
+	 * Tear down: flush, disconnect all connections, clear listeners.
 	 */
 	destroy(): void {
 		this.#sync.disconnect();
+		for (const [, sync] of this.#spaceConnections) {
+			sync.disconnect();
+		}
+		this.#spaceConnections.clear();
 		this.#statusListeners.clear();
 		this.#initialized = false;
 		this.#setStatus('idle');
diff --git a/shared/scope-resolver.ts b/shared/scope-resolver.ts
new file mode 100644
index 0000000..baa6ea7
--- /dev/null
+++ b/shared/scope-resolver.ts
@@ -0,0 +1,28 @@
+/**
+ * Scope resolver — determines whether a module's data lives per-space or globally.
+ *
+ * When a module declares `defaultScope: 'global'`, its Automerge documents
+ * use the `global:` prefix instead of `{space}:`, so data is shared across
+ * all spaces. Space owners can override this per-module via `moduleScopeOverrides`.
+ */
+
+import { getModule } from './module';
+import type { ModuleScope } from './module';
+
+/**
+ * Resolve the effective data-space prefix for a module.
+ *
+ * Returns 'global' if the module should use global-scoped data,
+ * otherwise returns the current space slug for space-scoped data.
+ */
+export function resolveDataSpace(
+	moduleId: string,
+	spaceSlug: string,
+	scopeOverrides?: Record<string, ModuleScope> | null,
+): string {
+	const mod = getModule(moduleId);
+	if (!mod) return spaceSlug;
+
+	const effectiveScope = scopeOverrides?.[moduleId] ?? mod.scoping.defaultScope;
+	return effectiveScope === 'global' ? 'global' : spaceSlug;
+}
diff --git a/shared/tab-cache.ts b/shared/tab-cache.ts
index 06d34cb..4a856dc 100644
--- a/shared/tab-cache.ts
+++ b/shared/tab-cache.ts
@@ -1,10 +1,14 @@
 /**
- * Client-side tab cache for instant tab switching.
+ * Client-side tab cache for instant tab and space switching.
  *
  * Instead of full page navigations, previously loaded tabs are kept in the DOM
  * and shown/hidden via CSS. New tabs are fetched via fetch() + DOMParser on
  * first visit, then stay in the DOM forever.
  *
+ * Pane keys are `${spaceSlug}:${moduleId}` so panes from different spaces
+ * coexist in the DOM. On space switch, current space's panes are hidden and
+ * the target space's panes are shown (or fetched on first visit).
+ *
  * Hiding preserves ALL component state: Shadow DOM, event listeners,
  * WebSocket connections, timers.
  */
@@ -19,22 +23,40 @@ export class TabCache {
 		this.currentModuleId = moduleId;
 	}
 
+	/** Current space slug */
+	get currentSpace(): string {
+		return this.spaceSlug;
+	}
+
+	/** Current module ID */
+	get currentModule(): string {
+		return this.currentModuleId;
+	}
+
+	/** Build the composite pane key */
+	private paneKey(space: string, moduleId: string): string {
+		return `${space}:${moduleId}`;
+	}
+
 	/** Wrap the initial #app content in a pane div and set up popstate */
 	init(): boolean {
 		const app = document.getElementById("app");
 		if (!app) return false;
 
+		const key = this.paneKey(this.spaceSlug, this.currentModuleId);
+
 		// Wrap existing content in a pane
 		const pane = document.createElement("div");
 		pane.className = "rspace-tab-pane rspace-tab-pane--active";
 		pane.dataset.moduleId = this.currentModuleId;
+		pane.dataset.spaceSlug = this.spaceSlug;
 		pane.dataset.pageTitle = document.title;
 
 		while (app.firstChild) {
 			pane.appendChild(app.firstChild);
 		}
 		app.appendChild(pane);
-		this.panes.set(this.currentModuleId, pane);
+		this.panes.set(key, pane);
 
 		// Push initial state into history
 		history.replaceState(
@@ -46,8 +68,18 @@ export class TabCache {
 		// Handle browser back/forward
 		window.addEventListener("popstate", (e) => {
 			const state = e.state;
-			if (state?.moduleId && this.panes.has(state.moduleId)) {
-				this.showPane(state.moduleId);
+			if (!state?.moduleId) {
+				window.location.reload();
+				return;
+			}
+			const stateSpace = state.spaceSlug || this.spaceSlug;
+			const key = this.paneKey(stateSpace, state.moduleId);
+			if (this.panes.has(key)) {
+				if (stateSpace !== this.spaceSlug) {
+					this.hideAllPanes();
+					this.spaceSlug = stateSpace;
+				}
+				this.showPane(stateSpace, state.moduleId);
 			} else {
 				window.location.reload();
 			}
@@ -56,43 +88,84 @@ export class TabCache {
 		return true;
 	}
 
-	/** Switch to a module tab. Returns true if handled client-side. */
+	/** Switch to a module tab within the current space. Returns true if handled client-side. */
 	async switchTo(moduleId: string): Promise<boolean> {
-		if (moduleId === this.currentModuleId) return true;
+		const key = this.paneKey(this.spaceSlug, moduleId);
+		if (moduleId === this.currentModuleId && this.panes.has(key)) return true;
 
-		if (this.panes.has(moduleId)) {
-			this.showPane(moduleId);
-			this.updateUrl(moduleId);
+		if (this.panes.has(key)) {
+			this.showPane(this.spaceSlug, moduleId);
+			this.updateUrl(this.spaceSlug, moduleId);
 			return true;
 		}
 
-		return this.fetchAndInject(moduleId);
+		return this.fetchAndInject(this.spaceSlug, moduleId);
+	}
+
+	/**
+	 * Switch to a different space, loading a module within it.
+	 * Hides all panes from the current space, shows/fetches the target space's pane.
+	 * Returns true if handled client-side.
+	 */
+	async switchSpace(newSpace: string, moduleId: string): Promise<boolean> {
+		if (newSpace === this.spaceSlug && moduleId === this.currentModuleId) return true;
+
+		const key = this.paneKey(newSpace, moduleId);
+
+		// Hide all current panes
+		this.hideAllPanes();
+
+		// Update active space
+		const oldSpace = this.spaceSlug;
+		this.spaceSlug = newSpace;
+
+		if (this.panes.has(key)) {
+			this.showPane(newSpace, moduleId);
+			this.updateUrl(newSpace, moduleId);
+			this.updateSpaceChrome(newSpace);
+			return true;
+		}
+
+		const ok = await this.fetchAndInject(newSpace, moduleId);
+		if (ok) {
+			this.updateSpaceChrome(newSpace);
+			return true;
+		}
+
+		// Rollback on failure
+		this.spaceSlug = oldSpace;
+		return false;
 	}
 
 	/** Check if a pane exists in the DOM cache */
 	has(moduleId: string): boolean {
-		return this.panes.has(moduleId);
+		return this.panes.has(this.paneKey(this.spaceSlug, moduleId));
 	}
 
 	/** Remove a cached pane from the DOM */
 	removePane(moduleId: string): void {
-		const pane = this.panes.get(moduleId);
+		const key = this.paneKey(this.spaceSlug, moduleId);
+		const pane = this.panes.get(key);
 		if (pane) {
 			pane.remove();
-			this.panes.delete(moduleId);
+			this.panes.delete(key);
 		}
 	}
 
 	/** Fetch a module page, extract content, and inject into a new pane */
-	private async fetchAndInject(moduleId: string): Promise<boolean> {
+	private async fetchAndInject(space: string, moduleId: string): Promise<boolean> {
 		const navUrl = (window as any).__rspaceNavUrl;
 		if (!navUrl) return false;
-		const url: string = navUrl(this.spaceSlug, moduleId);
+		const url: string = navUrl(space, moduleId);
 
-		// Cross-origin URLs → fall back to full navigation
+		// For cross-space fetches, use the path-based API to stay same-origin
+		let fetchUrl = url;
 		try {
 			const resolved = new URL(url, window.location.href);
-			if (resolved.origin !== window.location.origin) return false;
+			if (resolved.origin !== window.location.origin) {
+				// Rewrite subdomain URL to path format: /{space}/{moduleId}
+				fetchUrl = `/${space}/${moduleId}`;
+			}
 		} catch {
 			return false;
 		}
@@ -109,7 +182,7 @@ export class TabCache {
 		app.appendChild(loadingPane);
 
 		try {
-			const resp = await fetch(url);
+			const resp = await fetch(fetchUrl);
 			if (!resp.ok) {
 				loadingPane.remove();
 				return false;
@@ -125,23 +198,26 @@ export class TabCache {
 			// Remove loading spinner
 			loadingPane.remove();
 
+			const key = this.paneKey(space, moduleId);
+
 			// Create the real pane
 			const pane = document.createElement("div");
 			pane.className = "rspace-tab-pane rspace-tab-pane--active";
 			pane.dataset.moduleId = moduleId;
+			pane.dataset.spaceSlug = space;
 			pane.dataset.pageTitle = content.title;
 			pane.innerHTML = content.body;
 			app.appendChild(pane);
-			this.panes.set(moduleId, pane);
+			this.panes.set(key, pane);
 
 			// Load module-specific assets
-			this.loadAssets(content.scripts, content.styles, content.inlineStyles, moduleId);
+			this.loadAssets(content.scripts, content.styles, content.inlineStyles, `${space}-${moduleId}`);
 
 			// Update shell state
 			this.currentModuleId = moduleId;
 			document.title = content.title;
 			this.updateShellState(moduleId);
-			this.updateUrl(moduleId);
+			this.updateUrl(space, moduleId);
 			this.updateCanvasLayout(moduleId);
 
 			return true;
@@ -240,9 +316,10 @@ export class TabCache {
 	}
 
 	/** Show a specific pane and update shell state */
-	private showPane(moduleId: string): void {
+	private showPane(space: string, moduleId: string): void {
 		this.hideAllPanes();
-		const pane = this.panes.get(moduleId);
+		const key = this.paneKey(space, moduleId);
+		const pane = this.panes.get(key);
 		if (pane) {
 			pane.classList.add("rspace-tab-pane--active");
 			const storedTitle = pane.dataset.pageTitle;
@@ -282,13 +359,26 @@ export class TabCache {
 		}
 	}
 
+	/** Update space-specific shell chrome (space switcher, body attrs) */
+	private updateSpaceChrome(newSpace: string): void {
+		// Update space-switcher attribute
+		const spaceSwitcher = document.querySelector("rstack-space-switcher");
+		if (spaceSwitcher) {
+			spaceSwitcher.setAttribute("current", newSpace);
+			spaceSwitcher.setAttribute("name", newSpace);
+		}
+
+		// Update body data attribute
+		document.body?.setAttribute("data-space-slug", newSpace);
+	}
+
 	/** Push new URL to browser history */
-	private updateUrl(moduleId: string): void {
+	private updateUrl(space: string, moduleId: string): void {
 		const navUrl = (window as any).__rspaceNavUrl;
 		if (!navUrl) return;
-		const url: string = navUrl(this.spaceSlug, moduleId);
+		const url: string = navUrl(space, moduleId);
 		history.pushState(
-			{ moduleId, spaceSlug: this.spaceSlug },
+			{ moduleId, spaceSlug: space },
 			"",
 			url,
 		);
diff --git a/website/canvas.html b/website/canvas.html
index a8a6cf9..0e9090d 100644
--- a/website/canvas.html
+++ b/website/canvas.html
@@ -1339,6 +1339,25 @@
 				display: none !important;
 			}
 
+			/* Cross-space shape styling — colored border + source badge */
+			.rspace-cross-space-shape {
+				outline: 2px dashed rgba(99, 102, 241, 0.5) !important;
+				outline-offset: 2px;
+			}
+			.rspace-cross-space-shape::after {
+				content: attr(data-source-space);
+				position: absolute;
+				top: -18px;
+				right: 0;
+				font-size: 0.55rem;
+				padding: 1px 5px;
+				border-radius: 3px;
+				background: rgba(99, 102, 241, 0.8);
+				color: white;
+				pointer-events: none;
+				white-space: nowrap;
+			}
+
 			#select-rect {
 				position: fixed;
 				border: 1.5px solid #3b82f6;
@@ -2438,6 +2457,49 @@
 				});
 			}
 
+			// ── Space Layer: overlay shapes from other spaces ──
+			document.addEventListener('space-layer-added', (e) => {
+				const { spaceSlug: layerSpace, role, layerId } = e.detail;
+				if (!sync || !layerSpace) return;
+
+				// Fetch shapes from the other space's canvas
+				fetch(`/${layerSpace}/rspace/api/shapes`)
+					.then(res => res.ok ? res.json() : [])
+					.then(shapes => {
+						if (!Array.isArray(shapes)) return;
+						const canvasEl = document.getElementById('canvas-content');
+						if (!canvasEl) return;
+
+						for (const data of shapes) {
+							const el = newShapeElement(data);
+							if (!el) continue;
+
+							// Mark as cross-space shape
+							el.dataset.sourceSpace = layerSpace;
+							el.dataset.sourceLayerId = layerId;
+							el.classList.add('rspace-cross-space-shape');
+
+							// View-only: make non-interactive
+							if (role === 'viewer') {
+								el.style.pointerEvents = 'none';
+								el.style.opacity = '0.8';
+							}
+
+							canvasEl.appendChild(el);
+						}
+					})
+					.catch(() => {
+						console.warn('[Canvas] Failed to load shapes from space layer:', layerSpace);
+					});
+			});
+
+			// Clean up shapes when a space layer is removed
+			document.addEventListener('layer-close', (e) => {
+				const layerId = e.detail?.layerId;
+				if (!layerId) return;
+				document.querySelectorAll(`[data-source-layer-id="${layerId}"]`).forEach(el => el.remove());
+			});
+
 			// ── "Try Demo" button visibility ──
 			// Hide on demo space, show on bare domain
 			(function() {
diff --git a/website/shell.ts b/website/shell.ts
index a122744..57d4943 100644
--- a/website/shell.ts
+++ b/website/shell.ts
@@ -42,6 +42,21 @@ const spaceSlug = document.body?.getAttribute("data-space-slug");
 if (spaceSlug && spaceSlug !== "demo") {
 	const runtime = new RSpaceOfflineRuntime(spaceSlug);
 	(window as any).__rspaceOfflineRuntime = runtime;
+
+	// Configure module scope resolution from server-rendered data
+	try {
+		const scopeJson = document.body?.getAttribute("data-scope-overrides");
+		const overrides: Record<string, string> = scopeJson ? JSON.parse(scopeJson) : {};
+		// Build scope config: merge module defaults with space overrides
+		const moduleList: Array<{ id: string; scoping?: { defaultScope: string } }> =
+			(window as any).__rspaceModuleList || [];
+		const scopes: Array<{ id: string; scope: 'global' | 'space' }> = moduleList.map(m => ({
+			id: m.id,
+			scope: (overrides[m.id] || m.scoping?.defaultScope || 'space') as 'global' | 'space',
+		}));
+		runtime.setModuleScopes(scopes);
+	} catch { /* scope config unavailable — defaults to space-scoped */ }
+
 	runtime.init().catch((e: unknown) => {
 		console.warn("[shell] Offline runtime init failed — REST fallback only:", e);
 	});