diff --git a/docker-compose.dev-sx-host.yml b/docker-compose.dev-sx-host.yml
index 394831fc..f5fee2cd 100644
--- a/docker-compose.dev-sx-host.yml
+++ b/docker-compose.dev-sx-host.yml
@@ -108,6 +108,8 @@ services:
       SX_ACTOR: "events.rose-ash.com"
       SX_SELF_URL: "http://sx_events:8000"
       SX_FED_SECRET: "rose-ash-fed-2026-shared-a3f9"
+      # Cross-domain: where to place ticket orders (the shop peer).
+      SX_SHOP_BASE: "http://sx_shop:8000"
     volumes:
       - ./spec:/app/spec:ro
       - ./lib:/app/lib:ro
@@ -122,6 +124,41 @@ services:
       - default
     restart: unless-stopped
 
+  # The SHOP domain — a fed-sx peer running lib/host with SX_DOMAIN=shop (an "order" type). Events
+  # places ticket orders here (POST /order). Replaces the Python shop/market service.
+  sx_shop:
+    image: registry.rose-ash.com:5000/sx_docs:latest
+    container_name: sx-dev-sx_shop-1
+    entrypoint: ["bash", "/app/lib/host/serve.sh"]
+    working_dir: /app
+    environment:
+      SX_PROJECT_DIR: /app
+      SX_SERVER: /app/bin/sx_server
+      HOST_PORT: "8000"
+      SX_HTTP_HOST: "0.0.0.0"
+      SX_PERSIST_DIR: /data/persist
+      SX_ADMIN_USER: admin
+      SX_ADMIN_PASSWORD: "sx-shop-camper-2026"
+      SX_SESSION_SECRET: "shop-sess-9d2e1f"
+      SX_SERVING_JIT: "1"
+      OCAMLRUNPARAM: "b"
+      SX_DOMAIN: "shop"
+      SX_ACTOR: "shop.rose-ash.com"
+      SX_SELF_URL: "http://sx_shop:8000"
+      SX_FED_SECRET: "rose-ash-fed-2026-shared-a3f9"
+    volumes:
+      - ./spec:/app/spec:ro
+      - ./lib:/app/lib:ro
+      - ./next:/app/next:ro
+      - ./web:/app/web:ro
+      - ./shared/static:/app/shared/static:ro
+      - ./hosts/ocaml/_build/default/bin/sx_server.exe:/app/bin/sx_server:ro
+      - /root/sx-shop-persist:/data/persist
+    networks:
+      - externalnet
+      - default
+    restart: unless-stopped
+
 networks:
   externalnet:
     external: true
diff --git a/lib/host/blog.sx b/lib/host/blog.sx
index 595d727a..e8283d52 100644
--- a/lib/host/blog.sx
+++ b/lib/host/blog.sx
@@ -152,6 +152,14 @@
 ;; It federates to events, whose calendar type declares an on-allocate behavior that links it.
 (define host/blog--events-base "")         ;; the events peer base URL (serve-set from SX_EVENTS_BASE)
 (define host/blog--set-events-base! (fn (b) (set! host/blog--events-base b)))
+(define host/blog--shop-base "")           ;; the shop peer base URL (serve-set from SX_SHOP_BASE)
+(define host/blog--set-shop-base! (fn (b) (set! host/blog--shop-base b)))
+;; buy a ticket for an event: a directed cross-domain call to the shop (POST /order/<event>) that
+;; creates an order and returns "order:<id>"; we then link event--sold-->order. (Synchronous cross-
+;; domain call, like the RA kernel — not everything is a federated activity; directed reads/writes
+;; are fine.)
+(define host/blog--http-order
+  (fn (event) (get (http-request "POST" (str host/blog--shop-base "/order?event=" event) {} "") "body")))
 (define host/blog--allocate-activity
   (fn (post calendar)
     {:verb "allocate" :actor host/blog--actor
@@ -580,6 +588,13 @@
                   (if (and (= (get e :src) slug) (= (get e :kind) kind))
                     (concat acc (list (get e :dst))) acc))
           (list) (host/blog--all-edges))))))
+;; unfiltered outgoing edges — includes CROSS-DOMAIN targets (a post/order on another peer, which
+;; isn't a local slug so host/blog-out would drop it). Used for federated links (allocated, sold).
+(define host/blog--out-raw
+  (fn (slug kind)
+    (reduce (fn (acc e)
+              (if (and (= (get e :src) slug) (= (get e :kind) kind)) (concat acc (list (get e :dst))) acc))
+      (list) (host/blog--all-edges))))
 (define host/blog-in
   (fn (slug kind)
     (let ((existing (host/blog-slugs)))
@@ -2981,21 +2996,77 @@
                                        (unquote (if (> (len (get e "args")) 0) (str (first (get e "args"))) "")))))
                        host/blog--flow-log))))))))))))
 
-;; ── /calendars — the events domain view: posts allocated to each calendar (federated from blog) ──
+;; the scheduled events on a calendar, each with its linked post + a Buy-ticket form (→ shop).
+(define host/blog--events-list
+  (fn (calendar)
+    (let ((events (host/blog-out calendar "scheduled")))
+      (if (= (len events) 0) (quote (p :style "color:#999" (em "No events scheduled.")))
+        (cons (quote ul)
+          (map (fn (ev)
+                 (let ((features (host/blog--out-raw ev "features")) (sold (host/blog--out-raw ev "sold")))
+                   (quasiquote (li :style "margin:0.3em 0"
+                     (b (unquote (str ev)))
+                     (unquote (if (> (len features) 0) (str " · features: " (first features)) ""))
+                     (unquote (str " · tickets sold: " (str (len sold)) " "))
+                     (form :method "post" :action (unquote (str "/buy?event=" ev)) :style "display:inline"
+                       (button :type "submit" "🎟 Buy ticket"))))))
+               events))))))
+;; events: schedule an event on the main calendar, optionally featuring a (blog-allocated) post.
+(define host/blog-new-event
+  (fn (req)
+    (let ((title (host/field req "title")) (date (or (host/field req "date") "")) (post (or (host/field req "post") "")))
+      (begin
+        (when (and title (not (= title "")))
+          (let ((slug (host/blog-slugify title)))
+            (begin
+              (host/blog-put! slug title (str "(article (h1 \"" title "\") (p \"" date "\"))") "published")
+              (host/blog-relate! slug "event" "is-a")
+              (host/blog-relate! "main" slug "scheduled")
+              (when (not (= post "")) (host/blog-relate! slug post "features")))))
+        (dream-redirect "/calendars")))))
+;; events: buy a ticket for an event — a cross-domain order on the shop, then link event--sold-->order.
+(define host/blog-buy
+  (fn (req)
+    (let ((event (or (dream-query-param req "event") (host/field req "event") "")))
+      (begin
+        (when (and (not (= event "")) (not (= host/blog--shop-base "")))
+          (let ((body (host/blog--http-order event)))
+            (when (starts-with? body "order:")
+              (host/blog-relate! event (substr body 6 (- (len body) 6)) "sold"))))
+        (dream-redirect "/calendars")))))
+;; shop: create an order for an event (an order post is-a order, related to the event) → "order:<id>".
+(define host/blog-order
+  (fn (req)
+    (let ((event (or (dream-query-param req "event") "unknown")))
+      (let ((oid (str "order-" event "-" (str (len (host/blog-slugs))))))
+        (begin
+          (host/blog-put! oid (str "Order: " event) (str "(article (h1 \"Order\") (p \"" event "\"))") "published")
+          (host/blog-relate! oid "order" "is-a")
+          (host/blog-relate! oid event "for")
+          (dream-response 200 {:content-type "text/plain; charset=utf-8"} (str "order:" oid)))))))
+;; ── /calendars — the events domain view: allocated posts + scheduled events + a create form ──
 (define host/blog-calendars
   (fn (req)
     (host/blog--resp req 200
       (host/blog--page req "Calendars"
         (quasiquote
-          (div (h1 "Calendars")
-            (p "Posts allocated to a calendar (federated in from blog, linked by the calendar type's on-allocate behavior).")
-            (h3 :style "margin:1em 0 0.3em" "main")
+          (div (h1 "📅 Calendars (events domain)")
+            (p "Posts allocated in from blog, events scheduled on each calendar, and ticket sales.")
+            (h3 :style "margin:1em 0 0.2em" "main")
+            (h4 :style "margin:0.6em 0 0.2em;font-size:0.95em" "Allocated posts")
             (unquote
-              (let ((posts (host/blog-out "main" "allocated")))
-                (if (= (len posts) 0)
-                  (quote (p :style "color:#999" (em "Nothing allocated yet.")))
-                  (cons (quote ul)
-                    (map (fn (p) (quasiquote (li (unquote (str p))))) posts)))))))))))
+              (let ((posts (host/blog--out-raw "main" "allocated")))
+                (if (= (len posts) 0) (quote (p :style "color:#999" (em "Nothing allocated yet.")))
+                  (cons (quote ul) (map (fn (p) (quasiquote (li (unquote (str p))))) posts)))))
+            (h4 :style "margin:0.6em 0 0.2em;font-size:0.95em" "Scheduled events")
+            (unquote (host/blog--events-list "main"))
+            (h4 :style "margin:0.8em 0 0.2em;font-size:0.95em" "Schedule an event")
+            (form :method "post" :action "/new-event"
+                  :style "padding:0.6em;border:1px dashed #bbb;background:#fafafa;font-size:0.9em"
+              (input :name "title" :placeholder "Event title" :style "width:12em") " "
+              (input :name "date" :placeholder "date" :style "width:7em") " "
+              (input :name "post" :placeholder "features post (slug)" :style "width:11em") " "
+              (button :type "submit" "Create event"))))))))
 
 ;; ── /activities — P2: the EVENT SOURCE ───────────────────────────────
 ;; Every observable state change emitted as a canonical activity (Create/Update on content,
@@ -3052,6 +3123,9 @@
     (dream-get "/flows" host/blog-flows)
     (dream-get "/fed-tick" host/blog-fed-tick)
     (dream-get "/calendars" host/blog-calendars)
+    (dream-post "/new-event" host/blog-new-event)
+    (dream-post "/buy" host/blog-buy)
+    (dream-post "/order" host/blog-order)
     (dream-get "/activities" host/blog-activities)
     (dream-get "/:slug/source" host/blog-source)
     (dream-get "/:slug/relate-options" host/blog-relate-options)
diff --git a/lib/host/serve.sh b/lib/host/serve.sh
index 73ffac04..e56bc643 100755
--- a/lib/host/serve.sh
+++ b/lib/host/serve.sh
@@ -243,6 +243,18 @@ EPOCH=1
     echo "(epoch $EPOCH)"
     echo "(eval \"(host/blog--set-type-behavior! \\\"calendar\\\" (list {\\\"verb\\\" \\\"allocate\\\" \\\"type\\\" \\\"article\\\" \\\"dag\\\" \\\"allocate-link\\\"}))\")"
     EPOCH=$((EPOCH+1))
+    # an "event" type (events scheduled on a calendar); point at the shop peer for ticket orders.
+    echo "(epoch $EPOCH)"
+    echo "(eval \"(host/blog-seed! \\\"event\\\" \\\"Event\\\" \\\"(article (h1 \\\\\\\"Event\\\\\\\"))\\\" \\\"published\\\")\")"
+    EPOCH=$((EPOCH+1))
+    echo "(epoch $EPOCH)"
+    echo "(eval \"(host/blog--set-shop-base! \\\"${SX_SHOP_BASE:-}\\\")\")"
+    EPOCH=$((EPOCH+1))
+  elif [ "${SX_DOMAIN:-blog}" = "shop" ]; then
+    # The SHOP domain: an "order" type. POST /order?event= creates an order (is-a order) for an event.
+    echo "(epoch $EPOCH)"
+    echo "(eval \"(host/blog-seed! \\\"order\\\" \\\"Order\\\" \\\"(article (h1 \\\\\\\"Order\\\\\\\"))\\\" \\\"published\\\")\")"
+    EPOCH=$((EPOCH+1))
   else
     # The BLOG domain: article create→publish (sync) + update→blog-digest (durable kernel) + a
     # "category" field for the edit form; and point at the events peer for cross-domain allocate.