diff --git a/common/src/app/common/render_wasm/serialize_shape.cljs b/common/src/app/common/render_wasm/serialize_shape.cljs
index 868c0321f5..07ce3697ab 100644
--- a/common/src/app/common/render_wasm/serialize_shape.cljs
+++ b/common/src/app/common/render_wasm/serialize_shape.cljs
@@ -25,16 +25,52 @@
   dispatching per changed key through the same underlying `props` setters."
   (:require
    [app.common.render-wasm.api.props :as props]
-   [app.common.render-wasm.api.upload :as upload]))
+   [app.common.render-wasm.api.upload :as upload]
+   [app.common.render-wasm.svg-derived :as svg-derived]))
+
+(defn needs-shape-tail?
+  "True when `shape` needs the per-shape svg-attrs/path tail after a
+  structural upload: svg-attrs present, or `:path`/`:bool` with content."
+  [shape]
+  (let [type (:type shape)]
+    (or (some? (:svg-attrs shape))
+        (and (contains? #{:path :bool} type)
+             (some? (:content shape))))))
+
+(defn- write-shape-tail!
+  "Per-shape svg-attrs/path tail after a structural upload."
+  [shape]
+  (when (some? (:svg-attrs shape))
+    (props/set-shape-svg-attrs (:svg-attrs shape)))
+
+  (let [type (:type shape)]
+    (when (and (contains? #{:path :bool} type) (some? (:content shape)))
+      (props/set-shape-path-content (:content shape)))))
 
 (defn serialize-shape!
   "Applies every host-independent WASM property of `shape`."
   [shape]
-  (let [type (get shape :type)]
+  (let [shape (svg-derived/apply-svg-derived shape)]
     (upload/set-shape-upload! shape {:include-layout? false})
 
-    (when (some? (get shape :svg-attrs))
-      (props/set-shape-svg-attrs (get shape :svg-attrs)))
+    (when (needs-shape-tail? shape)
+      (write-shape-tail! shape))
 
-    (when (and (contains? #{:path :bool} type) (some? (get shape :content)))
-      (props/set-shape-path-content (get shape :content)))))
+    shape))
+
+(defn serialize-shapes-batch!
+  "Structural batch upload plus per-shape svg-attrs/path tail.
+
+  Derives via svg-derived, uploads one `_set_shapes_batch` with `opts`,
+  then selects each shape needing svg-attrs/path content and applies it.
+  Host text/grid/image sequencing stays in callers. Returns the prepared
+  vector for the downstream host-attrs loop."
+  [shapes opts select-fn]
+  (let [prepared (mapv svg-derived/apply-svg-derived shapes)]
+    (when (seq prepared)
+      (upload/flush-shapes-batch! prepared opts)
+      (doseq [shape prepared]
+        (when (needs-shape-tail? shape)
+          (select-fn (:id shape))
+          (write-shape-tail! shape))))
+    prepared))
diff --git a/frontend/src/app/render_wasm/svg_fills.cljs b/common/src/app/common/render_wasm/svg_derived.cljs
similarity index 80%
rename from frontend/src/app/render_wasm/svg_fills.cljs
rename to common/src/app/common/render_wasm/svg_derived.cljs
index 829612bb2b..314f91f195 100644
--- a/frontend/src/app/render_wasm/svg_fills.cljs
+++ b/common/src/app/common/render_wasm/svg_derived.cljs
@@ -4,7 +4,8 @@
 ;;
 ;; Copyright (c) KALEIDOS SUBSIDIARY SL
 
-(ns app.render-wasm.svg-fills
+(ns app.common.render-wasm.svg-derived
+  "SVG-derived WASM attrs (fills, blur, shadows), shared by frontend and export"
   (:require
    [app.common.data :as d]
    [app.common.data.macros :as dm]
@@ -12,6 +13,7 @@
    [app.common.geom.rect :as grc]
    [app.common.svg :as csvg]
    [app.common.types.color :as clr]
+   [app.common.uuid :as uuid]
    [clojure.string :as str]))
 
 (def ^:private url-fill-pattern
@@ -380,3 +382,86 @@
       [{:fill-color "#000000" :fill-opacity 1}]
       :else [])))
 
+(def ^:private drop-shadow-tags
+  #{:feOffset :feGaussianBlur :feColorMatrix})
+
+(defn- find-filter-element
+  "Finds a filter element by tag in filter content."
+  [filter-content tag]
+  (some #(when (= tag (:tag %)) %) filter-content))
+
+(defn- find-filter-def
+  [shape]
+  (let [filter-attr (or (dm/get-in shape [:svg-attrs :filter])
+                        (dm/get-in shape [:svg-attrs :style :filter]))
+        svg-defs    (dm/get-prop shape :svg-defs)]
+    (when (and filter-attr svg-defs)
+      (let [filter-ids (csvg/extract-ids filter-attr)]
+        (some #(get svg-defs %) filter-ids)))))
+
+(defn- build-blur
+  [gaussian-blur]
+  (when gaussian-blur
+    {:id (uuid/next)
+     :type :layer-blur
+     ;; For layer blur the value matches stdDeviation directly
+     :value (-> (dm/get-in gaussian-blur [:attrs :stdDeviation])
+                (d/parse-double 0))
+     :hidden false}))
+
+(defn- build-drop-shadow
+  [filter-content drop-shadow-elements]
+  (let [offset-elem (find-filter-element filter-content :feOffset)]
+    (when (and offset-elem (seq drop-shadow-elements))
+      (let [blur-elem  (find-filter-element drop-shadow-elements :feGaussianBlur)
+            dx         (-> (dm/get-in offset-elem [:attrs :dx])
+                           (d/parse-double 0))
+            dy         (-> (dm/get-in offset-elem [:attrs :dy])
+                           (d/parse-double 0))
+            blur-value (if blur-elem
+                         (-> (dm/get-in blur-elem [:attrs :stdDeviation])
+                             (d/parse-double 0)
+                             (* 2))
+                         0)]
+        [{:id (uuid/next)
+          :style :drop-shadow
+          :offset-x dx
+          :offset-y dy
+          :blur blur-value
+          :spread 0
+          :hidden false
+          ;; TODO: parse feColorMatrix to extract color/opacity
+          :color {:color "#000000" :opacity 1}}]))))
+
+(defn apply-svg-filters
+  "Derives native blur/shadow from SVG filter definitions when the shape does
+  not already have them. The SVG attributes are left untouched so SVG fallback
+  rendering keeps working the same way as gradient fills."
+  [shape]
+  (let [existing-blur   (:blur shape)
+        existing-shadow (:shadow shape)]
+    (if-let [filter-def (find-filter-def shape)]
+      (let [content              (:content filter-def)
+            gaussian-blur        (find-filter-element content :feGaussianBlur)
+            drop-shadow-elements (filter #(contains? drop-shadow-tags (:tag %)) content)
+            blur                 (or existing-blur (build-blur gaussian-blur))
+            shadow               (if (seq existing-shadow)
+                                   existing-shadow
+                                   (build-drop-shadow content drop-shadow-elements))]
+        (cond-> shape
+          blur (assoc :blur blur)
+          (seq shadow) (assoc :shadow shadow)))
+      shape)))
+
+(defn apply-svg-derived
+  "Applies SVG-derived effects (fills, blur, shadows) uniformly.
+  - Keeps user fills if present; otherwise derives from SVG.
+  - Converts SVG filters into native blur/shadow when needed.
+  - Always returns shape with :fills (possibly []) and blur/shadow keys."
+  [shape]
+  (let [shape' (apply-svg-filters shape)
+        fills  (or (resolve-shape-fills shape') [])]
+    (assoc shape'
+           :fills fills
+           :blur (:blur shape')
+           :shadow (:shadow shape'))))
diff --git a/exporter/scripts/test b/exporter/scripts/test
index 169cdc8a9e..040341ed26 100755
--- a/exporter/scripts/test
+++ b/exporter/scripts/test
@@ -2,4 +2,7 @@
 
 set -ex
 pnpm install;
+pushd ../render-wasm;
+./build export;
+popd
 pnpm run test;
diff --git a/exporter/src/app/wasm/serialize.cljs b/exporter/src/app/wasm/serialize.cljs
index f3edb39a6a..6f316187c7 100644
--- a/exporter/src/app/wasm/serialize.cljs
+++ b/exporter/src/app/wasm/serialize.cljs
@@ -28,13 +28,13 @@
   host-specific parts are handled here: fills/strokes (image bytes are provisioned
   separately) and text content (fonts provisioned separately)."
   [shape]
-  (let [type (get shape :type)]
-    (serialize-shape/serialize-shape! shape)
-    (props/write-shape-fills! (get shape :fills))
+  (let [prepared (serialize-shape/serialize-shape! shape)
+        type (:type prepared)]
+    (props/write-shape-fills! (:fills prepared))
     (when-not (= type :group)
-      (props/write-shape-strokes! (get shape :strokes)))
+      (props/write-shape-strokes! (:strokes prepared)))
     (when (= type :text)
-      (text/set-shape-text! (get shape :content)))))
+      (text/set-shape-text! (:content prepared)))))
 
 (defn serialize-scene!
   "Loads every shape of an `objects` map into the WASM design state. Resets the
diff --git a/exporter/test/exporter_tests/renderer_svg_test.cljs b/exporter/test/exporter_tests/renderer_svg_test.cljs
index 3c841a2d77..7d6bd68899 100644
--- a/exporter/test/exporter_tests/renderer_svg_test.cljs
+++ b/exporter/test/exporter_tests/renderer_svg_test.cljs
@@ -7,7 +7,11 @@
 (ns exporter-tests.renderer-svg-test
   (:require
    [app.renderer.svg-gradient :as svg-gradient]
-   [cljs.test :refer [deftest is testing]]))
+   [app.wasm :as wasm-io]
+   [app.wasm.serialize :as serialize]
+   [cljs.test :refer [deftest is testing async]]
+   [clojure.string :as str]
+   [promesa.core :as p]))
 
 (def gradient-stops
   [{"color" "#000000" "offset" 0 "opacity" 1}
@@ -23,3 +27,46 @@
                                        "stops" gradient-stops}}
             result         (svg-gradient/data->gradient-def "text-id" ["#000001" gradient-data])]
         (is (= element-name (get result "name")))))))
+
+
+(def ^:private svg-red-id (random-uuid))
+(def ^:private blue-id (random-uuid))
+
+(defn- scene []
+  {svg-red-id {:id svg-red-id
+               :type :rect
+               :name "svg-red"
+               :x 10 :y 10 :width 100 :height 100
+               :rotation 0
+               :selrect {:x 10 :y 10 :x1 10 :y1 10 :x2 110 :y2 110
+                         :width 100 :height 100}
+               :strokes []
+               :svg-attrs {:fill "#ff0000"}}
+   blue-id {:id blue-id
+            :type :rect
+            :name "user-blue"
+            :x 130 :y 10 :width 100 :height 100
+            :rotation 0
+            :selrect {:x 130 :y 10 :x1 130 :y1 10 :x2 230 :y2 110
+                      :width 100 :height 100}
+            :strokes []
+            :fills [{:fill-color "#0000ff" :fill-opacity 1}]}})
+
+(defn- render-svg-string
+  [shape-id]
+  (.toString (js/Buffer.from (wasm-io/render-shape-svg shape-id 1))))
+
+(deftest exporter-honours-svg-attr-fills
+  (async done
+    (->> (wasm-io/init!)
+         (p/mcat
+          (fn [_]
+            (serialize/serialize-scene! (scene))
+            (let [red (render-svg-string svg-red-id)
+                  blue (render-svg-string blue-id)]
+              (is (str/includes? blue "blue")
+                  "control: user fills render, so the harness works")
+              (is (str/includes? red "fill=\"red\"")
+                  "svg-attr fill survives headless serialization")
+              (p/resolved nil))))
+         (p/mcat (fn [_] (done))))))
diff --git a/frontend/src/app/main/data/workspace/path/edition.cljs b/frontend/src/app/main/data/workspace/path/edition.cljs
index 5e0f9f8c24..dcd40d6962 100644
--- a/frontend/src/app/main/data/workspace/path/edition.cljs
+++ b/frontend/src/app/main/data/workspace/path/edition.cljs
@@ -10,6 +10,7 @@
    [app.common.data.macros :as dm]
    [app.common.files.helpers :as cfh]
    [app.common.geom.point :as gpt]
+   [app.common.render-wasm.svg-derived :as svg-derived]
    [app.common.types.path :as path]
    [app.common.types.path.helpers :as path.helpers]
    [app.main.data.helpers :as dsh]
@@ -22,7 +23,6 @@
    [app.main.data.workspace.path.tools :as tools]
    [app.main.data.workspace.path.undo :as undo]
    [app.main.streams :as ms]
-   [app.render-wasm.svg-fills :as svg-fills]
    [app.util.mouse :as mse]
    [beicon.v2.core :as rx]
    [beicon.v2.operators :as rxo]
@@ -885,7 +885,7 @@
   "Resolves the fills inherited by the editing copy.
   Frames stop group fill inheritance."
   [shape objects]
-  (let [own (svg-fills/resolve-shape-fills shape)]
+  (let [own (svg-derived/resolve-shape-fills shape)]
     (if (seq own)
       own
       (loop [parent-id (:parent-id shape)
@@ -897,7 +897,7 @@
           (let [parent (get objects parent-id)]
             (cond
               (nil? parent)             []
-              (cfh/group-shape? parent) (let [fills (svg-fills/resolve-shape-fills parent)]
+              (cfh/group-shape? parent) (let [fills (svg-derived/resolve-shape-fills parent)]
                                           (if (seq fills)
                                             fills
                                             (recur (:parent-id parent)
diff --git a/frontend/src/app/render_wasm/api.cljs b/frontend/src/app/render_wasm/api.cljs
index 8cfda5e150..0c5a4c3d0b 100644
--- a/frontend/src/app/render_wasm/api.cljs
+++ b/frontend/src/app/render_wasm/api.cljs
@@ -17,7 +17,6 @@
    [app.common.logging :as log]
    [app.common.math :as mth]
    [app.common.render-wasm.api.props :as props]
-   [app.common.render-wasm.api.upload :as upload]
    [app.common.render-wasm.helpers :as h]
    [app.common.render-wasm.mem :as mem]
    [app.common.render-wasm.mem.heap32 :as mem.h32]
@@ -50,7 +49,6 @@
    [app.render-wasm.gesture :as wasm-gesture]
    [app.render-wasm.performance :as perf]
    [app.render-wasm.rulers-state :as rulers-state]
-   [app.render-wasm.svg-filters :as svg-filters]
    [app.render-wasm.text-editor :as text-editor]
    [app.util.debug :as dbg]
    [app.util.dom :as dom]
@@ -1645,11 +1643,10 @@
     {:thumbnails [] :full [] :font-face-keys #{} :pending-font-face-keys #{}}
     (do
       (perf/begin-measure "set-object")
-      (let [shape (svg-filters/apply-svg-derived shape)]
-        (serialize-shape/serialize-shape! shape)
-        (let [result (set-object-host-attrs shape false)]
-          (perf/end-measure "set-object")
-          result)))))
+      (let [prepared (serialize-shape/serialize-shape! shape)
+            result (set-object-host-attrs prepared false)]
+        (perf/end-measure "set-object")
+        result))))
 
 (defn- update-text-layouts
   "Synchronously update text layouts for all shapes and send rect updates
@@ -1814,24 +1811,11 @@
         end-index (min total (+ start-index BATCH_MAX_SHAPES))
         chunk     (into [] (subvec (if (vector? shapes) shapes (vec shapes))
                                    start-index end-index))
-        prepared  (mapv svg-filters/apply-svg-derived chunk)]
-
-    ;; One multi-shape structural upload (base+children+blur+shadows+flex+item+fills+strokes).
-    (when (seq prepared)
-      (upload/flush-shapes-batch! prepared {:include-layout? true
-                                            :include-fills-strokes? true}))
-
-    ;; Path + svg-attrs still need the legacy per-shape path (variable/large).
-    (doseq [shape prepared]
-      (let [id   (dm/get-prop shape :id)
-            type (dm/get-prop shape :type)]
-        (when (or (some? (get shape :svg-attrs))
-                  (and (contains? #{:path :bool} type) (some? (get shape :content))))
-          (use-shape id)
-          (when (some? (get shape :svg-attrs))
-            (props/set-shape-svg-attrs (get shape :svg-attrs)))
-          (when (and (contains? #{:path :bool} type) (some? (get shape :content)))
-            (props/set-shape-path-content (get shape :content))))))
+        prepared  (serialize-shape/serialize-shapes-batch!
+                   chunk
+                   {:include-layout? true
+                    :include-fills-strokes? true}
+                   use-shape)]
 
     (loop [xs prepared
            t-acc (transient thumbnails-acc)
@@ -1977,53 +1961,44 @@
 (defn- set-objects-sync
   "Synchronously process all shapes (for small shape counts)."
   [shapes render-callback on-shapes-ready]
-  (let [prepared (mapv svg-filters/apply-svg-derived shapes)]
-    (when (seq prepared)
-      (upload/flush-shapes-batch! prepared {:include-layout? true
-                                            :include-fills-strokes? true}))
-    (doseq [shape prepared]
-      (let [id   (dm/get-prop shape :id)
-            type (dm/get-prop shape :type)]
-        (when (or (some? (get shape :svg-attrs))
-                  (and (contains? #{:path :bool} type) (some? (get shape :content))))
-          (use-shape id)
-          (when (some? (get shape :svg-attrs))
-            (props/set-shape-svg-attrs (get shape :svg-attrs)))
-          (when (and (contains? #{:path :bool} type) (some? (get shape :content)))
-            (props/set-shape-path-content (get shape :content))))))
-    (let [total-shapes (count prepared)
-          {:keys [thumbnails full text-font-state]}
-          (loop [index 0
-                 thumbnails-acc (transient [])
-                 full-acc (transient [])
-                 font-state-acc empty-text-font-state]
-            (if (< index total-shapes)
-              (let [shape (nth prepared index)
-                    {:keys [thumbnails full font-face-keys pending-font-face-keys]}
-                    (set-object-host-attrs shape true :skip-fills-strokes? true)]
-                (recur (inc index)
-                       (reduce conj! thumbnails-acc thumbnails)
-                       (reduce conj! full-acc full)
-                       (acc-text-font-state font-state-acc
-                                            (:id shape)
-                                            font-face-keys
-                                            pending-font-face-keys)))
-              {:thumbnails (persistent! thumbnails-acc)
-               :full (persistent! full-acc)
-               :text-font-state font-state-acc}))]
-      (perf/end-measure "set-objects")
-      (when on-shapes-ready (on-shapes-ready))
-      (when (wasm/live?)
-        ;; Rebuild the tile index so _render knows which shapes
-        ;; map to which tiles after a page switch.
-        (h/call wasm/internal-module "_set_view_end")
-        (reset! view-interaction-active? false)
-        (process-pending shapes thumbnails full text-font-state
-                         (fn []
-                           (if render-callback
-                             (render-callback)
-                             (request-render "set-objects-sync-complete"))
-                           (ug/dispatch! (ug/event "penpot:wasm:set-objects"))))))))
+  (let [prepared     (serialize-shape/serialize-shapes-batch!
+                      shapes
+                      {:include-layout? true
+                       :include-fills-strokes? true}
+                      use-shape)
+        total-shapes (count prepared)
+        {:keys [thumbnails full text-font-state]}
+        (loop [index 0
+               thumbnails-acc (transient [])
+               full-acc (transient [])
+               font-state-acc empty-text-font-state]
+          (if (< index total-shapes)
+            (let [shape (nth prepared index)
+                  {:keys [thumbnails full font-face-keys pending-font-face-keys]}
+                  (set-object-host-attrs shape true :skip-fills-strokes? true)]
+              (recur (inc index)
+                     (reduce conj! thumbnails-acc thumbnails)
+                     (reduce conj! full-acc full)
+                     (acc-text-font-state font-state-acc
+                                          (:id shape)
+                                          font-face-keys
+                                          pending-font-face-keys)))
+            {:thumbnails (persistent! thumbnails-acc)
+             :full (persistent! full-acc)
+             :text-font-state font-state-acc}))]
+    (perf/end-measure "set-objects")
+    (when on-shapes-ready (on-shapes-ready))
+    (when (wasm/live?)
+      ;; Rebuild the tile index so _render knows which shapes
+      ;; map to which tiles after a page switch.
+      (h/call wasm/internal-module "_set_view_end")
+      (reset! view-interaction-active? false)
+      (process-pending shapes thumbnails full text-font-state
+                       (fn []
+                         (if render-callback
+                           (render-callback)
+                           (request-render "set-objects-sync-complete"))
+                         (ug/dispatch! (ug/event "penpot:wasm:set-objects")))))))
 
 (defn- shapes-in-tree-order
   "Returns shapes sorted in tree order (parents before children).
diff --git a/frontend/src/app/render_wasm/shape.cljs b/frontend/src/app/render_wasm/shape.cljs
index e3cad1058e..995ea816cd 100644
--- a/frontend/src/app/render_wasm/shape.cljs
+++ b/frontend/src/app/render_wasm/shape.cljs
@@ -9,12 +9,12 @@
    [app.common.data :as d]
    [app.common.data.macros :as dm]
    [app.common.files.helpers :as cfh]
+   [app.common.render-wasm.svg-derived :as svg-derived]
    [app.common.transit :as t]
    [app.common.types.shape :as shape]
    [app.common.types.shape.layout :as ctl]
    [app.main.refs :as refs]
    [app.render-wasm.api :as api]
-   [app.render-wasm.svg-filters :as svg-filters]
    [beicon.v2.core :as rx]
    [cljs.core :as c]
    [cuerdas.core :as str]))
@@ -130,8 +130,8 @@
   [shape k]
   (when (api/initialized?)
     (let [shape (case k
-                  :svg-attrs (svg-filters/apply-svg-derived (assoc shape :svg-attrs (get shape :svg-attrs)))
-                  (:fills :blur :shadow) (svg-filters/apply-svg-derived shape)
+                  :svg-attrs (svg-derived/apply-svg-derived (assoc shape :svg-attrs (get shape :svg-attrs)))
+                  (:fills :blur :shadow) (svg-derived/apply-svg-derived shape)
                   shape)
           v  (get shape k)
           id (get shape :id)]
diff --git a/frontend/src/app/render_wasm/svg_filters.cljs b/frontend/src/app/render_wasm/svg_filters.cljs
deleted file mode 100644
index 13cc8c00ed..0000000000
--- a/frontend/src/app/render_wasm/svg_filters.cljs
+++ /dev/null
@@ -1,98 +0,0 @@
-;; This Source Code Form is subject to the terms of the Mozilla Public
-;; License, v. 2.0. If a copy of the MPL was not distributed with this
-;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
-;;
-;; Copyright (c) KALEIDOS SUBSIDIARY SL
-
-(ns app.render-wasm.svg-filters
-  (:require
-   [app.common.data :as d]
-   [app.common.data.macros :as dm]
-   [app.common.svg :as csvg]
-   [app.common.uuid :as uuid]
-   [app.render-wasm.svg-fills :as svg-fills]))
-
-(def ^:private drop-shadow-tags
-  #{:feOffset :feGaussianBlur :feColorMatrix})
-
-(defn- find-filter-element
-  "Finds a filter element by tag in filter content."
-  [filter-content tag]
-  (some #(when (= tag (:tag %)) %) filter-content))
-
-(defn- find-filter-def
-  [shape]
-  (let [filter-attr (or (dm/get-in shape [:svg-attrs :filter])
-                        (dm/get-in shape [:svg-attrs :style :filter]))
-        svg-defs    (dm/get-prop shape :svg-defs)]
-    (when (and filter-attr svg-defs)
-      (let [filter-ids (csvg/extract-ids filter-attr)]
-        (some #(get svg-defs %) filter-ids)))))
-
-(defn- build-blur
-  [gaussian-blur]
-  (when gaussian-blur
-    {:id (uuid/next)
-     :type :layer-blur
-     ;; For layer blur the value matches stdDeviation directly
-     :value (-> (dm/get-in gaussian-blur [:attrs :stdDeviation])
-                (d/parse-double 0))
-     :hidden false}))
-
-(defn- build-drop-shadow
-  [filter-content drop-shadow-elements]
-  (let [offset-elem (find-filter-element filter-content :feOffset)]
-    (when (and offset-elem (seq drop-shadow-elements))
-      (let [blur-elem  (find-filter-element drop-shadow-elements :feGaussianBlur)
-            dx         (-> (dm/get-in offset-elem [:attrs :dx])
-                           (d/parse-double 0))
-            dy         (-> (dm/get-in offset-elem [:attrs :dy])
-                           (d/parse-double 0))
-            blur-value (if blur-elem
-                         (-> (dm/get-in blur-elem [:attrs :stdDeviation])
-                             (d/parse-double 0)
-                             (* 2))
-                         0)]
-        [{:id (uuid/next)
-          :style :drop-shadow
-          :offset-x dx
-          :offset-y dy
-          :blur blur-value
-          :spread 0
-          :hidden false
-          ;; TODO: parse feColorMatrix to extract color/opacity
-          :color {:color "#000000" :opacity 1}}]))))
-
-(defn apply-svg-filters
-  "Derives native blur/shadow from SVG filter definitions when the shape does
-  not already have them. The SVG attributes are left untouched so SVG fallback
-  rendering keeps working the same way as gradient fills."
-  [shape]
-  (let [existing-blur   (:blur shape)
-        existing-shadow (:shadow shape)]
-    (if-let [filter-def (find-filter-def shape)]
-      (let [content              (:content filter-def)
-            gaussian-blur        (find-filter-element content :feGaussianBlur)
-            drop-shadow-elements (filter #(contains? drop-shadow-tags (:tag %)) content)
-            blur                 (or existing-blur (build-blur gaussian-blur))
-            shadow               (if (seq existing-shadow)
-                                   existing-shadow
-                                   (build-drop-shadow content drop-shadow-elements))]
-        (cond-> shape
-          blur (assoc :blur blur)
-          (seq shadow) (assoc :shadow shadow)))
-      shape)))
-
-(defn apply-svg-derived
-  "Applies SVG-derived effects (fills, blur, shadows) uniformly.
-  - Keeps user fills if present; otherwise derives from SVG.
-  - Converts SVG filters into native blur/shadow when needed.
-  - Always returns shape with :fills (possibly []) and blur/shadow keys."
-  [shape]
-  (let [shape' (apply-svg-filters shape)
-        fills  (or (svg-fills/resolve-shape-fills shape') [])]
-    (assoc shape'
-           :fills fills
-           :blur (:blur shape')
-           :shadow (:shadow shape'))))
-
diff --git a/frontend/test/frontend_tests/render_wasm/serialization_test.cljs b/frontend/test/frontend_tests/render_wasm/serialization_test.cljs
new file mode 100644
index 0000000000..c067793ab9
--- /dev/null
+++ b/frontend/test/frontend_tests/render_wasm/serialization_test.cljs
@@ -0,0 +1,164 @@
+;; This Source Code Form is subject to the terms of the Mozilla Public
+;; License, v. 2.0. If a copy of the MPL was not distributed with this
+;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;;
+;; Copyright (c) KALEIDOS SUBSIDIARY SL
+
+(ns frontend-tests.render-wasm.serialization-test
+  "Routing tests for `serialize-shape!` and `serialize-shapes-batch!`.
+
+   A shared `tail-cases` table states, per shape, whether the svg-attrs/path
+   tail must fire. The pure `needs-shape-tail?` predicate is tested against
+   the table with no stubs; the two thin routing tests drive both serializers
+   from the same table with the FFI boundary stubbed. Guard drift between the
+   single and batch paths fails loudly. These tests assert routing only;
+   render output below the FFI line needs headed or exporter pixel runs."
+  (:require
+   [app.common.render-wasm.api.props :as props]
+   [app.common.render-wasm.api.upload :as upload]
+   [app.common.render-wasm.serialize-shape :as serialize-shape]
+   [app.common.render-wasm.svg-derived :as svg-derived]
+   [cljs.test :as t :include-macros true]))
+
+(defn- with-ffi-stubs*
+  "Stubs the single-arity FFI boundary fns (`flush-shapes-batch!`,
+  `set-shape-svg-attrs`, `set-shape-path-content`). `set-shape-upload!` is
+  deliberately left real: it is a trivial one-liner over the stubbed flush,
+  so the single test exercises its actual delegation and default opts. A
+  plain fn `set!` onto a multi-arity var breaks under the `:esm` test build
+  (call sites dispatch via `cljs$core$IFn$_invoke$arity$N`; see `mock/stub`)."
+  [stubs thunk]
+  (let [orig-flush     upload/flush-shapes-batch!
+        orig-svg-attrs props/set-shape-svg-attrs
+        orig-path      props/set-shape-path-content]
+    (set! upload/flush-shapes-batch! (:flush stubs))
+    (set! props/set-shape-svg-attrs (:svg-attrs stubs))
+    (set! props/set-shape-path-content (:path stubs))
+    (try
+      (thunk)
+      (finally
+        (set! upload/flush-shapes-batch! orig-flush)
+        (set! props/set-shape-svg-attrs orig-svg-attrs)
+        (set! props/set-shape-path-content orig-path)))))
+
+(def ^:private tail-cases
+  "Shared spec for the svg-attrs/path tail. Each entry states whether the
+  tail must fire (`:tail?`) and which writes it must perform (`:svg?`,
+  `:path?`). Tests for single and batch serialization share this table."
+  [{:shape {:id (random-uuid) :type :frame} :tail? false :svg? false :path? false}
+   {:shape {:id (random-uuid) :type :rect} :tail? false :svg? false :path? false}
+   {:shape {:id (random-uuid) :type :rect :svg-attrs {:fill "blue"}}
+    :tail? true :svg? true :path? false}
+   {:shape {:id (random-uuid) :type :group :svg-attrs {:fill "blue"}}
+    :tail? true :svg? true :path? false}
+   {:shape {:id (random-uuid) :type :text :svg-attrs {:fill "blue"}}
+    :tail? true :svg? true :path? false}
+   {:shape {:id (random-uuid) :type :path :content {:type :path-content}}
+    :tail? true :svg? false :path? true}
+   {:shape {:id (random-uuid) :type :path}
+    :tail? false :svg? false :path? false}
+   {:shape {:id (random-uuid) :type :path
+            :content {:type :path-content} :svg-attrs {:fill "red"}}
+    :tail? true :svg? true :path? true}
+   {:shape {:id (random-uuid) :type :bool :content {:type :bool-content}}
+    :tail? true :svg? false :path? true}
+   {:shape {:id (random-uuid) :type :bool}
+    :tail? false :svg? false :path? false}
+   {:shape {:id (random-uuid) :type :text :content {:type :text-content}}
+    :tail? false :svg? false :path? false}
+   ;; svg-attrs fires the tail, but the inner type guard must still withhold
+   ;; the path write from text content.
+   {:shape {:id (random-uuid) :type :text
+            :svg-attrs {:fill "blue"} :content {:type :text-content}}
+    :tail? true :svg? true :path? false}
+   ;; svg-attrs alone fires the tail for path shapes; the svg write must not
+   ;; hide under the content check.
+   {:shape {:id (random-uuid) :type :path :svg-attrs {:fill "red"}}
+    :tail? true :svg? true :path? false}])
+
+(defn- expected-events
+  [cases]
+  (into []
+        (mapcat (fn [{:keys [shape tail? svg? path?]}]
+                  (let [id (:id shape)]
+                    (cond-> []
+                      tail? (conj [:select id])
+                      svg?  (conj [:svg-attrs id (:svg-attrs shape)])
+                      path? (conj [:path id (:content shape)])))))
+        cases))
+
+(t/deftest tail-cases-flags-are-consistent
+  (doseq [{:keys [shape tail? svg? path?]} tail-cases]
+    (t/is (boolean? tail?) "tail? is a boolean")
+    (t/is (= tail? (boolean (or svg? path?))) "tail? matches the write flags")
+    (t/is (= svg? (some? (:svg-attrs shape))) "svg? matches the shape")
+    (t/is (= path? (boolean (and (contains? #{:path :bool} (:type shape))
+                                 (some? (:content shape)))))
+          "path? matches the shape")))
+
+(t/deftest needs-shape-tail-matches-spec-table
+  (doseq [{:keys [shape tail?]} tail-cases]
+    (t/is (= tail? (serialize-shape/needs-shape-tail? shape))
+          (str "predicate matches spec for " (:type shape)
+               " svg? " (some? (:svg-attrs shape))
+               " content? " (some? (:content shape))))))
+
+(t/deftest serialize-shapes-batch-routes-flush-and-tail
+  (let [shapes (mapv :shape tail-cases)
+        opts {:include-layout? true :include-fills-strokes? true}
+        flush-calls (atom [])
+        events (atom [])
+        current (atom nil)
+        select-fn (fn [id]
+                    (reset! current id)
+                    (swap! events conj [:select id]))
+        stubs {:flush (fn [s o] (swap! flush-calls conj {:shapes s :opts o}) nil)
+               :svg-attrs (fn [attrs] (swap! events conj [:svg-attrs @current attrs]) nil)
+               :path (fn [content] (swap! events conj [:path @current content]) nil)}
+        result (with-ffi-stubs* stubs
+                 #(serialize-shape/serialize-shapes-batch! shapes opts select-fn))
+        flushed (first @flush-calls)]
+    (t/is (= 1 (count @flush-calls)) "exactly one flush")
+    (t/is (= opts (:opts flushed)) "flush carries passed opts")
+    (t/is (= (count shapes) (count (:shapes flushed))) "flush covers all shapes")
+    (t/is (= (mapv :id shapes) (mapv :id (:shapes flushed))) "order preserved")
+    (t/is (= (expected-events tail-cases) @events)
+          "select precedes each tail write, tails hit the right ids")
+    (t/is (= (mapv :id shapes) (mapv :id result)) "returns prepared in order")))
+
+(t/deftest serialize-shape-routes-single-upload-and-tail
+  (doseq [{:keys [shape tail? svg? path?]} tail-cases]
+    (let [flush-calls (atom [])
+          svg-applied (atom [])
+          path-applied (atom [])
+          stubs {:flush (fn [s o] (swap! flush-calls conj {:shapes s :opts o}) nil)
+                 :svg-attrs (fn [attrs] (swap! svg-applied conj attrs) nil)
+                 :path (fn [content] (swap! path-applied conj content) nil)}]
+      (let [expected (svg-derived/apply-svg-derived shape)
+            result (with-ffi-stubs* stubs #(serialize-shape/serialize-shape! shape))]
+        (t/is (= [{:shapes [expected] :opts {:include-layout? false}}] @flush-calls)
+              (str "single upload carries derived shape without layout for " (:type shape)))
+        (t/is (= expected result)
+              (str "returns the derived shape for downstream host attrs for " (:type shape))))
+      (t/is (= (if svg? [(:svg-attrs shape)] []) @svg-applied)
+            (str "svg-attrs write iff spec for " (:type shape)))
+      (t/is (= (if path? [(:content shape)] []) @path-applied)
+            (str "path write iff spec for " (:type shape)))
+      (t/is (= tail? (boolean (or (seq @svg-applied) (seq @path-applied))))
+            (str "tail fires iff spec for " (:type shape))))))
+
+(t/deftest serialize-shapes-batch-empty-batch-is-noop
+  (let [opts {:include-layout? true :include-fills-strokes? true}
+        flush-calls (atom [])
+        selected (atom [])
+        stubs {:flush (fn [s o] (swap! flush-calls conj {:shapes s :opts o}) nil)
+               :svg-attrs (fn [_] (t/is false "no svg-attrs write on empty batch") nil)
+               :path (fn [_] (t/is false "no path write on empty batch") nil)}
+        result (with-ffi-stubs* stubs
+                 #(serialize-shape/serialize-shapes-batch!
+                   []
+                   opts
+                   (fn [id] (swap! selected conj id))))]
+    (t/is (= [] result) "returns empty prepared")
+    (t/is (empty? @flush-calls) "no flush on empty batch")
+    (t/is (empty? @selected) "no select on empty batch")))
diff --git a/frontend/test/frontend_tests/runner.cljs b/frontend/test/frontend_tests/runner.cljs
index e4b3796282..85c980e34f 100644
--- a/frontend/test/frontend_tests/runner.cljs
+++ b/frontend/test/frontend_tests/runner.cljs
@@ -78,10 +78,12 @@
    [frontend-tests.plugins.value-objects-test]
    [frontend-tests.render-dimensions-test]
    [frontend-tests.render-wasm.process-objects-test]
+   [frontend-tests.render-wasm.serialization-test]
    [frontend-tests.render-wasm.text-editor-apply-styles-test]
    [frontend-tests.render-wasm.text-editor-caret-color-test]
    [frontend-tests.router-test]
    [frontend-tests.svg-fills-test]
+   [frontend-tests.svg-filters-test]
    [frontend-tests.text-editor-paste-guard-test]
    [frontend-tests.tokens.copy-paste-props-test]
    [frontend-tests.tokens.import-export-test]
@@ -205,10 +207,12 @@
    'frontend-tests.plugins.utils-test
    'frontend-tests.plugins.value-objects-test
    'frontend-tests.render-wasm.process-objects-test
+   'frontend-tests.render-wasm.serialization-test
    'frontend-tests.render-wasm.text-editor-apply-styles-test
    'frontend-tests.render-wasm.text-editor-caret-color-test
    'frontend-tests.router-test
    'frontend-tests.svg-fills-test
+   'frontend-tests.svg-filters-test
    'frontend-tests.tokens.copy-paste-props-test
    'frontend-tests.tokens.import-export-test
    'frontend-tests.tokens.logic.token-actions-test
diff --git a/frontend/test/frontend_tests/svg_fills_test.cljs b/frontend/test/frontend_tests/svg_fills_test.cljs
index 1a0d4b66d1..cecb4ad3b8 100644
--- a/frontend/test/frontend_tests/svg_fills_test.cljs
+++ b/frontend/test/frontend_tests/svg_fills_test.cljs
@@ -6,7 +6,7 @@
 
 (ns frontend-tests.svg-fills-test
   (:require
-   [app.render-wasm.svg-fills :as svg-fills]
+   [app.common.render-wasm.svg-derived :as svg-derived]
    [cljs.test :refer [deftest is testing]]))
 
 (def sample-shape
@@ -28,7 +28,7 @@
                                   :style "stop-color:#00ff00;stop-opacity:0"}}]}}})
 
 (deftest builds-gradient-fill-from-svg-defs
-  (let [fills (svg-fills/svg-fill->fills sample-shape)
+  (let [fills (svg-derived/svg-fill->fills sample-shape)
         gradient (get-in (first fills) [:fill-color-gradient])]
     (testing "fallback fill is generated"
       (is (= 1 (count fills))))
@@ -40,7 +40,7 @@
       (is (= 0.5 (:fill-opacity (first fills)))))))
 
 (deftest skips-when-no-svg-fill
-  (is (nil? (svg-fills/svg-fill->fills {:svg-attrs {:fill "none"}}))))
+  (is (nil? (svg-derived/svg-fill->fills {:svg-attrs {:fill "none"}}))))
 
 (def elliptical-shape
   {:selrect {:x 0 :y 0 :width 200 :height 100}
@@ -61,7 +61,7 @@
                                   :style "stop-color:#ffffff;stop-opacity:1"}}]}}})
 
 (deftest builds-elliptical-radial-gradient-with-transform
-  (let [fills (svg-fills/svg-fill->fills elliptical-shape)
+  (let [fills (svg-derived/svg-fill->fills elliptical-shape)
         gradient (get-in (first fills) [:fill-color-gradient])]
     (testing "ellipse from gradientTransform is preserved"
       (is (= 1 (count fills)))
@@ -75,22 +75,22 @@
 
 (deftest resolve-shape-fills-prefers-existing-fills
   (let [fills [{:fill-color "#ff00ff" :fill-opacity 0.75}]
-        resolved (svg-fills/resolve-shape-fills {:fills fills})]
+        resolved (svg-derived/resolve-shape-fills {:fills fills})]
     (is (= fills resolved))))
 
 (deftest resolve-shape-fills-falls-back-to-svg-fill
-  (let [resolved (svg-fills/resolve-shape-fills (assoc sample-shape :fills []))]
-    (is (= (svg-fills/svg-fill->fills sample-shape) resolved))))
+  (let [resolved (svg-derived/resolve-shape-fills (assoc sample-shape :fills []))]
+    (is (= (svg-derived/svg-fill->fills sample-shape) resolved))))
 
 (deftest resolve-shape-fills-defaults-to-black
   (is (= [{:fill-color "#000000" :fill-opacity 1}]
-         (svg-fills/resolve-shape-fills {:type :group
-                                         :svg-attrs {}}))))
+         (svg-derived/resolve-shape-fills {:type :group
+                                           :svg-attrs {}}))))
 
 (deftest resolve-shape-fills-accepts-hex-fill
-  (let [fills (svg-fills/resolve-shape-fills {:fills []
-                                              :type :svg-raw
-                                              :svg-attrs {:fill "#fabada"}})]
+  (let [fills (svg-derived/resolve-shape-fills {:fills []
+                                                :type :svg-raw
+                                                :svg-attrs {:fill "#fabada"}})]
     (is (= 1 (count fills)))
     (is (= "#fabada" (:fill-color (first fills))))))
 
diff --git a/frontend/test/frontend_tests/svg_filters_test.cljs b/frontend/test/frontend_tests/svg_filters_test.cljs
index 80fd1b250a..a8b1fbb90b 100644
--- a/frontend/test/frontend_tests/svg_filters_test.cljs
+++ b/frontend/test/frontend_tests/svg_filters_test.cljs
@@ -6,7 +6,7 @@
 
 (ns frontend-tests.svg-filters-test
   (:require
-   [app.render-wasm.svg-filters :as svg-filters]
+   [app.common.render-wasm.svg-derived :as svg-derived]
    [cljs.test :refer [deftest is testing]]))
 
 (def sample-filter-shape
@@ -17,7 +17,7 @@
                          {:tag :feGaussianBlur :attrs {:stdDeviation "4"}}]}}})
 
 (deftest derives-blur-and-shadow-from-svg-filter
-  (let [shape  (svg-filters/apply-svg-filters sample-filter-shape)
+  (let [shape  (svg-derived/apply-svg-filters sample-filter-shape)
         blur   (:blur shape)
         shadow (:shadow shape)]
     (testing "layer blur derived from feGaussianBlur"
@@ -38,12 +38,12 @@
 (deftest keeps-existing-native-filters
   (let [existing {:blur {:id :existing :type :layer-blur :value 1.0}
                   :shadow [{:id :shadow :style :drop-shadow}]}
-        shape    (svg-filters/apply-svg-filters (merge sample-filter-shape existing))]
+        shape    (svg-derived/apply-svg-filters (merge sample-filter-shape existing))]
     (is (= (:blur existing) (:blur shape)))
     (is (= (:shadow existing) (:shadow shape)))))
 
 (deftest skips-when-no-filter-definition
   (let [shape {:svg-attrs {:fill "#fff"}}
-        result (svg-filters/apply-svg-filters shape)]
+        result (svg-derived/apply-svg-filters shape)]
     (is (= shape result))))