diff --git a/lib/hyperscript/compiler.sx b/lib/hyperscript/compiler.sx
index ec9a784e..f3c227da 100644
--- a/lib/hyperscript/compiler.sx
+++ b/lib/hyperscript/compiler.sx
@@ -7,6 +7,22 @@
 ;;   (hs-to-sx (hs-compile "on click add .active to me"))
 ;;   → (hs-on me "click" (fn (event) (dom-add-class me "active")))
 
+;; ── Compiler plugin registries ────────────────────────────────────
+;; Plugins call (hs-register-command! "head" compile-fn) and
+;; (hs-register-converter! "TypeName" convert-fn) at load time. Both
+;; compile-fn and convert-fn receive a ctx dict (built per call inside
+;; hs-to-sx) exposing :hs-to-sx for recursion plus the AST node fields
+;; the dispatch needs. Compile-fn returns an SX expression.
+(begin
+  (define _hs-command-registry {})
+  (define _hs-converter-registry {})
+  (define
+    hs-register-command!
+    (fn (name compile-fn) (dict-set! _hs-command-registry name compile-fn)))
+  (define
+    hs-register-converter!
+    (fn (name convert-fn) (dict-set! _hs-converter-registry name convert-fn))))
+
 (define
   hs-to-sx
   (let
@@ -952,6 +968,22 @@
           (true
             (let
               ((head (first ast)))
+              (let
+                ((reg-cmd-fn (dict-get _hs-command-registry (str head)))
+                  (reg-conv-fn
+                    (and
+                      (= head (quote as))
+                      (dict-get _hs-converter-registry (nth ast 2)))))
+                (cond
+                  (reg-conv-fn
+                    (reg-conv-fn
+                      {:hs-to-sx hs-to-sx
+                       :ast ast
+                       :value-ast (nth ast 1)
+                       :type-name (nth ast 2)}))
+                  (reg-cmd-fn
+                    (reg-cmd-fn {:hs-to-sx hs-to-sx :ast ast :head head}))
+                  (true
               (cond
                 ((= head (quote __bind-from-detail__))
                   (let
@@ -2667,7 +2699,7 @@
                           (quote begin)
                           (list (quote set!) (quote it) (quote __hs-js))
                           (quote __hs-js))))))
-                (true ast)))))))))
+                (true ast))))))))))))
 
 ;; ── Convenience: source → SX ─────────────────────────────────
 (define
diff --git a/shared/static/wasm/sx/hs-compiler.sx b/shared/static/wasm/sx/hs-compiler.sx
index 07c4d91c..f3c227da 100644
--- a/shared/static/wasm/sx/hs-compiler.sx
+++ b/shared/static/wasm/sx/hs-compiler.sx
@@ -7,6 +7,22 @@
 ;;   (hs-to-sx (hs-compile "on click add .active to me"))
 ;;   → (hs-on me "click" (fn (event) (dom-add-class me "active")))
 
+;; ── Compiler plugin registries ────────────────────────────────────
+;; Plugins call (hs-register-command! "head" compile-fn) and
+;; (hs-register-converter! "TypeName" convert-fn) at load time. Both
+;; compile-fn and convert-fn receive a ctx dict (built per call inside
+;; hs-to-sx) exposing :hs-to-sx for recursion plus the AST node fields
+;; the dispatch needs. Compile-fn returns an SX expression.
+(begin
+  (define _hs-command-registry {})
+  (define _hs-converter-registry {})
+  (define
+    hs-register-command!
+    (fn (name compile-fn) (dict-set! _hs-command-registry name compile-fn)))
+  (define
+    hs-register-converter!
+    (fn (name convert-fn) (dict-set! _hs-converter-registry name convert-fn))))
+
 (define
   hs-to-sx
   (let
@@ -48,6 +64,15 @@
                             prop
                             value))
                         (list (quote hs-query-all) (nth base-ast 1))))
+                    ((and (list? base-ast) (= (first base-ast) (quote query)))
+                      (list
+                        (quote dom-set-prop)
+                        (list
+                          (quote hs-named-target)
+                          (nth base-ast 1)
+                          (list (quote hs-query-first) (nth base-ast 1)))
+                        prop
+                        value))
                     ((and (list? base-ast) (= (first base-ast) dot-sym) (let ((inner (nth base-ast 1))) (and (list? inner) (= (first inner) (quote query)) (let ((s (nth inner 1))) (and (string? s) (> (len s) 0) (= (substring s 0 1) "."))))))
                       (let
                         ((inner (nth base-ast 1))
@@ -221,7 +246,8 @@
                   having-info
                   of-filter-info
                   count-filter-info
-                  elsewhere?)
+                  elsewhere?
+                  or-sources)
                 (cond
                   ((<= (len items) 1)
                     (let
@@ -279,7 +305,27 @@
                                                 having-info
                                                 (get having-info "threshold")
                                                 nil))))
-                                        (true on-call))))))))))))
+                                        (true
+                                          (if
+                                            or-sources
+                                            (cons
+                                              (quote do)
+                                              (cons
+                                                on-call
+                                                (map
+                                                  (fn
+                                                    (pair)
+                                                    (list
+                                                      (quote hs-on)
+                                                      (if
+                                                        (nth pair 1)
+                                                        (hs-to-sx
+                                                          (nth pair 1))
+                                                        (quote me))
+                                                      (first pair)
+                                                      handler))
+                                                  or-sources)))
+                                            on-call)))))))))))))
                   ((= (first items) :from)
                     (scan-on
                       (rest (rest items))
@@ -291,7 +337,8 @@
                       having-info
                       of-filter-info
                       count-filter-info
-                      elsewhere?))
+                      elsewhere?
+                      or-sources))
                   ((= (first items) :filter)
                     (scan-on
                       (rest (rest items))
@@ -303,7 +350,8 @@
                       having-info
                       of-filter-info
                       count-filter-info
-                      elsewhere?))
+                      elsewhere?
+                      or-sources))
                   ((= (first items) :every)
                     (scan-on
                       (rest (rest items))
@@ -315,7 +363,8 @@
                       having-info
                       of-filter-info
                       count-filter-info
-                      elsewhere?))
+                      elsewhere?
+                      or-sources))
                   ((= (first items) :catch)
                     (scan-on
                       (rest (rest items))
@@ -327,7 +376,8 @@
                       having-info
                       of-filter-info
                       count-filter-info
-                      elsewhere?))
+                      elsewhere?
+                      or-sources))
                   ((= (first items) :finally)
                     (scan-on
                       (rest (rest items))
@@ -339,7 +389,8 @@
                       having-info
                       of-filter-info
                       count-filter-info
-                      elsewhere?))
+                      elsewhere?
+                      or-sources))
                   ((= (first items) :having)
                     (scan-on
                       (rest (rest items))
@@ -351,7 +402,8 @@
                       (nth items 1)
                       of-filter-info
                       count-filter-info
-                      elsewhere?))
+                      elsewhere?
+                      or-sources))
                   ((= (first items) :of-filter)
                     (scan-on
                       (rest (rest items))
@@ -363,7 +415,8 @@
                       having-info
                       (nth items 1)
                       count-filter-info
-                      elsewhere?))
+                      elsewhere?
+                      or-sources))
                   ((= (first items) :count-filter)
                     (scan-on
                       (rest (rest items))
@@ -375,7 +428,8 @@
                       having-info
                       of-filter-info
                       (nth items 1)
-                      elsewhere?))
+                      elsewhere?
+                      or-sources))
                   ((= (first items) :elsewhere)
                     (scan-on
                       (rest (rest items))
@@ -387,6 +441,20 @@
                       having-info
                       of-filter-info
                       count-filter-info
+                      (nth items 1)
+                      or-sources))
+                  ((= (first items) :or-sources)
+                    (scan-on
+                      (rest (rest items))
+                      source
+                      filter
+                      every?
+                      catch-info
+                      finally-info
+                      having-info
+                      of-filter-info
+                      count-filter-info
+                      elsewhere?
                       (nth items 1)))
                   (true
                     (scan-on
@@ -399,8 +467,9 @@
                       having-info
                       of-filter-info
                       count-filter-info
-                      elsewhere?)))))
-            (scan-on (rest parts) nil nil false nil nil nil nil nil false)))))
+                      elsewhere?
+                      or-sources)))))
+            (scan-on (rest parts) nil nil false nil nil nil nil nil false nil)))))
     (define
       emit-send
       (fn
@@ -899,6 +968,22 @@
           (true
             (let
               ((head (first ast)))
+              (let
+                ((reg-cmd-fn (dict-get _hs-command-registry (str head)))
+                  (reg-conv-fn
+                    (and
+                      (= head (quote as))
+                      (dict-get _hs-converter-registry (nth ast 2)))))
+                (cond
+                  (reg-conv-fn
+                    (reg-conv-fn
+                      {:hs-to-sx hs-to-sx
+                       :ast ast
+                       :value-ast (nth ast 1)
+                       :type-name (nth ast 2)}))
+                  (reg-cmd-fn
+                    (reg-cmd-fn {:hs-to-sx hs-to-sx :ast ast :head head}))
+                  (true
               (cond
                 ((= head (quote __bind-from-detail__))
                   (let
@@ -2614,7 +2699,7 @@
                           (quote begin)
                           (list (quote set!) (quote it) (quote __hs-js))
                           (quote __hs-js))))))
-                (true ast)))))))))
+                (true ast))))))))))))
 
 ;; ── Convenience: source → SX ─────────────────────────────────
 (define