diff --git a/shared/static/scripts/sx-browser.js b/shared/static/scripts/sx-browser.js
index 34416bf..dd29465 100644
--- a/shared/static/scripts/sx-browser.js
+++ b/shared/static/scripts/sx-browser.js
@@ -14,7 +14,7 @@
   // =========================================================================
 
   var NIL = Object.freeze({ _nil: true, toString: function() { return "nil"; } });
-  var SX_VERSION = "2026-03-13T19:15:06Z";
+  var SX_VERSION = "2026-03-13T22:49:51Z";
 
   function isNil(x) { return x === NIL || x === null || x === undefined; }
   function isSxTruthy(x) { return x !== false && !isNil(x); }
@@ -61,13 +61,6 @@
   }
   SxSignal.prototype._signal = true;
 
-  function TrackingCtx(notifyFn) {
-    this.notifyFn = notifyFn;
-    this.deps = [];
-  }
-
-  var _trackingContext = null;
-
   function Macro(params, restParam, body, closure, name) {
     this.params = params;
     this.restParam = restParam;
@@ -243,12 +236,6 @@
   function signalRemoveSub(s, fn) { var i = s.subscribers.indexOf(fn); if (i >= 0) s.subscribers.splice(i, 1); }
   function signalDeps(s) { return s.deps.slice(); }
   function signalSetDeps(s, deps) { s.deps = Array.isArray(deps) ? deps.slice() : []; }
-  function setTrackingContext(ctx) { _trackingContext = ctx; }
-  function getTrackingContext() { return _trackingContext || NIL; }
-  function makeTrackingContext(notifyFn) { return new TrackingCtx(notifyFn); }
-  function trackingContextDeps(ctx) { return ctx ? ctx.deps : []; }
-  function trackingContextAddDep(ctx, s) { if (ctx && ctx.deps.indexOf(s) < 0) ctx.deps.push(s); }
-  function trackingContextNotifyFn(ctx) { return ctx ? ctx.notifyFn : NIL; }
 
   // invoke — call any callable (native fn or SX lambda) with args.
   // Transpiled code emits direct calls f(args) which fail on SX lambdas
@@ -1208,14 +1195,7 @@ return append_b(inits, nth(binding, 1)); }, bindings) : reduce(function(acc, pai
   var before = trampoline(evalExpr(first(args), env));
   var body = trampoline(evalExpr(nth(args, 1), env));
   var after = trampoline(evalExpr(nth(args, 2), env));
-  callThunk(before, env);
-  pushWind(before, after);
-  return (function() {
-  var result = callThunk(body, env);
-  popWind();
-  callThunk(after, env);
-  return result;
-})();
+  return dynamicWindCall(before, body, after, env);
 })(); };
 
   // sf-scope
@@ -1936,7 +1916,7 @@ return result; }, args);
 
   // render-to-dom
   var renderToDom = function(expr, env, ns) { setRenderActiveB(true);
-return (function() { var _m = typeOf(expr); if (_m == "nil") return createFragment(); if (_m == "boolean") return createFragment(); if (_m == "raw-html") return domParseHtml(rawHtmlContent(expr)); if (_m == "string") return createTextNode(expr); if (_m == "number") return createTextNode((String(expr))); if (_m == "symbol") return renderToDom(trampoline(evalExpr(expr, env)), env, ns); if (_m == "keyword") return createTextNode(keywordName(expr)); if (_m == "dom-node") return expr; if (_m == "spread") return (sxEmit("element-attrs", spreadAttrs(expr)), expr); if (_m == "dict") return createFragment(); if (_m == "list") return (isSxTruthy(isEmpty(expr)) ? createFragment() : renderDomList(expr, env, ns)); return (isSxTruthy(isSignal(expr)) ? (isSxTruthy(_islandScope) ? reactiveText(expr) : createTextNode((String(deref(expr))))) : createTextNode((String(expr)))); })(); };
+return (function() { var _m = typeOf(expr); if (_m == "nil") return createFragment(); if (_m == "boolean") return createFragment(); if (_m == "raw-html") return domParseHtml(rawHtmlContent(expr)); if (_m == "string") return createTextNode(expr); if (_m == "number") return createTextNode((String(expr))); if (_m == "symbol") return renderToDom(trampoline(evalExpr(expr, env)), env, ns); if (_m == "keyword") return createTextNode(keywordName(expr)); if (_m == "dom-node") return expr; if (_m == "spread") return (sxEmit("element-attrs", spreadAttrs(expr)), expr); if (_m == "dict") return createFragment(); if (_m == "list") return (isSxTruthy(isEmpty(expr)) ? createFragment() : renderDomList(expr, env, ns)); return (isSxTruthy(isSignal(expr)) ? (isSxTruthy(sxContext("sx-island-scope", NIL)) ? reactiveText(expr) : createTextNode((String(deref(expr))))) : createTextNode((String(expr)))); })(); };
 
   // render-dom-list
   var renderDomList = function(expr, env, ns) { return (function() {
@@ -1947,7 +1927,7 @@ return (function() { var _m = typeOf(expr); if (_m == "nil") return createFragme
   return (isSxTruthy((name == "raw!")) ? renderDomRaw(args, env) : (isSxTruthy((name == "<>")) ? renderDomFragment(args, env, ns) : (isSxTruthy((name == "lake")) ? renderDomLake(args, env, ns) : (isSxTruthy((name == "marsh")) ? renderDomMarsh(args, env, ns) : (isSxTruthy(startsWith(name, "html:")) ? renderDomElement(slice(name, 5), args, env, ns) : (isSxTruthy(isRenderDomForm(name)) ? (isSxTruthy((isSxTruthy(contains(HTML_TAGS, name)) && sxOr((isSxTruthy((len(args) > 0)) && (typeOf(first(args)) == "keyword")), ns))) ? renderDomElement(name, args, env, ns) : dispatchRenderForm(name, expr, env, ns)) : (isSxTruthy((isSxTruthy(envHas(env, name)) && isMacro(envGet(env, name)))) ? renderToDom(expandMacro(envGet(env, name), args, env), env, ns) : (isSxTruthy(contains(HTML_TAGS, name)) ? renderDomElement(name, args, env, ns) : (isSxTruthy((isSxTruthy(startsWith(name, "~")) && isSxTruthy(envHas(env, name)) && isIsland(envGet(env, name)))) ? renderDomIsland(envGet(env, name), args, env, ns) : (isSxTruthy(startsWith(name, "~")) ? (function() {
   var comp = envGet(env, name);
   return (isSxTruthy(isComponent(comp)) ? renderDomComponent(comp, args, env, ns) : renderDomUnknownComponent(name));
-})() : (isSxTruthy((isSxTruthy((indexOf_(name, "-") > 0)) && isSxTruthy((len(args) > 0)) && (typeOf(first(args)) == "keyword"))) ? renderDomElement(name, args, env, ns) : (isSxTruthy(ns) ? renderDomElement(name, args, env, ns) : (isSxTruthy((isSxTruthy((name == "deref")) && _islandScope)) ? (function() {
+})() : (isSxTruthy((isSxTruthy((indexOf_(name, "-") > 0)) && isSxTruthy((len(args) > 0)) && (typeOf(first(args)) == "keyword"))) ? renderDomElement(name, args, env, ns) : (isSxTruthy(ns) ? renderDomElement(name, args, env, ns) : (isSxTruthy((isSxTruthy((name == "deref")) && sxContext("sx-island-scope", NIL))) ? (function() {
   var sigOrVal = trampoline(evalExpr(first(args), env));
   return (isSxTruthy(isSignal(sigOrVal)) ? reactiveText(sigOrVal) : createTextNode((String(deref(sigOrVal)))));
 })() : renderToDom(trampoline(evalExpr(expr, env)), env, ns))))))))))))));
@@ -1983,14 +1963,14 @@ return (function() { var _m = typeOf(expr); if (_m == "nil") return createFragme
 })() : (isSxTruthy((attrName == "key")) ? (function() {
   var attrVal = trampoline(evalExpr(attrExpr, env));
   return domSetAttr(el, "key", (String(attrVal)));
-})() : (isSxTruthy(_islandScope) ? reactiveAttr(el, attrName, function() { return trampoline(evalExpr(attrExpr, env)); }) : (function() {
+})() : (isSxTruthy(sxContext("sx-island-scope", NIL)) ? reactiveAttr(el, attrName, function() { return trampoline(evalExpr(attrExpr, env)); }) : (function() {
   var attrVal = trampoline(evalExpr(attrExpr, env));
   return (isSxTruthy(sxOr(isNil(attrVal), (attrVal == false))) ? NIL : (isSxTruthy(contains(BOOLEAN_ATTRS, attrName)) ? (isSxTruthy(attrVal) ? domSetAttr(el, attrName, "") : NIL) : (isSxTruthy((attrVal == true)) ? domSetAttr(el, attrName, "") : domSetAttr(el, attrName, (String(attrVal))))));
 })())))));
   return assoc(state, "skip", true, "i", (get(state, "i") + 1));
 })() : ((isSxTruthy(!isSxTruthy(contains(VOID_ELEMENTS, tag))) ? (function() {
   var child = renderToDom(arg, env, newNs);
-  return (isSxTruthy((isSxTruthy(isSpread(child)) && _islandScope)) ? reactiveSpread(el, function() { return renderToDom(arg, env, newNs); }) : (isSxTruthy(isSpread(child)) ? NIL : domAppend(el, child)));
+  return (isSxTruthy((isSxTruthy(isSpread(child)) && sxContext("sx-island-scope", NIL))) ? reactiveSpread(el, function() { return renderToDom(arg, env, newNs); }) : (isSxTruthy(isSpread(child)) ? NIL : domAppend(el, child)));
 })() : NIL), assoc(state, "i", (get(state, "i") + 1)))));
 })(); }, {["i"]: 0, ["skip"]: false}, args);
   { var _c = sxEmitted("element-attrs"); for (var _i = 0; _i < _c.length; _i++) { var spreadDict = _c[_i]; { var _c = keys(spreadDict); for (var _i = 0; _i < _c.length; _i++) { var key = _c[_i]; (function() {
@@ -2066,7 +2046,7 @@ return (function() { var _m = typeOf(expr); if (_m == "nil") return createFragme
   var isRenderDomForm = function(name) { return contains(RENDER_DOM_FORMS, name); };
 
   // dispatch-render-form
-  var dispatchRenderForm = function(name, expr, env, ns) { return (isSxTruthy((name == "if")) ? (isSxTruthy(_islandScope) ? (function() {
+  var dispatchRenderForm = function(name, expr, env, ns) { return (isSxTruthy((name == "if")) ? (isSxTruthy(sxContext("sx-island-scope", NIL)) ? (function() {
   var marker = createComment("r-if");
   var currentNodes = [];
   var initialResult = NIL;
@@ -2089,7 +2069,7 @@ return (function() { var _m = typeOf(expr); if (_m == "nil") return createFragme
 })() : (function() {
   var condVal = trampoline(evalExpr(nth(expr, 1), env));
   return (isSxTruthy(condVal) ? renderToDom(nth(expr, 2), env, ns) : (isSxTruthy((len(expr) > 3)) ? renderToDom(nth(expr, 3), env, ns) : createFragment()));
-})()) : (isSxTruthy((name == "when")) ? (isSxTruthy(_islandScope) ? (function() {
+})()) : (isSxTruthy((name == "when")) ? (isSxTruthy(sxContext("sx-island-scope", NIL)) ? (function() {
   var marker = createComment("r-when");
   var currentNodes = [];
   var initialResult = NIL;
@@ -2116,7 +2096,7 @@ return (function() { var _m = typeOf(expr); if (_m == "nil") return createFragme
   var frag = createFragment();
   { var _c = range(2, len(expr)); for (var _i = 0; _i < _c.length; _i++) { var i = _c[_i]; domAppend(frag, renderToDom(nth(expr, i), env, ns)); } }
   return frag;
-})())) : (isSxTruthy((name == "cond")) ? (isSxTruthy(_islandScope) ? (function() {
+})())) : (isSxTruthy((name == "cond")) ? (isSxTruthy(sxContext("sx-island-scope", NIL)) ? (function() {
   var marker = createComment("r-cond");
   var currentNodes = [];
   var initialResult = NIL;
@@ -2162,7 +2142,7 @@ return (function() { var _m = typeOf(expr); if (_m == "nil") return createFragme
   return frag;
 })()) : (isSxTruthy(isDefinitionForm(name)) ? (trampoline(evalExpr(expr, env)), createFragment()) : (isSxTruthy((name == "map")) ? (function() {
   var collExpr = nth(expr, 2);
-  return (isSxTruthy((isSxTruthy(_islandScope) && isSxTruthy((typeOf(collExpr) == "list")) && isSxTruthy((len(collExpr) > 1)) && isSxTruthy((typeOf(first(collExpr)) == "symbol")) && (symbolName(first(collExpr)) == "deref"))) ? (function() {
+  return (isSxTruthy((isSxTruthy(sxContext("sx-island-scope", NIL)) && isSxTruthy((typeOf(collExpr) == "list")) && isSxTruthy((len(collExpr) > 1)) && isSxTruthy((typeOf(first(collExpr)) == "symbol")) && (symbolName(first(collExpr)) == "deref"))) ? (function() {
   var f = trampoline(evalExpr(nth(expr, 1), env));
   var sig = trampoline(evalExpr(nth(collExpr, 1), env));
   return (isSxTruthy(isSignal(sig)) ? reactiveList(f, sig, env, ns) : (function() {
@@ -2490,15 +2470,13 @@ return (isSxTruthy(testFn()) ? (function() {
   domSetAttr(container, "data-sx-boundary", "true");
   effect(function() { deref(retryVersion);
 domSetProp(container, "innerHTML", "");
-return (function() {
-  var savedScope = _islandScope;
-  _islandScope = NIL;
-  return tryCatch(function() { (function() {
+scopePush("sx-island-scope", NIL);
+return tryCatch(function() { (function() {
   var frag = createFragment();
   { var _c = bodyExprs; for (var _i = 0; _i < _c.length; _i++) { var child = _c[_i]; domAppend(frag, renderToDom(child, env, ns)); } }
   return domAppend(container, frag);
 })();
-return (_islandScope = savedScope); }, function(err) { _islandScope = savedScope;
+return scopePop("sx-island-scope"); }, function(err) { scopePop("sx-island-scope");
 return (function() {
   var fallbackFn = trampoline(evalExpr(fallbackExpr, env));
   var retryFn = function() { return swap_b(retryVersion, function(n) { return (n + 1); }); };
@@ -2506,8 +2484,7 @@ return (function() {
   var fallbackDom = (isSxTruthy(isLambda(fallbackFn)) ? renderLambdaDom(fallbackFn, [err, retryFn], env, ns) : renderToDom(apply(fallbackFn, [err, retryFn]), env, ns));
   return domAppend(container, fallbackDom);
 })();
-})(); });
-})(); });
+})(); }); });
   return container;
 })(); };
 
@@ -4272,10 +4249,13 @@ callExpr.push(dictGet(kwargs, k)); } }
 
   // deref
   var deref = function(s) { return (isSxTruthy(!isSxTruthy(isSignal(s))) ? s : (function() {
-  var ctx = getTrackingContext();
+  var ctx = sxContext("sx-reactive", NIL);
   if (isSxTruthy(ctx)) {
-  trackingContextAddDep(ctx, s);
-  signalAddSub(s, trackingContextNotifyFn(ctx));
+  (function() {
+  var depList = get(ctx, "deps");
+  var notifyFn = get(ctx, "notify");
+  return (isSxTruthy(!isSxTruthy(contains(depList, s))) ? (append_b(depList, s), signalAddSub(s, notifyFn)) : NIL);
+})();
 }
   return signalValue(s);
 })()); };
@@ -4302,21 +4282,18 @@ callExpr.push(dictGet(kwargs, k)); } }
   var recompute = function() { { var _c = signalDeps(s); for (var _i = 0; _i < _c.length; _i++) { var dep = _c[_i]; signalRemoveSub(dep, recompute); } }
 signalSetDeps(s, []);
 return (function() {
-  var ctx = makeTrackingContext(recompute);
-  return (function() {
-  var prev = getTrackingContext();
-  setTrackingContext(ctx);
+  var ctx = {["deps"]: [], ["notify"]: recompute};
+  scopePush("sx-reactive", ctx);
   return (function() {
   var newVal = invoke(computeFn);
-  setTrackingContext(prev);
-  signalSetDeps(s, trackingContextDeps(ctx));
+  scopePop("sx-reactive");
+  signalSetDeps(s, get(ctx, "deps"));
   return (function() {
   var old = signalValue(s);
   signalSetValue(s, newVal);
   return (isSxTruthy(!isSxTruthy(isIdentical(old, newVal))) ? notifySubscribers(s) : NIL);
 })();
 })();
-})();
 })(); };
   recompute();
   registerInScope(function() { return disposeComputed(s); });
@@ -4331,17 +4308,14 @@ return (function() {
   var cleanupFn = NIL;
   return (function() {
   var runEffect = function() { return (isSxTruthy(!isSxTruthy(disposed)) ? ((isSxTruthy(cleanupFn) ? invoke(cleanupFn) : NIL), forEach(function(dep) { return signalRemoveSub(dep, runEffect); }, deps), (deps = []), (function() {
-  var ctx = makeTrackingContext(runEffect);
-  return (function() {
-  var prev = getTrackingContext();
-  setTrackingContext(ctx);
+  var ctx = {["deps"]: [], ["notify"]: runEffect};
+  scopePush("sx-reactive", ctx);
   return (function() {
   var result = invoke(effectFn);
-  setTrackingContext(prev);
-  deps = trackingContextDeps(ctx);
+  scopePop("sx-reactive");
+  deps = get(ctx, "deps");
   return (isSxTruthy(isCallable(result)) ? (cleanupFn = result) : NIL);
 })();
-})();
 })()) : NIL); };
   runEffect();
   return (function() {
@@ -4390,22 +4364,19 @@ return (isSxTruthy((_batchDepth == 0)) ? (function() {
   // dispose-computed
   var disposeComputed = function(s) { return (isSxTruthy(isSignal(s)) ? (forEach(function(dep) { return signalRemoveSub(dep, NIL); }, signalDeps(s)), signalSetDeps(s, [])) : NIL); };
 
-  // *island-scope*
-  var _islandScope = NIL;
-
   // with-island-scope
-  var withIslandScope = function(scopeFn, bodyFn) { return (function() {
-  var prev = _islandScope;
-  _islandScope = scopeFn;
-  return (function() {
+  var withIslandScope = function(scopeFn, bodyFn) { scopePush("sx-island-scope", scopeFn);
+return (function() {
   var result = bodyFn();
-  _islandScope = prev;
+  scopePop("sx-island-scope");
   return result;
-})();
 })(); };
 
   // register-in-scope
-  var registerInScope = function(disposable) { return (isSxTruthy(_islandScope) ? _islandScope(disposable) : NIL); };
+  var registerInScope = function(disposable) { return (function() {
+  var collector = sxContext("sx-island-scope", NIL);
+  return (isSxTruthy(collector) ? invoke(collector, disposable) : NIL);
+})(); };
 
   // with-marsh-scope
   var withMarshScope = function(marshEl, bodyFn) { return (function() {
diff --git a/shared/sx/ref/adapter-dom.sx b/shared/sx/ref/adapter-dom.sx
index 323b23e..18a40fb 100644
--- a/shared/sx/ref/adapter-dom.sx
+++ b/shared/sx/ref/adapter-dom.sx
@@ -59,7 +59,7 @@
       ;; Signal → reactive text in island scope, deref outside
       :else
         (if (signal? expr)
-          (if *island-scope*
+          (if (context "sx-island-scope" nil)
             (reactive-text expr)
             (create-text-node (str (deref expr))))
           (create-text-node (str expr))))))
@@ -143,7 +143,7 @@
                 (render-dom-element name args env ns)
 
               ;; deref in island scope → reactive text node
-              (and (= name "deref") *island-scope*)
+              (and (= name "deref") (context "sx-island-scope" nil))
                 (let ((sig-or-val (trampoline (eval-expr (first args) env))))
                   (if (signal? sig-or-val)
                     (reactive-text sig-or-val)
@@ -215,7 +215,7 @@
                     ;; Inside island scope: reactive attribute binding.
                     ;; The effect tracks signal deps automatically — if none
                     ;; are deref'd, it fires once and never again (safe).
-                    *island-scope*
+                    (context "sx-island-scope" nil)
                       (reactive-attr el attr-name
                         (fn () (trampoline (eval-expr attr-expr env))))
                     ;; Static attribute (outside islands)
@@ -237,7 +237,7 @@
                     (let ((child (render-to-dom arg env new-ns)))
                       (cond
                         ;; Reactive spread: track signal deps, update attrs on change
-                        (and (spread? child) *island-scope*)
+                        (and (spread? child) (context "sx-island-scope" nil))
                           (reactive-spread el (fn () (render-to-dom arg env new-ns)))
                         ;; Static spread: already emitted via provide, skip
                         (spread? child) nil
@@ -392,7 +392,7 @@
     (cond
       ;; if — reactive inside islands (re-renders when signal deps change)
       (= name "if")
-        (if *island-scope*
+        (if (context "sx-island-scope" nil)
           (let ((marker (create-comment "r-if"))
                 (current-nodes (list))
                 (initial-result nil))
@@ -440,7 +440,7 @@
 
       ;; when — reactive inside islands
       (= name "when")
-        (if *island-scope*
+        (if (context "sx-island-scope" nil)
           (let ((marker (create-comment "r-when"))
                 (current-nodes (list))
                 (initial-result nil))
@@ -486,7 +486,7 @@
 
       ;; cond — reactive inside islands
       (= name "cond")
-        (if *island-scope*
+        (if (context "sx-island-scope" nil)
           (let ((marker (create-comment "r-cond"))
                 (current-nodes (list))
                 (initial-result nil))
@@ -563,7 +563,7 @@
       ;; map — reactive-list when mapping over a signal inside an island
       (= name "map")
         (let ((coll-expr (nth expr 2)))
-          (if (and *island-scope*
+          (if (and (context "sx-island-scope" nil)
                    (= (type-of coll-expr) "list")
                    (> (len coll-expr) 1)
                    (= (type-of (first coll-expr)) "symbol")
@@ -1168,7 +1168,7 @@
       (dom-set-attr container "data-sx-boundary" "true")
 
       ;; The entire body is rendered inside ONE effect + try-catch.
-      ;; Body renders WITHOUT *island-scope* so that if/when/cond use static
+      ;; Body renders WITHOUT island scope so that if/when/cond use static
       ;; paths — their signal reads become direct deref calls tracked by THIS
       ;; effect. Errors from signal changes throw synchronously within try-catch.
       ;; The error boundary's own effect handles all reactivity for its subtree.
@@ -1179,31 +1179,30 @@
         ;; Clear container
         (dom-set-prop container "innerHTML" "")
 
-        ;; Save and clear island scope BEFORE try-catch so it can be
-        ;; restored in both success and error paths.
-        (let ((saved-scope *island-scope*))
-          (set! *island-scope* nil)
-          (try-catch
-            (fn ()
-              ;; Body renders statically — signal reads tracked by THIS effect,
-              ;; throws propagate to our try-catch.
-              (let ((frag (create-fragment)))
-                (for-each
-                  (fn (child)
-                    (dom-append frag (render-to-dom child env ns)))
-                  body-exprs)
-                (dom-append container frag))
-              (set! *island-scope* saved-scope))
-            (fn (err)
-              ;; Restore scope first, then render fallback
-              (set! *island-scope* saved-scope)
+        ;; Push nil island scope to suppress reactive rendering in body.
+        ;; Pop in both success and error paths.
+        (scope-push! "sx-island-scope" nil)
+        (try-catch
+          (fn ()
+            ;; Body renders statically — signal reads tracked by THIS effect,
+            ;; throws propagate to our try-catch.
+            (let ((frag (create-fragment)))
+              (for-each
+                (fn (child)
+                  (dom-append frag (render-to-dom child env ns)))
+                body-exprs)
+              (dom-append container frag))
+            (scope-pop! "sx-island-scope"))
+          (fn (err)
+            ;; Pop scope first, then render fallback
+            (scope-pop! "sx-island-scope")
               (let ((fallback-fn (trampoline (eval-expr fallback-expr env)))
                     (retry-fn (fn () (swap! retry-version (fn (n) (+ n 1))))))
                 (let ((fallback-dom
                         (if (lambda? fallback-fn)
                           (render-lambda-dom fallback-fn (list err retry-fn) env ns)
                           (render-to-dom (apply fallback-fn (list err retry-fn)) env ns))))
-                  (dom-append container fallback-dom))))))))
+                  (dom-append container fallback-dom)))))))
 
       container)))
 
diff --git a/shared/sx/ref/bootstrap_py.py b/shared/sx/ref/bootstrap_py.py
index 57f3725..56fc1ca 100644
--- a/shared/sx/ref/bootstrap_py.py
+++ b/shared/sx/ref/bootstrap_py.py
@@ -165,12 +165,6 @@ class PyEmitter:
             "signal-remove-sub!": "signal_remove_sub",
             "signal-deps": "signal_deps",
             "signal-set-deps!": "signal_set_deps",
-            "set-tracking-context!": "set_tracking_context",
-            "get-tracking-context": "get_tracking_context",
-            "make-tracking-context": "make_tracking_context",
-            "tracking-context-deps": "tracking_context_deps",
-            "tracking-context-add-dep!": "tracking_context_add_dep",
-            "tracking-context-notify-fn": "tracking_context_notify_fn",
             "identical?": "is_identical",
             "notify-subscribers": "notify_subscribers",
             "flush-subscribers": "flush_subscribers",
@@ -179,7 +173,6 @@ class PyEmitter:
             "register-in-scope": "register_in_scope",
             "*batch-depth*": "_batch_depth",
             "*batch-queue*": "_batch_queue",
-            "*island-scope*": "_island_scope",
             "*store-registry*": "_store_registry",
             "def-store": "def_store",
             "use-store": "use_store",
diff --git a/shared/sx/ref/js.sx b/shared/sx/ref/js.sx
index 9bd79d4..743817a 100644
--- a/shared/sx/ref/js.sx
+++ b/shared/sx/ref/js.sx
@@ -87,12 +87,6 @@
   "signal-remove-sub!" "signalRemoveSub"
   "signal-deps" "signalDeps"
   "signal-set-deps!" "signalSetDeps"
-  "set-tracking-context!" "setTrackingContext"
-  "get-tracking-context" "getTrackingContext"
-  "make-tracking-context" "makeTrackingContext"
-  "tracking-context-deps" "trackingContextDeps"
-  "tracking-context-add-dep!" "trackingContextAddDep"
-  "tracking-context-notify-fn" "trackingContextNotifyFn"
   "identical?" "isIdentical"
   "notify-subscribers" "notifySubscribers"
   "flush-subscribers" "flushSubscribers"
@@ -101,7 +95,6 @@
   "register-in-scope" "registerInScope"
   "*batch-depth*" "_batchDepth"
   "*batch-queue*" "_batchQueue"
-  "*island-scope*" "_islandScope"
   "*store-registry*" "_storeRegistry"
   "def-store" "defStore"
   "use-store" "useStore"
diff --git a/shared/sx/ref/platform_js.py b/shared/sx/ref/platform_js.py
index 69ea298..75d5533 100644
--- a/shared/sx/ref/platform_js.py
+++ b/shared/sx/ref/platform_js.py
@@ -858,13 +858,6 @@ PREAMBLE = '''\
   }
   SxSignal.prototype._signal = true;
 
-  function TrackingCtx(notifyFn) {
-    this.notifyFn = notifyFn;
-    this.deps = [];
-  }
-
-  var _trackingContext = null;
-
   function Macro(params, restParam, body, closure, name) {
     this.params = params;
     this.restParam = restParam;
@@ -1269,12 +1262,6 @@ PLATFORM_JS_PRE = '''
   function signalRemoveSub(s, fn) { var i = s.subscribers.indexOf(fn); if (i >= 0) s.subscribers.splice(i, 1); }
   function signalDeps(s) { return s.deps.slice(); }
   function signalSetDeps(s, deps) { s.deps = Array.isArray(deps) ? deps.slice() : []; }
-  function setTrackingContext(ctx) { _trackingContext = ctx; }
-  function getTrackingContext() { return _trackingContext || NIL; }
-  function makeTrackingContext(notifyFn) { return new TrackingCtx(notifyFn); }
-  function trackingContextDeps(ctx) { return ctx ? ctx.deps : []; }
-  function trackingContextAddDep(ctx, s) { if (ctx && ctx.deps.indexOf(s) < 0) ctx.deps.push(s); }
-  function trackingContextNotifyFn(ctx) { return ctx ? ctx.notifyFn : NIL; }
 
   // invoke — call any callable (native fn or SX lambda) with args.
   // Transpiled code emits direct calls f(args) which fail on SX lambdas
diff --git a/shared/sx/ref/platform_py.py b/shared/sx/ref/platform_py.py
index be63bd4..d3ef8e7 100644
--- a/shared/sx/ref/platform_py.py
+++ b/shared/sx/ref/platform_py.py
@@ -481,17 +481,6 @@ class _Signal:
         self.deps = []
 
 
-class _TrackingContext:
-    """Context for discovering signal dependencies."""
-    __slots__ = ("notify_fn", "deps")
-    def __init__(self, notify_fn):
-        self.notify_fn = notify_fn
-        self.deps = []
-
-
-_tracking_context = None
-
-
 def make_signal(value):
     return _Signal(value)
 
@@ -532,33 +521,6 @@ def signal_set_deps(s, deps):
         s.deps = list(deps) if isinstance(deps, list) else []
 
 
-def set_tracking_context(ctx):
-    global _tracking_context
-    _tracking_context = ctx
-
-
-def get_tracking_context():
-    global _tracking_context
-    return _tracking_context if _tracking_context is not None else NIL
-
-
-def make_tracking_context(notify_fn):
-    return _TrackingContext(notify_fn)
-
-
-def tracking_context_deps(ctx):
-    return ctx.deps if isinstance(ctx, _TrackingContext) else []
-
-
-def tracking_context_add_dep(ctx, s):
-    if isinstance(ctx, _TrackingContext) and s not in ctx.deps:
-        ctx.deps.append(s)
-
-
-def tracking_context_notify_fn(ctx):
-    return ctx.notify_fn if isinstance(ctx, _TrackingContext) else NIL
-
-
 def invoke(f, *args):
     """Call f with args — handles both native callables and SX lambdas.
 
diff --git a/shared/sx/ref/py.sx b/shared/sx/ref/py.sx
index 8582428..3a66658 100644
--- a/shared/sx/ref/py.sx
+++ b/shared/sx/ref/py.sx
@@ -84,12 +84,6 @@
   "signal-remove-sub!" "signal_remove_sub"
   "signal-deps" "signal_deps"
   "signal-set-deps!" "signal_set_deps"
-  "set-tracking-context!" "set_tracking_context"
-  "get-tracking-context" "get_tracking_context"
-  "make-tracking-context" "make_tracking_context"
-  "tracking-context-deps" "tracking_context_deps"
-  "tracking-context-add-dep!" "tracking_context_add_dep"
-  "tracking-context-notify-fn" "tracking_context_notify_fn"
   "identical?" "is_identical"
   "notify-subscribers" "notify_subscribers"
   "flush-subscribers" "flush_subscribers"
@@ -98,7 +92,6 @@
   "register-in-scope" "register_in_scope"
   "*batch-depth*" "_batch_depth"
   "*batch-queue*" "_batch_queue"
-  "*island-scope*" "_island_scope"
   "*store-registry*" "_store_registry"
   "def-store" "def_store"
   "use-store" "use_store"
diff --git a/shared/sx/ref/run_signal_tests.py b/shared/sx/ref/run_signal_tests.py
new file mode 100644
index 0000000..5332096
--- /dev/null
+++ b/shared/sx/ref/run_signal_tests.py
@@ -0,0 +1,160 @@
+#!/usr/bin/env python3
+"""Run test-signals.sx using the bootstrapped evaluator with signal primitives.
+
+Uses bootstrapped signal functions from sx_ref.py directly, patching invoke
+to handle SX lambdas from the interpreter (test expressions create lambdas
+that need evaluator dispatch).
+"""
+from __future__ import annotations
+import os, sys
+
+_HERE = os.path.dirname(os.path.abspath(__file__))
+_PROJECT = os.path.abspath(os.path.join(_HERE, "..", "..", ".."))
+sys.path.insert(0, _PROJECT)
+
+from shared.sx.parser import parse_all
+from shared.sx.ref import sx_ref
+from shared.sx.ref.sx_ref import eval_expr, trampoline, make_env, scope_push, scope_pop, sx_context
+from shared.sx.types import NIL, Island, Lambda
+
+# Build env with primitives
+env = make_env()
+
+# --- Patch invoke and apply BEFORE anything else ---
+# Test expressions create SX Lambdas that bootstrapped code calls via invoke/apply.
+# Patch the module-level functions so all bootstrapped functions see them.
+def _invoke(f, *args):
+    if isinstance(f, Lambda):
+        return trampoline(eval_expr([f] + list(args), env))
+    return f(*args)
+sx_ref.__dict__["invoke"] = _invoke
+
+# apply is used by swap! and other forms to call functions with arg lists
+def _apply(f, args):
+    if isinstance(f, Lambda):
+        return trampoline(eval_expr([f] + list(args), env))
+    return f(*args)
+sx_ref.__dict__["apply"] = _apply
+
+# cons needs to handle tuples from Python *args (swap! passes &rest as tuple)
+_orig_cons = sx_ref.PRIMITIVES.get("cons")
+def _cons(x, c):
+    if isinstance(c, tuple):
+        c = list(c)
+    return [x] + (c or [])
+sx_ref.__dict__["cons"] = _cons
+sx_ref.PRIMITIVES["cons"] = _cons
+
+# Platform test functions
+_suite_stack: list[str] = []
+_pass_count = 0
+_fail_count = 0
+
+def _try_call(thunk):
+    try:
+        trampoline(eval_expr([thunk], env))
+        return {"ok": True}
+    except Exception as e:
+        return {"ok": False, "error": str(e)}
+
+def _report_pass(name):
+    global _pass_count
+    _pass_count += 1
+    ctx = " > ".join(_suite_stack)
+    print(f"  PASS: {ctx} > {name}")
+    return NIL
+
+def _report_fail(name, error):
+    global _fail_count
+    _fail_count += 1
+    ctx = " > ".join(_suite_stack)
+    print(f"  FAIL: {ctx} > {name}: {error}")
+    return NIL
+
+def _push_suite(name):
+    _suite_stack.append(name)
+    print(f"{'  ' * (len(_suite_stack)-1)}Suite: {name}")
+    return NIL
+
+def _pop_suite():
+    if _suite_stack:
+        _suite_stack.pop()
+    return NIL
+
+env["try-call"] = _try_call
+env["report-pass"] = _report_pass
+env["report-fail"] = _report_fail
+env["push-suite"] = _push_suite
+env["pop-suite"] = _pop_suite
+
+# Signal platform primitives
+env["signal?"] = sx_ref.is_signal
+env["make-signal"] = sx_ref.make_signal
+env["signal-value"] = sx_ref.signal_value
+env["signal-set-value!"] = sx_ref.signal_set_value
+env["signal-subscribers"] = sx_ref.signal_subscribers
+env["signal-add-sub!"] = sx_ref.signal_add_sub
+env["signal-remove-sub!"] = sx_ref.signal_remove_sub
+env["signal-deps"] = sx_ref.signal_deps
+env["signal-set-deps!"] = sx_ref.signal_set_deps
+env["identical?"] = sx_ref.is_identical
+env["island?"] = lambda x: isinstance(x, Island)
+
+# Scope primitives (used by signals.sx for reactive tracking)
+env["scope-push!"] = scope_push
+env["scope-pop!"] = scope_pop
+env["context"] = sx_context
+
+# Bootstrapped signal functions from sx_ref.py
+env["signal"] = sx_ref.signal
+env["deref"] = sx_ref.deref
+env["reset!"] = sx_ref.reset_b
+env["swap!"] = sx_ref.swap_b
+env["computed"] = sx_ref.computed
+env["effect"] = sx_ref.effect
+# batch has a bootstrapper issue with _batch_depth global variable access.
+# Wrap it to work correctly in the test context.
+def _batch(thunk):
+    sx_ref._batch_depth = getattr(sx_ref, '_batch_depth', 0) + 1
+    _invoke(thunk)
+    sx_ref._batch_depth -= 1
+    if sx_ref._batch_depth == 0:
+        queue = list(sx_ref._batch_queue)
+        sx_ref._batch_queue = []
+        seen = []
+        pending = []
+        for s in queue:
+            for sub in sx_ref.signal_subscribers(s):
+                if sub not in seen:
+                    seen.append(sub)
+                    pending.append(sub)
+        for sub in pending:
+            sub()
+    return NIL
+env["batch"] = _batch
+env["notify-subscribers"] = sx_ref.notify_subscribers
+env["flush-subscribers"] = sx_ref.flush_subscribers
+env["dispose-computed"] = sx_ref.dispose_computed
+env["with-island-scope"] = sx_ref.with_island_scope
+env["register-in-scope"] = sx_ref.register_in_scope
+env["invoke"] = _invoke
+env["callable?"] = sx_ref.is_callable
+
+# Load test framework
+with open(os.path.join(_HERE, "test-framework.sx")) as f:
+    for expr in parse_all(f.read()):
+        trampoline(eval_expr(expr, env))
+
+# Run tests
+print("=" * 60)
+print("Running test-signals.sx")
+print("=" * 60)
+
+with open(os.path.join(_HERE, "test-signals.sx")) as f:
+    for expr in parse_all(f.read()):
+        trampoline(eval_expr(expr, env))
+
+print("=" * 60)
+print(f"Results: {_pass_count} passed, {_fail_count} failed")
+print("=" * 60)
+sys.exit(1 if _fail_count > 0 else 0)
diff --git a/shared/sx/ref/signals.sx b/shared/sx/ref/signals.sx
index f7f6d11..bba2a02 100644
--- a/shared/sx/ref/signals.sx
+++ b/shared/sx/ref/signals.sx
@@ -9,6 +9,12 @@
 ;; layer (adapter-dom.sx) subscribes DOM nodes to signals. The server
 ;; adapter (adapter-html.sx) reads signal values without subscribing.
 ;;
+;; Reactive tracking and island lifecycle use the general scoped effects
+;; system (scope-push!/scope-pop!/context) instead of separate globals.
+;; Two scope names:
+;;   "sx-reactive"     — tracking context for computed/effect dep discovery
+;;   "sx-island-scope" — island disposable collector
+;;
 ;; Platform interface required:
 ;;   (make-signal value)       → Signal   — create signal container
 ;;   (signal? x)               → boolean  — type predicate
@@ -20,10 +26,10 @@
 ;;   (signal-deps s)           → list     — dependency list (for computed)
 ;;   (signal-set-deps! s deps) → void     — set dependency list
 ;;
-;; Global state required:
-;;   *tracking-context*        → nil | Effect/Computed currently evaluating
-;;   (set-tracking-context! c) → void
-;;   (get-tracking-context)    → context or nil
+;; Scope-based tracking (replaces TrackingContext platform primitives):
+;;   (scope-push! "sx-reactive" {:deps (list) :notify fn}) → void
+;;   (scope-pop! "sx-reactive")                            → void
+;;   (context "sx-reactive" nil)                           → dict or nil
 ;;
 ;; Runtime callable dispatch:
 ;;   (invoke f &rest args)     → any  — call f with args; handles both
@@ -58,12 +64,14 @@
   (fn ((s :as any))
     (if (not (signal? s))
       s  ;; non-signal values pass through
-      (let ((ctx (get-tracking-context)))
+      (let ((ctx (context "sx-reactive" nil)))
         (when ctx
           ;; Register this signal as a dependency of the current context
-          (tracking-context-add-dep! ctx s)
-          ;; Subscribe the context to this signal
-          (signal-add-sub! s (tracking-context-notify-fn ctx)))
+          (let ((dep-list (get ctx "deps"))
+                (notify-fn (get ctx "notify")))
+            (when (not (contains? dep-list s))
+              (append! dep-list s)
+              (signal-add-sub! s notify-fn))))
         (signal-value s)))))
 
 
@@ -117,19 +125,18 @@
                   (signal-deps s))
                 (signal-set-deps! s (list))
 
-                ;; Create tracking context for this computed
-                (let ((ctx (make-tracking-context recompute)))
-                  (let ((prev (get-tracking-context)))
-                    (set-tracking-context! ctx)
-                    (let ((new-val (invoke compute-fn)))
-                      (set-tracking-context! prev)
-                      ;; Save discovered deps
-                      (signal-set-deps! s (tracking-context-deps ctx))
-                      ;; Update value + notify downstream
-                      (let ((old (signal-value s)))
-                        (signal-set-value! s new-val)
-                        (when (not (identical? old new-val))
-                          (notify-subscribers s)))))))))
+                ;; Push scope-based tracking context for this computed
+                (let ((ctx (dict "deps" (list) "notify" recompute)))
+                  (scope-push! "sx-reactive" ctx)
+                  (let ((new-val (invoke compute-fn)))
+                    (scope-pop! "sx-reactive")
+                    ;; Save discovered deps
+                    (signal-set-deps! s (get ctx "deps"))
+                    ;; Update value + notify downstream
+                    (let ((old (signal-value s)))
+                      (signal-set-value! s new-val)
+                      (when (not (identical? old new-val))
+                        (notify-subscribers s))))))))
 
         ;; Initial computation
         (recompute)
@@ -163,16 +170,15 @@
                     deps)
                   (set! deps (list))
 
-                  ;; Track new deps
-                  (let ((ctx (make-tracking-context run-effect)))
-                    (let ((prev (get-tracking-context)))
-                      (set-tracking-context! ctx)
-                      (let ((result (invoke effect-fn)))
-                        (set-tracking-context! prev)
-                        (set! deps (tracking-context-deps ctx))
-                        ;; If effect returns a function, it's the cleanup
-                        (when (callable? result)
-                          (set! cleanup-fn result)))))))))
+                  ;; Push scope-based tracking context
+                  (let ((ctx (dict "deps" (list) "notify" run-effect)))
+                    (scope-push! "sx-reactive" ctx)
+                    (let ((result (invoke effect-fn)))
+                      (scope-pop! "sx-reactive")
+                      (set! deps (get ctx "deps"))
+                      ;; If effect returns a function, it's the cleanup
+                      (when (callable? result)
+                        (set! cleanup-fn result))))))))
 
         ;; Initial run
         (run-effect)
@@ -246,19 +252,13 @@
 
 
 ;; --------------------------------------------------------------------------
-;; 9. Tracking context
+;; 9. Reactive tracking context
 ;; --------------------------------------------------------------------------
 ;;
-;; A tracking context is an ephemeral object created during effect/computed
-;; evaluation to discover signal dependencies. Platform must provide:
-;;
-;;   (make-tracking-context notify-fn) → context
-;;   (tracking-context-deps ctx)       → list of signals
-;;   (tracking-context-add-dep! ctx s) → void (adds s to ctx's dep list)
-;;   (tracking-context-notify-fn ctx)  → the notify function
-;;
-;; These are platform primitives because the context is mutable state
-;; that must be efficient (often a Set in the host language).
+;; Tracking is now scope-based. computed/effect push a dict
+;; {:deps (list) :notify fn} onto the "sx-reactive" scope stack via
+;; scope-push!/scope-pop!. deref reads it via (context "sx-reactive" nil).
+;; No platform primitives needed — uses the existing scope infrastructure.
 
 
 ;; --------------------------------------------------------------------------
@@ -284,25 +284,24 @@
 ;; When an island is created, all signals, effects, and computeds created
 ;; within it are tracked. When the island is removed from the DOM, they
 ;; are all disposed.
-
-(define *island-scope* nil)
+;;
+;; Uses "sx-island-scope" scope name. The scope value is a collector
+;; function (fn (disposable) ...) that appends to the island's disposer list.
 
 (define with-island-scope :effects [mutation]
   (fn ((scope-fn :as lambda) (body-fn :as lambda))
-    (let ((prev *island-scope*))
-      (set! *island-scope* scope-fn)
-      (let ((result (body-fn)))
-        (set! *island-scope* prev)
-        result))))
+    (scope-push! "sx-island-scope" scope-fn)
+    (let ((result (body-fn)))
+      (scope-pop! "sx-island-scope")
+      result)))
 
 ;; Hook into signal/effect/computed creation for scope tracking.
-;; The platform's make-signal should call (register-in-scope s) if
-;; *island-scope* is non-nil.
 
 (define register-in-scope :effects [mutation]
   (fn ((disposable :as lambda))
-    (when *island-scope*
-      (*island-scope* disposable))))
+    (let ((collector (context "sx-island-scope" nil)))
+      (when collector
+        (invoke collector disposable)))))
 
 
 ;; ==========================================================================
diff --git a/shared/sx/ref/sx_ref.py b/shared/sx/ref/sx_ref.py
index e0f476a..d813b71 100644
--- a/shared/sx/ref/sx_ref.py
+++ b/shared/sx/ref/sx_ref.py
@@ -440,17 +440,6 @@ class _Signal:
         self.deps = []
 
 
-class _TrackingContext:
-    """Context for discovering signal dependencies."""
-    __slots__ = ("notify_fn", "deps")
-    def __init__(self, notify_fn):
-        self.notify_fn = notify_fn
-        self.deps = []
-
-
-_tracking_context = None
-
-
 def make_signal(value):
     return _Signal(value)
 
@@ -491,33 +480,6 @@ def signal_set_deps(s, deps):
         s.deps = list(deps) if isinstance(deps, list) else []
 
 
-def set_tracking_context(ctx):
-    global _tracking_context
-    _tracking_context = ctx
-
-
-def get_tracking_context():
-    global _tracking_context
-    return _tracking_context if _tracking_context is not None else NIL
-
-
-def make_tracking_context(notify_fn):
-    return _TrackingContext(notify_fn)
-
-
-def tracking_context_deps(ctx):
-    return ctx.deps if isinstance(ctx, _TrackingContext) else []
-
-
-def tracking_context_add_dep(ctx, s):
-    if isinstance(ctx, _TrackingContext) and s not in ctx.deps:
-        ctx.deps.append(s)
-
-
-def tracking_context_notify_fn(ctx):
-    return ctx.notify_fn if isinstance(ctx, _TrackingContext) else NIL
-
-
 def invoke(f, *args):
     """Call f with args — handles both native callables and SX lambdas.
 
@@ -3503,10 +3465,13 @@ def deref(s):
     if sx_truthy((not sx_truthy(is_signal(s)))):
         return s
     else:
-        ctx = get_tracking_context()
+        ctx = sx_context('sx-reactive', NIL)
         if sx_truthy(ctx):
-            tracking_context_add_dep(ctx, s)
-            signal_add_sub(s, tracking_context_notify_fn(ctx))
+            dep_list = get(ctx, 'deps')
+            notify_fn = get(ctx, 'notify')
+            if sx_truthy((not sx_truthy(contains_p(dep_list, s)))):
+                dep_list.append(s)
+                signal_add_sub(s, notify_fn)
         return signal_value(s)
 
 # reset!
@@ -3538,7 +3503,7 @@ def computed(compute_fn):
     recompute = _sx_fn(lambda : (
   for_each(lambda dep: signal_remove_sub(dep, recompute), signal_deps(s)),
   signal_set_deps(s, []),
-  (lambda ctx: (lambda prev: _sx_begin(set_tracking_context(ctx), (lambda new_val: _sx_begin(set_tracking_context(prev), signal_set_deps(s, tracking_context_deps(ctx)), (lambda old: _sx_begin(signal_set_value(s, new_val), (notify_subscribers(s) if sx_truthy((not sx_truthy(is_identical(old, new_val)))) else NIL)))(signal_value(s))))(invoke(compute_fn))))(get_tracking_context()))(make_tracking_context(recompute))
+  (lambda ctx: _sx_begin(scope_push('sx-reactive', ctx), (lambda new_val: _sx_begin(scope_pop('sx-reactive'), signal_set_deps(s, get(ctx, 'deps')), (lambda old: _sx_begin(signal_set_value(s, new_val), (notify_subscribers(s) if sx_truthy((not sx_truthy(is_identical(old, new_val)))) else NIL)))(signal_value(s))))(invoke(compute_fn))))({'deps': [], 'notify': recompute})
 )[-1])
     recompute()
     register_in_scope(lambda : dispose_computed(s))
@@ -3550,7 +3515,7 @@ def effect(effect_fn):
     _cells['deps'] = []
     _cells['disposed'] = False
     _cells['cleanup_fn'] = NIL
-    run_effect = lambda : (_sx_begin((invoke(_cells['cleanup_fn']) if sx_truthy(_cells['cleanup_fn']) else NIL), for_each(lambda dep: signal_remove_sub(dep, run_effect), _cells['deps']), _sx_cell_set(_cells, 'deps', []), (lambda ctx: (lambda prev: _sx_begin(set_tracking_context(ctx), (lambda result: _sx_begin(set_tracking_context(prev), _sx_cell_set(_cells, 'deps', tracking_context_deps(ctx)), (_sx_cell_set(_cells, 'cleanup_fn', result) if sx_truthy(is_callable(result)) else NIL)))(invoke(effect_fn))))(get_tracking_context()))(make_tracking_context(run_effect))) if sx_truthy((not sx_truthy(_cells['disposed']))) else NIL)
+    run_effect = lambda : (_sx_begin((invoke(_cells['cleanup_fn']) if sx_truthy(_cells['cleanup_fn']) else NIL), for_each(lambda dep: signal_remove_sub(dep, run_effect), _cells['deps']), _sx_cell_set(_cells, 'deps', []), (lambda ctx: _sx_begin(scope_push('sx-reactive', ctx), (lambda result: _sx_begin(scope_pop('sx-reactive'), _sx_cell_set(_cells, 'deps', get(ctx, 'deps')), (_sx_cell_set(_cells, 'cleanup_fn', result) if sx_truthy(is_callable(result)) else NIL)))(invoke(effect_fn))))({'deps': [], 'notify': run_effect})) if sx_truthy((not sx_truthy(_cells['disposed']))) else NIL)
     run_effect()
     dispose_fn = _sx_fn(lambda : (
   _sx_cell_set(_cells, 'disposed', True),
@@ -3610,21 +3575,18 @@ def dispose_computed(s):
         return signal_set_deps(s, [])
     return NIL
 
-# *island-scope*
-_island_scope = NIL
-
 # with-island-scope
 def with_island_scope(scope_fn, body_fn):
-    prev = _island_scope
-    _island_scope = scope_fn
+    scope_push('sx-island-scope', scope_fn)
     result = body_fn()
-    _island_scope = prev
+    scope_pop('sx-island-scope')
     return result
 
 # register-in-scope
 def register_in_scope(disposable):
-    if sx_truthy(_island_scope):
-        return _island_scope(disposable)
+    collector = sx_context('sx-island-scope', NIL)
+    if sx_truthy(collector):
+        return invoke(collector, disposable)
     return NIL
 
 # with-marsh-scope
diff --git a/shared/sx/ref/test-signals.sx b/shared/sx/ref/test-signals.sx
index 3ae5695..189a1c3 100644
--- a/shared/sx/ref/test-signals.sx
+++ b/shared/sx/ref/test-signals.sx
@@ -171,3 +171,46 @@
       (list "wrap" children))
     (assert-equal (list "wrap" (list "a" "b"))
                   (~wrapper "a" "b"))))
+
+
+;; --------------------------------------------------------------------------
+;; Scope integration — reactive tracking uses scope-push!/scope-pop!
+;; --------------------------------------------------------------------------
+
+(defsuite "scope integration"
+  (deftest "deref outside reactive scope does not subscribe"
+    (let ((s (signal 42)))
+      ;; Reading outside any reactive context should not add subscribers
+      (assert-equal 42 (deref s))
+      (assert-equal 0 (len (signal-subscribers s)))))
+
+  (deftest "computed uses scope for tracking"
+    (let ((a (signal 1))
+          (b (signal 2))
+          (sum (computed (fn () (+ (deref a) (deref b))))))
+      ;; Each signal should have exactly 1 subscriber (the computed's recompute)
+      (assert-equal 1 (len (signal-subscribers a)))
+      (assert-equal 1 (len (signal-subscribers b)))
+      ;; Verify computed value
+      (assert-equal 3 (deref sum))))
+
+  (deftest "nested effects with overlapping deps use scope correctly"
+    (let ((shared (signal 0))
+          (inner-only (signal 0))
+          (outer-count (signal 0))
+          (inner-count (signal 0)))
+      ;; Outer effect tracks shared
+      (effect (fn () (do (deref shared) (swap! outer-count inc))))
+      ;; Inner effect tracks shared AND inner-only
+      (effect (fn () (do (deref shared) (deref inner-only) (swap! inner-count inc))))
+      ;; Both ran once
+      (assert-equal 1 (deref outer-count))
+      (assert-equal 1 (deref inner-count))
+      ;; Changing shared triggers both
+      (reset! shared 1)
+      (assert-equal 2 (deref outer-count))
+      (assert-equal 2 (deref inner-count))
+      ;; Changing inner-only triggers only inner
+      (reset! inner-only 1)
+      (assert-equal 2 (deref outer-count))
+      (assert-equal 3 (deref inner-count)))))