diff --git a/.publish/ai/package.json b/.publish/ai/package.json
index 1b8f8489..8c12fc31 100644
--- a/.publish/ai/package.json
+++ b/.publish/ai/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/ai",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "Zero-dependency Claude (Anthropic) client for WrNexus apps.",
   "license": "MIT",
diff --git a/.publish/authz/package.json b/.publish/authz/package.json
index c6b96741..c32c98b4 100644
--- a/.publish/authz/package.json
+++ b/.publish/authz/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/authz",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/authz — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/cli/package.json b/.publish/cli/package.json
index 22b9f125..bc09ae28 100644
--- a/.publish/cli/package.json
+++ b/.publish/cli/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/cli",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/cli — part of the WrNexus framework.",
   "license": "MIT",
@@ -28,16 +28,16 @@
     "wrnexus": "./dist/index.js"
   },
   "dependencies": {
-    "@wrnexus/core": "^0.2.30",
-    "@wrnexus/router": "^0.2.30",
-    "@wrnexus/csr": "^0.2.30",
-    "@wrnexus/compiler": "^0.2.30",
-    "@wrnexus/styles": "^0.2.30",
-    "@wrnexus/dev-server": "^0.2.30",
-    "@wrnexus/ui": "^0.2.30",
-    "@wrnexus/validation": "^0.2.30",
-    "@wrnexus/i18n": "^0.2.30",
-    "@wrnexus/db": "^0.2.30"
+    "@wrnexus/core": "^0.2.31",
+    "@wrnexus/router": "^0.2.31",
+    "@wrnexus/csr": "^0.2.31",
+    "@wrnexus/compiler": "^0.2.31",
+    "@wrnexus/styles": "^0.2.31",
+    "@wrnexus/dev-server": "^0.2.31",
+    "@wrnexus/ui": "^0.2.31",
+    "@wrnexus/validation": "^0.2.31",
+    "@wrnexus/i18n": "^0.2.31",
+    "@wrnexus/db": "^0.2.31"
   },
   "files": [
     "dist"
diff --git a/.publish/compiler/package.json b/.publish/compiler/package.json
index 52525cf5..e5a5c01c 100644
--- a/.publish/compiler/package.json
+++ b/.publish/compiler/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/compiler",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/compiler — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/core/package.json b/.publish/core/package.json
index 9d6a72d2..99291dae 100644
--- a/.publish/core/package.json
+++ b/.publish/core/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/core",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/core — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/csr/package.json b/.publish/csr/package.json
index 18d8d7eb..1d740a6e 100644
--- a/.publish/csr/package.json
+++ b/.publish/csr/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/csr",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/csr — part of the WrNexus framework.",
   "license": "MIT",
@@ -21,7 +21,7 @@
     }
   },
   "dependencies": {
-    "@wrnexus/core": "^0.2.30"
+    "@wrnexus/core": "^0.2.31"
   },
   "files": [
     "dist"
diff --git a/.publish/db/package.json b/.publish/db/package.json
index a4038caa..d2bb4a36 100644
--- a/.publish/db/package.json
+++ b/.publish/db/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/db",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/db — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/dev-server/package.json b/.publish/dev-server/package.json
index d7535bf6..ea690999 100644
--- a/.publish/dev-server/package.json
+++ b/.publish/dev-server/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/dev-server",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/dev-server — part of the WrNexus framework.",
   "license": "MIT",
@@ -25,18 +25,18 @@
     }
   },
   "dependencies": {
-    "@wrnexus/core": "^0.2.30",
-    "@wrnexus/router": "^0.2.30",
-    "@wrnexus/ssr": "^0.2.30",
-    "@wrnexus/csr": "^0.2.30",
-    "@wrnexus/compiler": "^0.2.30",
-    "@wrnexus/styles": "^0.2.30",
-    "@wrnexus/ui": "^0.2.30",
-    "@wrnexus/validation": "^0.2.30",
-    "@wrnexus/i18n": "^0.2.30",
-    "@wrnexus/db": "^0.2.30",
-    "@wrnexus/pubsub": "^0.2.30",
-    "@wrnexus/uploader": "^0.2.30"
+    "@wrnexus/core": "^0.2.31",
+    "@wrnexus/router": "^0.2.31",
+    "@wrnexus/ssr": "^0.2.31",
+    "@wrnexus/csr": "^0.2.31",
+    "@wrnexus/compiler": "^0.2.31",
+    "@wrnexus/styles": "^0.2.31",
+    "@wrnexus/ui": "^0.2.31",
+    "@wrnexus/validation": "^0.2.31",
+    "@wrnexus/i18n": "^0.2.31",
+    "@wrnexus/db": "^0.2.31",
+    "@wrnexus/pubsub": "^0.2.31",
+    "@wrnexus/uploader": "^0.2.31"
   },
   "files": [
     "dist"
diff --git a/.publish/encryption/package.json b/.publish/encryption/package.json
index 2e77b39d..ddf393c2 100644
--- a/.publish/encryption/package.json
+++ b/.publish/encryption/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/encryption",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/encryption — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/helpers/package.json b/.publish/helpers/package.json
index f61799ad..b5d5912b 100644
--- a/.publish/helpers/package.json
+++ b/.publish/helpers/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/helpers",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "Safe convenience helpers for WrNexus request contexts and common application flows.",
   "license": "MIT",
@@ -21,7 +21,7 @@
     }
   },
   "dependencies": {
-    "@wrnexus/core": "^0.2.30"
+    "@wrnexus/core": "^0.2.31"
   },
   "files": [
     "dist"
diff --git a/.publish/i18n/package.json b/.publish/i18n/package.json
index 286379d4..96ebfa1d 100644
--- a/.publish/i18n/package.json
+++ b/.publish/i18n/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/i18n",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/i18n — part of the WrNexus framework.",
   "license": "MIT",
@@ -21,7 +21,7 @@
     }
   },
   "dependencies": {
-    "@wrnexus/core": "^0.2.30"
+    "@wrnexus/core": "^0.2.31"
   },
   "files": [
     "dist"
diff --git a/.publish/jwt/package.json b/.publish/jwt/package.json
index b0dfd15b..fe9e1f9c 100644
--- a/.publish/jwt/package.json
+++ b/.publish/jwt/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/jwt",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/jwt — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/mobile/package.json b/.publish/mobile/package.json
index a9a35491..00c92765 100644
--- a/.publish/mobile/package.json
+++ b/.publish/mobile/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/mobile",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/mobile — part of the WrNexus framework.",
   "license": "MIT",
@@ -21,7 +21,7 @@
     }
   },
   "dependencies": {
-    "@wrnexus/native": "^0.2.30"
+    "@wrnexus/native": "^0.2.31"
   },
   "files": [
     "dist"
diff --git a/.publish/native/package.json b/.publish/native/package.json
index 8fb55786..b29abc42 100644
--- a/.publish/native/package.json
+++ b/.publish/native/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/native",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/native — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/oauth/package.json b/.publish/oauth/package.json
index c4b01dce..e4368bb9 100644
--- a/.publish/oauth/package.json
+++ b/.publish/oauth/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/oauth",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/oauth — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/pubsub/package.json b/.publish/pubsub/package.json
index 698b072b..62def059 100644
--- a/.publish/pubsub/package.json
+++ b/.publish/pubsub/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/pubsub",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/pubsub — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/queue/package.json b/.publish/queue/package.json
index b77d179b..8cb6b62d 100644
--- a/.publish/queue/package.json
+++ b/.publish/queue/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/queue",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/queue — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/reactive/package.json b/.publish/reactive/package.json
index 06d76545..11cb802b 100644
--- a/.publish/reactive/package.json
+++ b/.publish/reactive/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/reactive",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/reactive — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/router/package.json b/.publish/router/package.json
index af7b04c7..51cdc407 100644
--- a/.publish/router/package.json
+++ b/.publish/router/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/router",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/router — part of the WrNexus framework.",
   "license": "MIT",
@@ -21,8 +21,8 @@
     }
   },
   "dependencies": {
-    "@wrnexus/compiler": "^0.2.30",
-    "@wrnexus/core": "^0.2.30"
+    "@wrnexus/compiler": "^0.2.31",
+    "@wrnexus/core": "^0.2.31"
   },
   "files": [
     "dist"
diff --git a/.publish/ssr/package.json b/.publish/ssr/package.json
index 147047c5..68c399b5 100644
--- a/.publish/ssr/package.json
+++ b/.publish/ssr/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/ssr",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/ssr — part of the WrNexus framework.",
   "license": "MIT",
@@ -21,7 +21,7 @@
     }
   },
   "dependencies": {
-    "@wrnexus/core": "^0.2.30"
+    "@wrnexus/core": "^0.2.31"
   },
   "files": [
     "dist"
diff --git a/.publish/styles/package.json b/.publish/styles/package.json
index b57e79d9..ad8391d8 100644
--- a/.publish/styles/package.json
+++ b/.publish/styles/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/styles",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/styles — part of the WrNexus framework.",
   "license": "MIT",
@@ -21,7 +21,7 @@
     }
   },
   "dependencies": {
-    "@wrnexus/uploader": "^0.2.30"
+    "@wrnexus/uploader": "^0.2.31"
   },
   "files": [
     "dist"
diff --git a/.publish/test/package.json b/.publish/test/package.json
index 4a08082a..b3a55130 100644
--- a/.publish/test/package.json
+++ b/.publish/test/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/test",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/test — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/tracking/package.json b/.publish/tracking/package.json
index c6be9e36..59d3de43 100644
--- a/.publish/tracking/package.json
+++ b/.publish/tracking/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/tracking",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/tracking — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/.publish/ui/package.json b/.publish/ui/package.json
index 752e7ae9..0861f921 100644
--- a/.publish/ui/package.json
+++ b/.publish/ui/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/ui",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/ui — part of the WrNexus framework.",
   "license": "MIT",
@@ -22,7 +22,7 @@
     "./ui.css": "./ui.css"
   },
   "dependencies": {
-    "@wrnexus/core": "^0.2.30"
+    "@wrnexus/core": "^0.2.31"
   },
   "files": [
     "dist",
diff --git a/.publish/uploader/package.json b/.publish/uploader/package.json
index cf24d2f5..1a6414b5 100644
--- a/.publish/uploader/package.json
+++ b/.publish/uploader/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/uploader",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/uploader — part of the WrNexus framework.",
   "license": "MIT",
@@ -21,7 +21,7 @@
     }
   },
   "dependencies": {
-    "@wrnexus/core": "^0.2.30"
+    "@wrnexus/core": "^0.2.31"
   },
   "files": [
     "dist"
diff --git a/.publish/validation/package.json b/.publish/validation/package.json
index 8e2d3758..6e2ef57d 100644
--- a/.publish/validation/package.json
+++ b/.publish/validation/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/validation",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "description": "@wrnexus/validation — part of the WrNexus framework.",
   "license": "MIT",
diff --git a/packages/ai/package.json b/packages/ai/package.json
index b119ebd8..182e5687 100644
--- a/packages/ai/package.json
+++ b/packages/ai/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/ai",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "description": "Zero-dependency Claude (Anthropic) client for WrNexus apps.",
diff --git a/packages/authz/package.json b/packages/authz/package.json
index eaa572b9..8ca553a8 100644
--- a/packages/authz/package.json
+++ b/packages/authz/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/authz",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",
diff --git a/packages/cli/package.json b/packages/cli/package.json
index 781c7277..47e61186 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/cli",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
diff --git a/packages/cli/src/update.ts b/packages/cli/src/update.ts
index e15020d9..47ccb7be 100644
--- a/packages/cli/src/update.ts
+++ b/packages/cli/src/update.ts
@@ -348,6 +348,15 @@ const MIGRATIONS: Migration[] = [
       // No generated application files require automatic migration.
     },
   },
+  {
+    version: "0.2.31",
+    id: "lifecycle-improvements",
+    description:
+      "Adds component functions, lifecycle hooks, state watchers, optimized behavior cleanup, and CSR navigation lifecycle support.",
+    apply() {
+      // No generated application files require automatic migration.
+    },
+  },
 ];
 
 /** Release tooling uses this to require an explicit migration entry per version. */
diff --git a/packages/compiler/package.json b/packages/compiler/package.json
index 363f0048..c99b5de1 100644
--- a/packages/compiler/package.json
+++ b/packages/compiler/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/compiler",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
diff --git a/packages/compiler/src/codegen.ts b/packages/compiler/src/codegen.ts
index 0575cf4e..ddc9da00 100644
--- a/packages/compiler/src/codegen.ts
+++ b/packages/compiler/src/codegen.ts
@@ -78,8 +78,22 @@ function renderAttr(attr: Attr): string {
 }
 
 function eventAttribute(name: string): string {
-  if (name.startsWith("browser-")) return `data-on-wrnexus-browser-${name.slice(8)}`;
-  if (name.startsWith("mobile-")) return `data-on-wrnexus-mobile-${name.slice(7)}`;
+  if (name.startsWith("window:")) {
+    return `data-on-window-${name.slice("window:".length)}`;
+  }
+
+  if (name.startsWith("document:")) {
+    return `data-on-document-${name.slice("document:".length)}`;
+  }
+
+  if (name.startsWith("browser-")) {
+    return `data-on-wrnexus-browser-${name.slice(8)}`;
+  }
+
+  if (name.startsWith("mobile-")) {
+    return `data-on-wrnexus-mobile-${name.slice(7)}`;
+  }
+
   return `data-on-${name}`;
 }
 
@@ -437,7 +451,9 @@ function renderNestedComponentInvocation(
     .filter((attr) => attr.name !== "data-component")
     .map((attr) => {
       if (attr.event) {
-        return ` ${eventAttribute(attr.name)}="${compileAttrValue(attr.value, ctx)}"`;
+        return (
+          escLit(` ${eventAttribute(attr.name)}="`) + escLit(attrEscape(attr.value)) + escLit(`"`)
+        );
       }
 
       if (attr.boolean) {
@@ -790,6 +806,19 @@ interface CompCtx {
   loopVars?: Set<string>;
 }
 
+interface ComponentBehavior {
+  functions: string;
+  lifecycle: {
+    mount?: string;
+    update?: string;
+    unmount?: string;
+  };
+  watches: Array<{
+    state: string;
+    body: string;
+  }>;
+}
+
 /** Parse a `data-for="item in list"` / `"item, i in list"` directive value. */
 export function parseForExpr(value: string): { item: string; index?: string; list: string } | null {
   const m = /^\s*([A-Za-z_$][\w$]*)\s*(?:,\s*([A-Za-z_$][\w$]*)\s*)?\s+in\s+([\s\S]+?)\s*$/.exec(
@@ -861,6 +890,44 @@ function escLit(s: string): string {
   return s.replace(/\\/g, "\\\\").replace(/`/g, "\\`").replace(/\$\{/g, "\\${");
 }
 
+function componentBehavior(ast: PageAst): ComponentBehavior | null {
+  const functions = ast.functions
+    .map((body) => body.trim())
+    .filter(Boolean)
+    .join("\n\n");
+
+  const lifecycle = {
+    ...(ast.lifecycle.mount?.trim() ? { mount: ast.lifecycle.mount.trim() } : {}),
+
+    ...(ast.lifecycle.update?.trim() ? { update: ast.lifecycle.update.trim() } : {}),
+
+    ...(ast.lifecycle.unmount?.trim() ? { unmount: ast.lifecycle.unmount.trim() } : {}),
+  };
+
+  const watches = ast.watches.map((watch) => ({
+    state: watch.state,
+    body: watch.body.trim(),
+  }));
+
+  if (!functions && Object.keys(lifecycle).length === 0 && watches.length === 0) {
+    return null;
+  }
+
+  return {
+    functions,
+    lifecycle,
+    watches,
+  };
+}
+
+function behaviorAttribute(behavior: ComponentBehavior | null): string {
+  if (!behavior) {
+    return "";
+  }
+
+  return ` data-wrn-behavior="${attrEscape(JSON.stringify(behavior))}"`;
+}
+
 const INTERP_RE = /\{([^{}]+)\}/g;
 
 function exprRefsState(expr: string, stateNames: Set<string>): boolean {
@@ -971,7 +1038,7 @@ function renderComponentNode(node: ViewNode, ctx: CompCtx): string {
     .filter((a) => a.name !== "class" && !a.name.startsWith("class:"))
     .map((a) => {
       if (a.event) {
-        return ` ${eventAttribute(a.name)}="${compileAttrValue(a.value, ctx)}"`;
+        return ` ${eventAttribute(a.name)}="${escLit(attrEscape(a.value))}"`;
       }
 
       if (a.boolean) {
@@ -1066,12 +1133,17 @@ function generateComponent(ast: PageAst): string {
   // A component needs a reactive scope only when it has state or event handlers.
   // Prop-driven text/attributes are baked server-side, so static components ship
   // no JavaScript at all.
-  const needsScope = ast.states.length > 0 || viewHasEvents(ast.view);
+  const behavior = componentBehavior(ast);
+
+  const needsScope = ast.states.length > 0 || viewHasEvents(ast.view) || behavior !== null;
+
   const scopeKeys = [
     ...effectiveProps.map((prop) => prop.name),
     ...ast.states.map((state) => state.name),
   ];
 
+  const behaviorAttr = behaviorAttribute(behavior);
+
   const decls: string[] = [];
   for (const prop of effectiveProps) {
     decls.push(
@@ -1083,7 +1155,7 @@ function generateComponent(ast: PageAst): string {
   }
 
   const returnExpr = needsScope
-    ? "`" + styleTag + '<div data-scope="${__scope}">' + viewCode + "</div>`"
+    ? "`" + styleTag + `<div data-scope="\${__scope}"${behaviorAttr}>` + viewCode + "</div>`"
     : "`" + styleTag + viewCode + "`";
 
   const scopeLine =
@@ -1098,6 +1170,11 @@ function generateComponent(ast: PageAst): string {
   } else {
     out.push(`export const __wrnexusComponent = ${JSON.stringify(ast.name)};`);
   }
+
+  if (behavior) {
+    out.push(`export const __wrnexusBehavior = ${JSON.stringify(behavior, null, 2)};`);
+  }
+
   out.push(`function __coerce(v: any, def: any): any {
   if (v === undefined || v === null) return def;
   if (typeof def === "number") return Number(v);
diff --git a/packages/compiler/src/parser.ts b/packages/compiler/src/parser.ts
index 38fbf65d..92784309 100644
--- a/packages/compiler/src/parser.ts
+++ b/packages/compiler/src/parser.ts
@@ -105,6 +105,19 @@ export interface ModeFunctionsBlock {
   body: string;
 }
 
+export type LifecycleHookName = "mount" | "update" | "unmount";
+
+export interface LifecycleBlock {
+  mount?: string;
+  update?: string;
+  unmount?: string;
+}
+
+export interface WatchBlock {
+  state: string;
+  body: string;
+}
+
 export interface RealtimeHandler {
   event: string;
   args: string[];
@@ -141,6 +154,8 @@ export interface PageAst {
   functions: string[];
   dataApis: DataApiBlock[];
   modeFunctions: ModeFunctionsBlock[];
+  lifecycle: LifecycleBlock;
+  watches: WatchBlock[];
   apis: ApiBlock[];
   realtimes: RealtimeBlock[];
 }
@@ -210,6 +225,8 @@ export function parse(source: string): PageAst {
     const functions: string[] = [];
     const dataApis: DataApiBlock[] = [];
     const modeFunctions: ModeFunctionsBlock[] = [];
+    const lifecycle: LifecycleBlock = {};
+    const watches: WatchBlock[] = [];
     const apis: ApiBlock[] = [];
     const realtimes: RealtimeBlock[] = [];
 
@@ -339,6 +356,52 @@ export function parse(source: string): PageAst {
           styles.push(lx.readBalancedBraces());
           break;
         }
+        case "lifecycle": {
+          lx.next();
+          expect("lbrace");
+
+          while (lx.peek().type !== "rbrace") {
+            const hook = lx.peek();
+
+            if (hook.type === "eof") {
+              throw new ParseError("Unexpected end of input inside lifecycle block");
+            }
+
+            if (hook.type !== "ident") {
+              throw new ParseError(`Expected a lifecycle hook at offset ${hook.pos}`);
+            }
+
+            if (hook.value !== "mount" && hook.value !== "update" && hook.value !== "unmount") {
+              throw new ParseError(`Unknown lifecycle hook '${hook.value}' at offset ${hook.pos}`);
+            }
+
+            const hookName = hook.value as LifecycleHookName;
+
+            lx.next();
+
+            if (lifecycle[hookName] !== undefined) {
+              throw new ParseError(`Duplicate lifecycle hook '${hookName}' at offset ${hook.pos}`);
+            }
+
+            lifecycle[hookName] = lx.readBalancedBraces();
+          }
+
+          expect("rbrace");
+          break;
+        }
+        case "watch": {
+          lx.next();
+
+          const stateName = expect("ident").value;
+          const body = lx.readBalancedBraces();
+
+          watches.push({
+            state: stateName,
+            body,
+          });
+
+          break;
+        }
         case "functions": {
           lx.next();
           functions.push(lx.readBalancedBraces());
@@ -350,6 +413,14 @@ export function parse(source: string): PageAst {
     }
     expect("rbrace");
 
+    const declaredStates = new Set(states.map((state) => state.name));
+
+    for (const watcher of watches) {
+      if (!declaredStates.has(watcher.state)) {
+        throw new ParseError(`Cannot watch undeclared state '${watcher.state}'`);
+      }
+    }
+
     return {
       type: "page",
       kind,
@@ -363,6 +434,8 @@ export function parse(source: string): PageAst {
       functions,
       dataApis,
       modeFunctions,
+      lifecycle,
+      watches,
       apis,
       realtimes,
     };
diff --git a/packages/compiler/test/compiler.test.ts b/packages/compiler/test/compiler.test.ts
index 19875fde..03fee9de 100644
--- a/packages/compiler/test/compiler.test.ts
+++ b/packages/compiler/test/compiler.test.ts
@@ -243,3 +243,196 @@ layout AppLayout {
 
   expect(output).toContain("export function render");
 });
+test("parses component lifecycle hooks", () => {
+  const ast = parse(`
+component BackToTop {
+  state visible = false
+
+  lifecycle {
+    mount {
+      visible = true
+    }
+
+    update {
+      console.log(visible)
+    }
+
+    unmount {
+      visible = false
+    }
+  }
+
+  view {
+    <button>Top</button>
+  }
+}
+`);
+
+  expect(ast.lifecycle.mount).toContain("visible = true");
+
+  expect(ast.lifecycle.update).toContain("console.log(visible)");
+
+  expect(ast.lifecycle.unmount).toContain("visible = false");
+});
+test("parses state watchers", () => {
+  const ast = parse(`
+component Menu {
+  state open = false
+
+  watch open {
+    console.log("Open changed", open)
+  }
+
+  view {
+    <button>{open}</button>
+  }
+}
+`);
+
+  expect(ast.watches).toEqual([
+    {
+      state: "open",
+      body: expect.stringContaining('console.log("Open changed", open)'),
+    },
+  ]);
+});
+test("rejects watching an undeclared state", () => {
+  expect(() =>
+    parse(`
+component Broken {
+  watch missing {
+    console.log(missing)
+  }
+
+  view {
+    <div>Broken</div>
+  }
+}
+`),
+  ).toThrow("Cannot watch undeclared state 'missing'");
+});
+test("rejects unknown lifecycle hooks", () => {
+  expect(() =>
+    parse(`
+component Broken {
+  lifecycle {
+    created {
+      console.log("invalid")
+    }
+  }
+
+  view {
+    <div>Broken</div>
+  }
+}
+`),
+  ).toThrow("Unknown lifecycle hook 'created'");
+});
+test("component functions compile into browser behavior metadata", () => {
+  const output = generate(
+    parse(`
+component Counter {
+  state count = 0
+
+  functions {
+    function increment() {
+      count += 1
+    }
+  }
+
+  view {
+    <button @click="increment()">
+      {count}
+    </button>
+  }
+}
+`),
+  );
+
+  expect(output).toContain("data-wrn-behavior");
+
+  expect(output).toContain("function increment()");
+
+  expect(output).toContain("export const __wrnexusBehavior");
+});
+test("component lifecycle hooks compile into behavior metadata", () => {
+  const output = generate(
+    parse(`
+component LifecycleTest {
+  state ready = false
+
+  lifecycle {
+    mount {
+      ready = true
+    }
+
+    update {
+      console.log(ready)
+    }
+
+    unmount {
+      ready = false
+    }
+  }
+
+  view {
+    <div>{ready}</div>
+  }
+}
+`),
+  );
+
+  expect(output).toContain("&quot;mount&quot;");
+
+  expect(output).toContain("&quot;update&quot;");
+
+  expect(output).toContain("&quot;unmount&quot;");
+});
+test("component watchers compile into behavior metadata", () => {
+  const output = generate(
+    parse(`
+component WatchTest {
+  state visible = false
+
+  watch visible {
+    console.log("changed", visible)
+  }
+
+  view {
+    <div>{visible}</div>
+  }
+}
+`),
+  );
+
+  expect(output).toContain("&quot;state&quot;:&quot;visible&quot;");
+
+  expect(output).toContain("console.log");
+});
+test("behavior-only components still receive a reactive scope", () => {
+  const output = generate(
+    parse(`
+component BehaviorOnly {
+  functions {
+    function sayHello() {
+      console.log("hello")
+    }
+  }
+
+  lifecycle {
+    mount {
+      sayHello()
+    }
+  }
+
+  view {
+    <div>Hello</div>
+  }
+}
+`),
+  );
+
+  expect(output).toContain("data-scope");
+
+  expect(output).toContain("data-wrn-behavior");
+});
diff --git a/packages/core/package.json b/packages/core/package.json
index 0a518a6a..4abf7cb0 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/core",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
diff --git a/packages/csr/package.json b/packages/csr/package.json
index 22c11e45..c113a266 100644
--- a/packages/csr/package.json
+++ b/packages/csr/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/csr",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
diff --git a/packages/csr/src/nav-runtime.ts b/packages/csr/src/nav-runtime.ts
index 00b5d3c6..57412f3b 100644
--- a/packages/csr/src/nav-runtime.ts
+++ b/packages/csr/src/nav-runtime.ts
@@ -4,127 +4,421 @@
  * Progressive enhancement over normal links: intercepts same-origin `<a>`
  * clicks, fetches the target page's HTML, swaps the `#app` container in place,
  * updates history/title/scroll, ensures any framework runtimes the new page
- * needs are present, and re-hydrates. Anything unexpected (cross-origin,
- * modified click, non-HTML response, missing `#app`) falls back to a full
- * browser navigation, so behaviour degrades safely.
+ * needs are present, and re-hydrates.
  *
- * Data "loaders": pages load their data on the server (SSR `api` bindings), so
- * the fetched HTML already contains fresh data — no separate client loader is
- * needed. Client-side (`csr`) bindings and reactive scopes re-hydrate after the
- * swap. Programmatic navigation is exposed as `window.__wrnexusNavigate(url)`.
+ * Before replacing the current page, component lifecycle behaviors are
+ * explicitly disposed. This ensures `unmount` hooks and watcher cleanups run
+ * before the old DOM is removed.
+ *
+ * Programmatic navigation is exposed as:
+ *
+ *   window.__wrnexusNavigate(url)
  */
 
 export const NAV_RUNTIME = String.raw`
 (function () {
-  if (!window.history || !history.pushState || !window.fetch || !window.DOMParser) return;
-  if (window.__wrnexusNavInstalled) return;
+  if (
+    !window.history ||
+    !history.pushState ||
+    !window.fetch ||
+    !window.DOMParser
+  ) {
+    return;
+  }
+
+  if (window.__wrnexusNavInstalled) {
+    return;
+  }
+
   window.__wrnexusNavInstalled = true;
 
   var APP_ID = "app";
+  var inFlight = null;
 
-  function pathOf(src) { return String(src).split("?")[0]; }
+  function pathOf(src) {
+    return String(src).split("?")[0];
+  }
+
+  function isLocalLink(anchor) {
+    if (
+      !anchor ||
+      anchor.hasAttribute("download") ||
+      anchor.hasAttribute("data-no-nav")
+    ) {
+      return false;
+    }
+
+    if (anchor.target && anchor.target !== "_self") {
+      return false;
+    }
+
+    if (anchor.origin !== location.origin) {
+      return false;
+    }
+
+    var href = anchor.getAttribute("href");
+
+    if (!href || href.charAt(0) === "#") {
+      return false;
+    }
+
+    var rel = (
+      anchor.getAttribute("rel") || ""
+    ).toLowerCase();
 
-  function isLocalLink(a) {
-    if (!a || a.hasAttribute("download") || a.hasAttribute("data-no-nav")) return false;
-    if (a.target && a.target !== "_self") return false;
-    if (a.origin !== location.origin) return false;
-    var href = a.getAttribute("href");
-    if (!href || href.charAt(0) === "#") return false;
-    var rel = (a.getAttribute("rel") || "").toLowerCase();
     return rel.indexOf("external") === -1;
   }
 
   function loadedScriptPaths() {
-    var set = {};
-    document.querySelectorAll("script[src]").forEach(function (s) {
-      var src = s.getAttribute("src");
-      if (src) set[pathOf(src)] = true;
-    });
-    return set;
+    var loaded = {};
+
+    document
+      .querySelectorAll("script[src]")
+      .forEach(function (script) {
+        var src = script.getAttribute("src");
+
+        if (src) {
+          loaded[pathOf(src)] = true;
+        }
+      });
+
+    return loaded;
   }
 
-  // Append any /__wrnexus/* runtime the incoming page declares but the current
-  // document has not loaded yet. Fresh scripts self-initialise on load.
+  /**
+   * Append framework runtimes declared by the incoming document but not
+   * currently loaded.
+   */
   function ensureScripts(doc) {
     var loaded = loadedScriptPaths();
-    doc.querySelectorAll("script[src]").forEach(function (s) {
-      var src = s.getAttribute("src");
-      if (!src || loaded[pathOf(src)]) return;
-      loaded[pathOf(src)] = true;
-      var el = document.createElement("script");
-      el.src = src;
-      el.async = false; // preserve execution order (e.g. schemas.js before validate.js)
-      document.body.appendChild(el);
-    });
+
+    doc
+      .querySelectorAll("script[src]")
+      .forEach(function (script) {
+        var src = script.getAttribute("src");
+
+        if (!src || loaded[pathOf(src)]) {
+          return;
+        }
+
+        loaded[pathOf(src)] = true;
+
+        var element =
+          document.createElement("script");
+
+        element.src = src;
+        element.async = false;
+
+        document.body.appendChild(element);
+      });
   }
 
-  // Re-hydrate already-loaded runtimes against the swapped-in DOM. Every
-  // entrypoint is idempotent, so this is safe even when a fresh script also
-  // self-initialises the same nodes.
-  function rehydrate() {
-    try { if (window.__wrnexusHydrateScopes) window.__wrnexusHydrateScopes(document); } catch (e) {}
-    try { if (window.__wrnexusHydrateCsrFetches) window.__wrnexusHydrateCsrFetches(document); } catch (e) {}
-    try { if (window.__wireValidate) window.__wireValidate.init(document); } catch (e) {}
-    try { if (window.wireTheme) window.wireTheme.bind(document); } catch (e) {}
+  /**
+   * Run explicit component cleanup before removing the existing page.
+   *
+   * The reactive runtime also observes removed DOM nodes, but explicit
+   * disposal here guarantees that unmount hooks run before replacement.
+   */
+  function dispose(root) {
+    try {
+      if (
+        typeof window.__wrnexusDisposeBehaviors ===
+        "function"
+      ) {
+        window.__wrnexusDisposeBehaviors(root);
+      }
+    } catch (error) {
+      console.error(
+        "[wrnexus] failed to dispose page behaviors",
+        error,
+      );
+    }
+  }
+
+  /**
+   * Re-hydrate already-loaded runtimes against newly inserted DOM.
+   *
+   * All framework hydration functions must remain idempotent.
+   */
+  function rehydrate(root) {
+    try {
+      if (
+        typeof window.__wrnexusHydrateScopes ===
+        "function"
+      ) {
+        window.__wrnexusHydrateScopes(root);
+      }
+    } catch (error) {
+      console.error(
+        "[wrnexus] failed to hydrate reactive scopes",
+        error,
+      );
+    }
+
+    try {
+      if (
+        typeof window.__wrnexusHydrateCsrFetches ===
+        "function"
+      ) {
+        window.__wrnexusHydrateCsrFetches(root);
+      }
+    } catch (error) {
+      console.error(
+        "[wrnexus] failed to hydrate CSR bindings",
+        error,
+      );
+    }
+
+    try {
+      if (
+        window.__wireValidate &&
+        typeof window.__wireValidate.init ===
+          "function"
+      ) {
+        window.__wireValidate.init(document);
+      }
+    } catch (error) {
+      console.error(
+        "[wrnexus] failed to hydrate validation",
+        error,
+      );
+    }
+
+    try {
+      if (
+        window.wireTheme &&
+        typeof window.wireTheme.bind ===
+          "function"
+      ) {
+        window.wireTheme.bind(document);
+      }
+    } catch (error) {
+      console.error(
+        "[wrnexus] failed to hydrate theme bindings",
+        error,
+      );
+    }
+  }
+
+  function dispatchNavigationEvent(url) {
+    try {
+      window.dispatchEvent(
+        new CustomEvent("wrnexus:navigated", {
+          detail: {
+            url: url,
+          },
+        }),
+      );
+    } catch (_) {
+      // CustomEvent may not be available in very old browsers.
+    }
+  }
+
+  function hardNavigate(url) {
+    location.href = url;
   }
 
   function render(html, url, isPop) {
-    var doc = new DOMParser().parseFromString(html, "text/html");
-    var to = doc.getElementById(APP_ID);
-    var from = document.getElementById(APP_ID);
-    if (!to || !from) { location.href = url; return; } // structure mismatch → hard nav
-    if (doc.title) document.title = doc.title;
-    // Swap #app by importing nodes — NOT innerHTML — so it works under a strict
-    // Trusted-Types CSP (require-trusted-types-for 'script').
-    var imported = [];
-    for (var i = 0; i < to.childNodes.length; i++) imported.push(document.importNode(to.childNodes[i], true));
-    from.replaceChildren.apply(from, imported);
-    ensureScripts(doc);
-    rehydrate();
-    if (!isPop) { history.pushState({ wrnexusNav: true }, "", url); window.scrollTo(0, 0); }
-    try {
-      window.dispatchEvent(new CustomEvent("wrnexus:navigated", { detail: { url: url } }));
-    } catch (e) {}
-  }
+    var doc;
 
-  var inFlight = null;
+    try {
+      doc = new DOMParser().parseFromString(
+        html,
+        "text/html",
+      );
+    } catch (_) {
+      hardNavigate(url);
+      return;
+    }
+
+    var incomingApp =
+      doc.getElementById(APP_ID);
+
+    var currentApp =
+      document.getElementById(APP_ID);
+
+    if (!incomingApp || !currentApp) {
+      hardNavigate(url);
+      return;
+    }
+
+    if (doc.title) {
+      document.title = doc.title;
+    }
+
+    var importedNodes = [];
+
+    for (
+      var index = 0;
+      index < incomingApp.childNodes.length;
+      index++
+    ) {
+      importedNodes.push(
+        document.importNode(
+          incomingApp.childNodes[index],
+          true,
+        ),
+      );
+    }
+
+    /*
+     * Run unmount hooks and watcher cleanup while the current DOM is still
+     * connected. This is important for components that remove window or
+     * document listeners during lifecycle.unmount.
+     */
+    dispose(currentApp);
+
+    try {
+      /*
+       * Avoid innerHTML so navigation works with strict Trusted Types and CSP
+       * configurations.
+       */
+      currentApp.replaceChildren.apply(
+        currentApp,
+        importedNodes,
+      );
+    } catch (_) {
+      hardNavigate(url);
+      return;
+    }
+
+    /*
+     * Load any runtime required only by the incoming page. Fresh scripts
+     * initialise themselves when loaded.
+     */
+    ensureScripts(doc);
+
+    /*
+     * Hydrate runtimes that are already available. Hydration is scoped to
+     * #app instead of the entire document for less DOM traversal.
+     */
+    rehydrate(currentApp);
+
+    if (!isPop) {
+      history.pushState(
+        {
+          wrnexusNav: true,
+        },
+        "",
+        url,
+      );
+
+      window.scrollTo(0, 0);
+    }
+
+    dispatchNavigationEvent(url);
+  }
 
   function navigate(url, isPop) {
     var token = {};
+
     inFlight = token;
-    fetch(url, { headers: { "x-wrnexus-nav": "1", accept: "text/html" }, credentials: "same-origin" })
-      .then(function (r) {
-        if (inFlight !== token) return null; // superseded by a newer navigation
-        if (r.redirected && r.url) url = r.url; // follow server redirects (e.g. auth)
-        var ct = r.headers.get("content-type") || "";
-        if (ct.indexOf("text/html") === -1) { location.href = url; return null; }
-        return r.text().then(function (t) {
-          if (inFlight === token) render(t, url, isPop);
+
+    fetch(url, {
+      headers: {
+        "x-wrnexus-nav": "1",
+        accept: "text/html",
+      },
+
+      credentials: "same-origin",
+    })
+      .then(function (response) {
+        if (inFlight !== token) {
+          return null;
+        }
+
+        if (response.redirected && response.url) {
+          url = response.url;
+        }
+
+        var contentType =
+          response.headers.get("content-type") ||
+          "";
+
+        if (
+          contentType.indexOf("text/html") === -1
+        ) {
+          hardNavigate(url);
+          return null;
+        }
+
+        var contentType =
+          response.headers.get("content-type") ||
+          "";
+
+        if (
+          contentType.indexOf("text/html") === -1
+        ) {
+          hardNavigate(url);
+          return null;
+        }
+
+        return response.text().then(function (text) {
+          if (inFlight !== token) {
+            return;
+          }
+
+          render(text, url, isPop);
         });
       })
-      .catch(function () { location.href = url; });
+      .catch(function () {
+        if (inFlight === token) {
+          hardNavigate(url);
+        }
+      });
   }
 
   document.addEventListener(
     "click",
-    function (e) {
-      if (e.defaultPrevented || e.button !== 0 || e.metaKey || e.ctrlKey || e.shiftKey || e.altKey) return;
-      var a = e.target && e.target.closest ? e.target.closest("a") : null;
-      if (!isLocalLink(a)) return;
-      if (a.href === location.href) { e.preventDefault(); return; }
-      e.preventDefault();
-      navigate(a.href, false);
+    function (event) {
+      if (
+        event.defaultPrevented ||
+        event.button !== 0 ||
+        event.metaKey ||
+        event.ctrlKey ||
+        event.shiftKey ||
+        event.altKey
+      ) {
+        return;
+      }
+
+      var anchor =
+        event.target &&
+        event.target.closest
+          ? event.target.closest("a")
+          : null;
+
+      if (!isLocalLink(anchor)) {
+        return;
+      }
+
+      if (anchor.href === location.href) {
+        event.preventDefault();
+        return;
+      }
+
+      event.preventDefault();
+
+      navigate(anchor.href, false);
     },
     false,
   );
 
-  window.addEventListener("popstate", function () {
-    navigate(location.href, true);
-  });
+  window.addEventListener(
+    "popstate",
+    function () {
+      navigate(location.href, true);
+    },
+  );
 
-  // Programmatic navigation for forms/actions and app code.
+  /**
+   * Programmatic navigation for forms, actions and application code.
+   */
   window.__wrnexusNavigate = function (url) {
-    navigate(new URL(url, location.href).href, false);
+    navigate(
+      new URL(url, location.href).href,
+      false,
+    );
   };
 })();
 `.trim();
diff --git a/packages/csr/src/reactive-runtime.ts b/packages/csr/src/reactive-runtime.ts
index 21819861..872e47de 100644
--- a/packages/csr/src/reactive-runtime.ts
+++ b/packages/csr/src/reactive-runtime.ts
@@ -15,8 +15,109 @@
  * Expressions are evaluated by a tiny parser instead of `eval`/`new Function`,
  * so production can use a strong CSP without `unsafe-eval`.
  */
+
 export const REACTIVE_RUNTIME = String.raw`
 (function () {
+  var behaviorInstances = new WeakMap();
+  var mountedBehaviorRoots = new Set();
+  var pendingUpdateHooks = new Map();
+  var updateHooksScheduled = false;
+  var behaviorObserver;
+
+  function scheduleUpdateHook(element, callback) {
+    pendingUpdateHooks.set(element, callback);
+    if (updateHooksScheduled) return;
+    updateHooksScheduled = true;
+    queueMicrotask(function () {
+      updateHooksScheduled = false;
+      var pending = Array.from(pendingUpdateHooks.entries());
+      pendingUpdateHooks.clear();
+      pending.forEach(function (entry) {
+        var root = entry[0];
+        var hook = entry[1];
+        if (!root.isConnected) return;
+        try { hook(); } catch (error) {
+          console.error("[wrnexus] component update hook failed", error);
+        }
+      });
+    });
+  }
+
+  function parseBehavior(element) {
+    var raw = element.getAttribute("data-wrn-behavior");
+    if (!raw) return null;
+    try {
+      var parsed = JSON.parse(raw);
+      return parsed && typeof parsed === "object" ? parsed : null;
+    } catch (error) {
+      console.error("[wrnexus] failed to parse component behavior", error);
+      return null;
+    }
+  }
+
+  function extractBehaviorFunctions(source) {
+    var functions = [];
+    var re = /(?:async\s+)?function\s+([A-Za-z_$][\w$]*)\s*\(([^)]*)\)\s*\{/g;
+    var match;
+    while ((match = re.exec(source || ""))) {
+      var start = re.lastIndex;
+      var depth = 1;
+      var quote = "";
+      var i = start;
+      for (; i < source.length; i++) {
+        var ch = source[i];
+        if (quote) {
+          if (ch === "\\") i++;
+          else if (ch === quote) quote = "";
+          continue;
+        }
+        if (ch === '"' || ch === "'" || ch === "\`") {
+          quote = ch;
+          continue;
+        }
+        if (ch === "{") depth++;
+        else if (ch === "}" && --depth === 0) break;
+      }
+      if (depth !== 0) break;
+      functions.push({
+        name: match[1],
+        args: match[2].split(",").map(function (arg) { return arg.trim(); }).filter(Boolean),
+        body: source.slice(start, i),
+      });
+      re.lastIndex = i + 1;
+    }
+    return functions;
+  }
+
+  function splitStatements(input) {
+    var parts = [];
+    var start = 0;
+    var depth = 0;
+    var quote = "";
+    for (var i = 0; i < input.length; i++) {
+      var ch = input[i];
+      if (quote) {
+        if (ch === "\\") i++;
+        else if (ch === quote) quote = "";
+        continue;
+      }
+      if (ch === '"' || ch === "'" || ch === "\`") {
+        quote = ch;
+        continue;
+      }
+      if (ch === "(" || ch === "[" || ch === "{") depth++;
+      else if (ch === ")" || ch === "]" || ch === "}") depth--;
+      else if ((ch === ";" || ch === "\n" || ch === "\r") && depth === 0) {
+        var part = input.slice(start, i).trim();
+        if (part) parts.push(part);
+        start = i + 1;
+      }
+    }
+    var tail = input.slice(start).trim();
+    if (tail) parts.push(tail);
+    return parts;
+  }
+
   function signal(initial) {
     var value = initial;
     var subs = new Set();
@@ -24,8 +125,9 @@ export const REACTIVE_RUNTIME = String.raw`
       get: function () { return value; },
       set: function (v) {
         if (Object.is(v, value)) return;
+        var previous = value;
         value = v;
-        subs.forEach(function (f) { f(value); });
+        subs.forEach(function (f) { f(value, previous); });
       },
       subscribe: function (f) { subs.add(f); return function () { subs.delete(f); }; }
     };
@@ -58,29 +160,117 @@ export const REACTIVE_RUNTIME = String.raw`
     }
     function renderAll() { renderers.forEach(function (f) { f(); }); }
 
-    function readScope(name) {
-      var sig = signals[name];
-      if (!sig) return undefined;
-      if (currentRenderer) sig.subscribe(currentRenderer); // track dependency
-      return sig.get();
-    }
-    function peekScope(name) {
-      return signals[name] ? signals[name].get() : undefined;
+    var behaviorFunctions = {};
+    var stateWatchers = {};
+    var anyStateListeners = new Set();
+    var cleanupCallbacks = [];
+    var disposed = false;
+
+    function readGlobal(name) {
+      if (name === "window") return window;
+      if (name === "document") return document;
+      if (name === "console") return console;
+      if (name === "Math") return Math;
+      if (name === "JSON") return JSON;
+      if (name === "Date") return Date;
+      if (name === "URL") return URL;
+      if (name === "location") return window.location;
+      if (name === "history") return window.history;
+      if (name === "navigator") return window.navigator;
+      if (name === "setTimeout") return window.setTimeout.bind(window);
+      if (name === "clearTimeout") return window.clearTimeout.bind(window);
+      if (name === "requestAnimationFrame") return window.requestAnimationFrame.bind(window);
+      if (name === "cancelAnimationFrame") return window.cancelAnimationFrame.bind(window);
+      return undefined;
     }
 
-    function evalExpr(expr) {
-      return evaluateExpression(expr, readScope);
+    function readScope(name) {
+      var sig = signals[name];
+      if (sig) {
+        if (currentRenderer) sig.subscribe(currentRenderer);
+        return sig.get();
+      }
+      if (Object.prototype.hasOwnProperty.call(behaviorFunctions, name)) {
+        return behaviorFunctions[name];
+      }
+      return readGlobal(name);
     }
-    function runStmt(stmt) {
-      splitTopLevel(stmt, ";").forEach(function (part) {
-        runStatement(part, function (e) { return evaluateExpression(e, peekScope); }, peekScope, function (name, value) {
-          if (!signals[name]) {
-            signals[name] = signal(value);
-            renderAll(); // new variable: re-run once so readers pick it up + re-track
-          } else {
-            signals[name].set(value);
+
+    function peekScope(name) {
+      if (signals[name]) return signals[name].get();
+      if (Object.prototype.hasOwnProperty.call(behaviorFunctions, name)) {
+        return behaviorFunctions[name];
+      }
+      return readGlobal(name);
+    }
+
+    function notifyState(name, value, previous) {
+      var watchers = stateWatchers[name];
+      if (watchers) {
+        watchers.slice().forEach(function (watcher) {
+          try { watcher(value, previous); } catch (error) {
+            console.error("[wrnexus] watcher for '" + name + "' failed", error);
           }
         });
+      }
+      anyStateListeners.forEach(function (listener) {
+        try { listener(name, value, previous); } catch (error) {
+          console.error("[wrnexus] state subscriber failed", error);
+        }
+      });
+    }
+
+    function writeScope(name, value) {
+      if (!signals[name]) {
+        signals[name] = signal(value);
+        renderAll();
+        notifyState(name, value, undefined);
+        return;
+      }
+      var previous = signals[name].get();
+      if (Object.is(previous, value)) return;
+      signals[name].set(value);
+      notifyState(name, value, previous);
+    }
+
+    function evalExpr(expr, locals) {
+      return evaluateExpression(expr, function (name) {
+        if (locals && Object.prototype.hasOwnProperty.call(locals, name)) {
+          return locals[name];
+        }
+        return readScope(name);
+      });
+    }
+
+    function runStmt(stmt, locals) {
+      splitStatements(stmt).forEach(function (part) {
+        runStatement(
+          part,
+          function (expression) { return evalExpr(expression, locals); },
+          function (name) {
+            if (locals && Object.prototype.hasOwnProperty.call(locals, name)) return locals[name];
+            return peekScope(name);
+          },
+          function (name, value) {
+            if (locals && Object.prototype.hasOwnProperty.call(locals, name)) {
+              locals[name] = value;
+            } else {
+              writeScope(name, value);
+            }
+          },
+        );
+      });
+    }
+
+    function installBehaviorFunctions(source) {
+      extractBehaviorFunctions(source || "").forEach(function (definition) {
+        behaviorFunctions[definition.name] = function () {
+          var locals = {};
+          for (var i = 0; i < definition.args.length; i++) {
+            locals[definition.args[i]] = arguments[i];
+          }
+          runStmt(definition.body, locals);
+        };
       });
     }
 
@@ -287,27 +477,146 @@ export const REACTIVE_RUNTIME = String.raw`
       })(textNode, template);
     }
 
-    // data-on-<event> handlers, on the scope element and the descendants it owns.
+    // Event handlers on elements, window, and document.
     var nodes = [el].concat(Array.prototype.slice.call(el.querySelectorAll("*")));
     nodes.forEach(function (node) {
       if (!owns(node)) return;
       Array.prototype.slice.call(node.attributes).forEach(function (attr) {
         if (attr.name.indexOf("data-on-") !== 0) return;
-        var evt = attr.name.slice("data-on-".length);
+
+        var rawName = attr.name.slice("data-on-".length);
+        var target = node;
+        var evt = rawName;
+
+        if (rawName.indexOf("window-") === 0) {
+          target = window;
+          evt = rawName.slice("window-".length);
+        } else if (rawName.indexOf("document-") === 0) {
+          target = document;
+          evt = rawName.slice("document-".length);
+        }
+
         var stmt = attr.value;
-        node.addEventListener(evt, function () {
-          try { runStmt(stmt); } catch (e) {
-            console.error("[wrnexus] handler error in '" + stmt + "'", e);
+        var listener = function (event) {
+          try { runStmt(stmt, { event: event, $event: event }); } catch (error) {
+            console.error("[wrnexus] handler error in '" + stmt + "'", error);
           }
+        };
+
+        var options =
+          target === window && (evt === "scroll" || evt === "touchstart" || evt === "touchmove")
+            ? { passive: true }
+            : undefined;
+
+        target.addEventListener(evt, listener, options);
+        cleanupCallbacks.push(function () {
+          target.removeEventListener(evt, listener, options);
         });
       });
     });
 
+    var behavior = parseBehavior(el);
+    if (behavior) {
+      installBehaviorFunctions(behavior.functions);
+
+      (behavior.watches || []).forEach(function (watch) {
+        if (!watch || typeof watch.state !== "string" || typeof watch.body !== "string") return;
+        if (!stateWatchers[watch.state]) stateWatchers[watch.state] = [];
+        stateWatchers[watch.state].push(function (value, previous) {
+          runStmt(watch.body, { value: value, previous: previous });
+        });
+      });
+
+      var updateSource =
+        behavior.lifecycle && typeof behavior.lifecycle.update === "string"
+          ? behavior.lifecycle.update.trim()
+          : "";
+
+      if (updateSource) {
+        anyStateListeners.add(function () {
+          scheduleUpdateHook(el, function () {
+            if (!disposed) runStmt(updateSource);
+          });
+        });
+      }
+
+      var mountSource =
+        behavior.lifecycle && typeof behavior.lifecycle.mount === "string"
+          ? behavior.lifecycle.mount.trim()
+          : "";
+
+      var unmountSource =
+        behavior.lifecycle && typeof behavior.lifecycle.unmount === "string"
+          ? behavior.lifecycle.unmount.trim()
+          : "";
+
+      var instance = {
+        dispose: function () {
+          if (disposed) return;
+          disposed = true;
+          cleanupCallbacks.splice(0).reverse().forEach(function (cleanup) {
+            try { cleanup(); } catch (_) { /* ignore cleanup errors */ }
+          });
+          pendingUpdateHooks.delete(el);
+          if (unmountSource) {
+            try { runStmt(unmountSource); } catch (error) {
+              console.error("[wrnexus] component unmount hook failed", error);
+            }
+          }
+          mountedBehaviorRoots.delete(el);
+          behaviorInstances.delete(el);
+          el.__wrnexusScope = false;
+        },
+      };
+
+      behaviorInstances.set(el, instance);
+      mountedBehaviorRoots.add(el);
+
+      if (mountSource) {
+        queueMicrotask(function () {
+          if (!disposed && el.isConnected) {
+            try { runStmt(mountSource); } catch (error) {
+              console.error("[wrnexus] component mount hook failed", error);
+            }
+          }
+        });
+      }
+    }
+
     renderAll();
   }
 
+  function disposeBehaviors(root) {
+    var elements = [];
+    if (root && root.nodeType === 1 && root.hasAttribute("data-wrn-behavior")) {
+      elements.push(root);
+    }
+    if (root && root.querySelectorAll) {
+      Array.prototype.push.apply(elements, root.querySelectorAll("[data-wrn-behavior]"));
+    }
+    elements.reverse().forEach(function (element) {
+      var instance = behaviorInstances.get(element);
+      if (instance) instance.dispose();
+    });
+  }
+
+  function ensureBehaviorObserver() {
+    if (behaviorObserver || typeof MutationObserver === "undefined") return;
+    behaviorObserver = new MutationObserver(function (records) {
+      records.forEach(function (record) {
+        Array.prototype.forEach.call(record.removedNodes, function (node) {
+          if (node && node.nodeType === 1) disposeBehaviors(node);
+        });
+      });
+    });
+    behaviorObserver.observe(document.documentElement, { childList: true, subtree: true });
+  }
+
   function hydrateScopes(root) {
-    (root || document).querySelectorAll("[data-scope]").forEach(setupScope);
+    var host = root || document;
+    if (host.nodeType === 1 && host.matches && host.matches("[data-scope]")) setupScope(host);
+    if (host.querySelectorAll) host.querySelectorAll("[data-scope]").forEach(setupScope);
+    ensureBehaviorObserver();
   }
 
   function parseScopeDecl(decl) {
@@ -635,6 +944,7 @@ export const REACTIVE_RUNTIME = String.raw`
 
   window.__wrnexusHydrateScopes = hydrateScopes;
   window.__wrnexusHydrateCsrFetches = hydrateCsrFetches;
+  window.__wrnexusDisposeBehaviors = disposeBehaviors;
   if (document.readyState === "loading") {
     document.addEventListener("DOMContentLoaded", function () {
       hydrateScopes(document);
diff --git a/packages/db/package.json b/packages/db/package.json
index 7f56db4d..5f7945ef 100644
--- a/packages/db/package.json
+++ b/packages/db/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/db",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",
diff --git a/packages/dev-server/package.json b/packages/dev-server/package.json
index 2567c2dd..3079b3c3 100644
--- a/packages/dev-server/package.json
+++ b/packages/dev-server/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/dev-server",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
diff --git a/packages/encryption/package.json b/packages/encryption/package.json
index 1a49e1b4..277e1ca2 100644
--- a/packages/encryption/package.json
+++ b/packages/encryption/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/encryption",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",
diff --git a/packages/helpers/package.json b/packages/helpers/package.json
index 81581c21..1be148c7 100644
--- a/packages/helpers/package.json
+++ b/packages/helpers/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/helpers",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "description": "Safe convenience helpers for WrNexus request contexts and common application flows.",
diff --git a/packages/i18n/package.json b/packages/i18n/package.json
index e67e265f..96e2d25a 100644
--- a/packages/i18n/package.json
+++ b/packages/i18n/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/i18n",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",
diff --git a/packages/jwt/package.json b/packages/jwt/package.json
index 14c14e12..c9976710 100644
--- a/packages/jwt/package.json
+++ b/packages/jwt/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/jwt",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",
diff --git a/packages/mobile/package.json b/packages/mobile/package.json
index 070b1393..5987d781 100644
--- a/packages/mobile/package.json
+++ b/packages/mobile/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/mobile",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
diff --git a/packages/native/package.json b/packages/native/package.json
index 9e435999..e94dc4e2 100644
--- a/packages/native/package.json
+++ b/packages/native/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/native",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
diff --git a/packages/oauth/package.json b/packages/oauth/package.json
index fd5b398c..5246c971 100644
--- a/packages/oauth/package.json
+++ b/packages/oauth/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/oauth",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",
diff --git a/packages/pubsub/package.json b/packages/pubsub/package.json
index 8507e3d9..2666ed0e 100644
--- a/packages/pubsub/package.json
+++ b/packages/pubsub/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/pubsub",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",
diff --git a/packages/queue/package.json b/packages/queue/package.json
index 10b9f720..e1f30a7e 100644
--- a/packages/queue/package.json
+++ b/packages/queue/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/queue",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",
diff --git a/packages/reactive/package.json b/packages/reactive/package.json
index 60f691e5..80fbc1fb 100644
--- a/packages/reactive/package.json
+++ b/packages/reactive/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/reactive",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
diff --git a/packages/router/package.json b/packages/router/package.json
index 667d1ef1..cd0c372b 100644
--- a/packages/router/package.json
+++ b/packages/router/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/router",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
diff --git a/packages/ssr/package.json b/packages/ssr/package.json
index 771701ff..84293f68 100644
--- a/packages/ssr/package.json
+++ b/packages/ssr/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/ssr",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
diff --git a/packages/styles/package.json b/packages/styles/package.json
index 24edc9ed..b7b8059d 100644
--- a/packages/styles/package.json
+++ b/packages/styles/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/styles",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "type": "module",
   "main": "src/index.ts",
   "exports": {
diff --git a/packages/test/package.json b/packages/test/package.json
index f09f56c6..08b19609 100644
--- a/packages/test/package.json
+++ b/packages/test/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/test",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",
diff --git a/packages/tracking/package.json b/packages/tracking/package.json
index 652c4c22..4ec18f8b 100644
--- a/packages/tracking/package.json
+++ b/packages/tracking/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/tracking",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",
diff --git a/packages/ui/package.json b/packages/ui/package.json
index 259cf88e..30706e92 100644
--- a/packages/ui/package.json
+++ b/packages/ui/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/ui",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",
diff --git a/packages/uploader/package.json b/packages/uploader/package.json
index 2bd8204e..7ed7f3e4 100644
--- a/packages/uploader/package.json
+++ b/packages/uploader/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/uploader",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",
diff --git a/packages/validation/package.json b/packages/validation/package.json
index eda60bb4..b713242c 100644
--- a/packages/validation/package.json
+++ b/packages/validation/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/validation",
-  "version": "0.2.30",
+  "version": "0.2.31",
   "private": true,
   "type": "module",
   "main": "src/index.ts",