diff --git a/demo/audio-beats-with-event-propagators.html b/demo/audio-beats-with-event-propagators.html
index 7bd5d5c..6a19438 100644
--- a/demo/audio-beats-with-event-propagators.html
+++ b/demo/audio-beats-with-event-propagators.html
@@ -41,14 +41,14 @@
     <folk-event-propagator
       source="folk-metronome"
       target="#kick"
-      triggers="beat"
+      trigger="beat"
       expression="play(): from.beat === 1"
     ></folk-event-propagator>
 
     <folk-event-propagator
       source="folk-metronome"
       target="#hat"
-      triggers="beat"
+      trigger="beat"
       expression="play(): from.beat % 3"
     ></folk-event-propagator>
 
diff --git a/demo/embeddable-llm-with-propagators.html b/demo/embeddable-llm-with-propagators.html
index acc185c..349dadd 100644
--- a/demo/embeddable-llm-with-propagators.html
+++ b/demo/embeddable-llm-with-propagators.html
@@ -90,14 +90,14 @@
     <folk-event-propagator
       source="#recipe"
       target="folk-llm"
-      triggers="click"
+      trigger="click"
       expression="prompt: `double this list of ingredients '${from.innerHTML}'`"
     ></folk-event-propagator>
 
     <folk-event-propagator
       source="folk-llm"
       target="folk-timer"
-      triggers="started"
+      trigger="started"
       expression="reset(): true
 start(): true"
     >
@@ -106,7 +106,7 @@ start(): true"
     <folk-event-propagator
       source="folk-llm"
       target="folk-timer"
-      triggers="finished"
+      trigger="finished"
       expression="stop(): true"
     ></folk-event-propagator>
 
diff --git a/demo/event-propagators-with-weather.html b/demo/event-propagators-with-weather.html
index 243da72..9a337fa 100644
--- a/demo/event-propagators-with-weather.html
+++ b/demo/event-propagators-with-weather.html
@@ -39,7 +39,7 @@
     <folk-event-propagator
       source="#box1"
       target="#box2"
-      triggers="click"
+      trigger="click"
       expression="textContent: to.textContent + 'r'"
     ></folk-event-propagator>
 
@@ -48,13 +48,12 @@
     <folk-event-propagator
       source="#box3"
       target="#box4"
-      triggers="transform"
+      trigger="transform"
       expression="y: from.x, 
 rotation: from.x"
     ></folk-event-propagator>
 
     <script type="module">
-      import 'https://cdn.jsdelivr.net/npm/@zachleat/snow-fall';
       import '../src/standalone/folk-shape.ts';
       import '../src/standalone/folk-event-propagator.ts';
 
@@ -80,6 +79,8 @@ rotation: from.x"
         }
         isBlowing = !isBlowing;
       });
+
+      requestIdleCallback(() => import('https://cdn.jsdelivr.net/npm/@zachleat/snow-fall'));
     </script>
   </body>
 </html>
diff --git a/demo/event-propagators.html b/demo/event-propagators.html
index a3df733..0ddcde9 100644
--- a/demo/event-propagators.html
+++ b/demo/event-propagators.html
@@ -30,7 +30,7 @@
     <folk-event-propagator
       source="#box1"
       target="#box2"
-      triggers="click"
+      trigger="click"
       expression="textContent: to.textContent + '!'"
     ></folk-event-propagator>
 
@@ -39,7 +39,7 @@
     <folk-event-propagator
       source="#box3"
       target="#box4"
-      triggers="transform"
+      trigger="transform"
       expression="y: from.x, 
 rotation: from.x"
     ></folk-event-propagator>
diff --git a/demo/folk-interface-for-qr-codes.html b/demo/folk-interface-for-qr-codes.html
index 3274ec7..190714e 100644
--- a/demo/folk-interface-for-qr-codes.html
+++ b/demo/folk-interface-for-qr-codes.html
@@ -52,21 +52,21 @@
     <folk-event-propagator
       source="textarea"
       target="sl-qr-code"
-      triggers="input"
+      trigger="input"
       expression="value: from.value"
     ></folk-event-propagator>
 
     <folk-event-propagator
       source="input[type='range']"
       target="sl-qr-code"
-      triggers="input"
+      trigger="input"
       expression="radius: from.value"
     ></folk-event-propagator>
 
     <folk-event-propagator
       source="input[type='color']"
       target="sl-qr-code"
-      triggers="input"
+      trigger="input"
       expression="fill: from.value"
     ></folk-event-propagator>
 
diff --git a/demo/proximity-based-communication-and-event-propagators.html b/demo/proximity-based-communication-and-event-propagators.html
index 2afe62b..028170f 100644
--- a/demo/proximity-based-communication-and-event-propagators.html
+++ b/demo/proximity-based-communication-and-event-propagators.html
@@ -76,14 +76,14 @@
     <folk-event-propagator
       source="input[type='range']"
       target="folk-map"
-      triggers="input"
+      trigger="input"
       expression="lat: from.value"
     ></folk-event-propagator>
 
     <folk-event-propagator
       source="folk-map"
       target="input[type='range']"
-      triggers="recenter"
+      trigger="recenter"
       expression="value: from.lat"
     ></folk-event-propagator>
 
diff --git a/demo/spreadsheet-map-propagator.html b/demo/spreadsheet-map-propagator.html
index d9aa4f5..99e57e0 100644
--- a/demo/spreadsheet-map-propagator.html
+++ b/demo/spreadsheet-map-propagator.html
@@ -143,21 +143,21 @@
     <folk-event-propagator
       source="#map1"
       target="folk-cell[column='A'][row='1']"
-      triggers="recenter"
+      trigger="recenter"
       expression="expression: from.coordinates.lat"
     ></folk-event-propagator>
 
     <folk-event-propagator
       source="#map1"
       target="folk-cell[column='A'][row='2']"
-      triggers="recenter"
+      trigger="recenter"
       expression="expression: from.coordinates.lng"
     ></folk-event-propagator>
 
     <folk-event-propagator
       source="folk-cell[column='A'][row='3']"
       target="#map2"
-      triggers="propagate"
+      trigger="propagate"
       expression="coordinates: from.value"
     ></folk-event-propagator>
 
diff --git a/src/folk-base-connection.ts b/src/folk-base-connection.ts
index dcc025c..3618005 100644
--- a/src/folk-base-connection.ts
+++ b/src/folk-base-connection.ts
@@ -10,11 +10,7 @@ const folkObserver = new FolkObserver();
 export class FolkBaseConnection extends FolkElement {
   @property({ type: String, reflect: true }) source = '';
 
-  #sourceElement: Element | null = null;
-
-  get sourceElement() {
-    return this.#sourceElement;
-  }
+  @state() sourceElement: Element | null = null;
 
   @state() sourceRect: DOMRectReadOnly | null = null;
 
@@ -22,11 +18,7 @@ export class FolkBaseConnection extends FolkElement {
 
   @state() targetRect: DOMRectReadOnly | null = null;
 
-  #targetElement: Element | null = null;
-
-  get targetElement() {
-    return this.#targetElement;
-  }
+  @state() targetElement: Element | null = null;
 
   override disconnectedCallback() {
     super.disconnectedCallback();
@@ -58,20 +50,20 @@ export class FolkBaseConnection extends FolkElement {
     if (vertex) {
       this.sourceRect = DOMRectReadOnly.fromRect(vertex);
     } else {
-      this.#sourceElement = document.querySelector(this.source);
+      this.sourceElement = document.querySelector(this.source);
 
-      if (this.#sourceElement === null) {
+      if (this.sourceElement === null) {
         this.sourceRect = null;
       } else {
-        folkObserver.observe(this.#sourceElement, this.#sourceCallback);
+        folkObserver.observe(this.sourceElement, this.#sourceCallback);
       }
     }
   }
 
   unobserveSource() {
-    if (this.#sourceElement === null) return;
+    if (this.sourceElement === null) return;
 
-    folkObserver.unobserve(this.#sourceElement, this.#sourceCallback);
+    folkObserver.unobserve(this.sourceElement, this.#sourceCallback);
   }
 
   #targetCallback = (entry: ClientRectObserverEntry) => {
@@ -86,18 +78,18 @@ export class FolkBaseConnection extends FolkElement {
     if (vertex) {
       this.targetRect = DOMRectReadOnly.fromRect(vertex);
     } else {
-      this.#targetElement = document.querySelector(this.target);
+      this.targetElement = document.querySelector(this.target);
 
-      if (this.#targetElement === null) {
+      if (this.targetElement === null) {
         this.targetRect = null;
       } else {
-        folkObserver.observe(this.#targetElement, this.#targetCallback);
+        folkObserver.observe(this.targetElement, this.#targetCallback);
       }
     }
   }
 
   unobserveTarget() {
-    if (this.#targetElement === null) return;
-    folkObserver.unobserve(this.#targetElement, this.#targetCallback);
+    if (this.targetElement === null) return;
+    folkObserver.unobserve(this.targetElement, this.#targetCallback);
   }
 }
diff --git a/src/folk-event-propagator.ts b/src/folk-event-propagator.ts
index 8f724b3..62ce5d1 100644
--- a/src/folk-event-propagator.ts
+++ b/src/folk-event-propagator.ts
@@ -1,5 +1,6 @@
 import { css, PropertyValues } from '@lit/reactive-element';
 import { FolkRope } from './folk-rope.ts';
+import { property } from '@lit/reactive-element/decorators.js';
 // import * as parser from '@babel/parser';
 
 export class FolkEventPropagator extends FolkRope {
@@ -30,30 +31,77 @@ export class FolkEventPropagator extends FolkRope {
     }
   `;
 
-  #triggers: string[] = [];
-  get triggers() {
-    return this.#triggers;
-  }
-  set triggers(triggers: string | string[]) {
-    if (typeof triggers === 'string') {
-      triggers = triggers.split(',');
-    }
-    this.#removeEventListenersToSource();
+  @property({ type: String, reflect: true }) trigger = '';
 
-    this.#triggers = triggers;
+  @property({ type: String, reflect: true }) expression = '';
 
-    this.#addEventListenersToSource();
-  }
-
-  #expression = '';
   #function: Function | null = null;
-  get expression() {
-    return this.#expression;
+  #triggerTextarea = document.createElement('textarea');
+  #expressionTextarea = document.createElement('textarea');
+
+  override firstUpdated(changedProperties: PropertyValues<this>): void {
+    super.firstUpdated(changedProperties);
+
+    this.#triggerTextarea.addEventListener('change', () => {
+      this.trigger = this.#triggerTextarea.value;
+    });
+
+    this.#expressionTextarea.addEventListener('input', () => {
+      this.expression = this.#expressionTextarea.value;
+    });
+
+    this.#triggerTextarea.value = this.trigger;
+
+    this.#expressionTextarea.value = this.expression;
+
+    this.renderRoot.append(this.#triggerTextarea, this.#expressionTextarea);
   }
-  set expression(expression) {
-    this.mend();
-    this.#expression = expression;
-    const processedExp = expression.trim();
+
+  override updated(changedProperties: PropertyValues<this>): void {
+    super.update(changedProperties);
+
+    if (changedProperties.has('trigger')) {
+      this.sourceElement?.removeEventListener(this.trigger, this.#evaluateExpression);
+      this.sourceElement?.addEventListener(this.trigger, this.#evaluateExpression);
+    }
+
+    if (changedProperties.has('expression')) {
+      this.#parseExpression();
+    }
+
+    const previousSourceElement = changedProperties.get('sourceElement');
+    if (previousSourceElement) {
+      const trigger = changedProperties.get('trigger') || this.trigger;
+      previousSourceElement.removeEventListener(trigger, this.#evaluateExpression);
+      this.sourceElement?.addEventListener(this.trigger, this.#evaluateExpression);
+    }
+  }
+
+  override disconnectedCallback(): void {
+    super.disconnectedCallback();
+    this.sourceElement?.removeEventListener(this.trigger, this.#evaluateExpression);
+  }
+
+  override draw() {
+    super.draw();
+
+    const triggerPoint = this.points[Math.floor(this.points.length / 5)];
+
+    if (triggerPoint) {
+      this.#triggerTextarea.style.left = `${triggerPoint.pos.x}px`;
+      this.#triggerTextarea.style.top = `${triggerPoint.pos.y}px`;
+    }
+
+    const expressionPoint = this.points[Math.floor(this.points.length / 2)];
+
+    if (expressionPoint) {
+      this.#expressionTextarea.style.left = `${expressionPoint.pos.x}px`;
+      this.#expressionTextarea.style.top = `${expressionPoint.pos.y}px`;
+    }
+  }
+
+  #parseExpression() {
+    const processedExp = this.expression.trim();
 
     const codeLines: string[] = [];
 
@@ -103,6 +151,7 @@ to.${key} = ${value};`);
     try {
       // parseAst(functionBody);
       this.#function = new Function('from', 'to', 'event', functionBody);
+      this.mend();
     } catch (error) {
       console.warn('Failed to parse expression:', error, functionBody);
       this.cut();
@@ -110,80 +159,8 @@ to.${key} = ${value};`);
     }
   }
 
-  #triggerTextarea = document.createElement('textarea');
-  #expressionTextarea = document.createElement('textarea');
-
-  override firstUpdated(changedProperties: PropertyValues<this>): void {
-    super.firstUpdated(changedProperties);
-
-    this.#triggerTextarea.addEventListener('change', () => {
-      this.triggers = this.#triggerTextarea.value;
-    });
-
-    this.triggers = this.#triggerTextarea.value = this.getAttribute('triggers') || '';
-
-    this.renderRoot.appendChild(this.#triggerTextarea);
-
-    this.#expressionTextarea.addEventListener('input', () => {
-      this.expression = this.#expressionTextarea.value;
-    });
-
-    this.renderRoot.appendChild(this.#expressionTextarea);
-
-    this.expression = this.#expressionTextarea.value = this.getAttribute('expression') || '';
-  }
-
-  override draw() {
-    super.draw();
-
-    const triggerPoint = this.points[Math.floor(this.points.length / 5)];
-
-    if (triggerPoint) {
-      this.#triggerTextarea.style.left = `${triggerPoint.pos.x}px`;
-      this.#triggerTextarea.style.top = `${triggerPoint.pos.y}px`;
-    }
-
-    const expressionPoint = this.points[Math.floor(this.points.length / 2)];
-
-    if (expressionPoint) {
-      this.#expressionTextarea.style.left = `${expressionPoint.pos.x}px`;
-      this.#expressionTextarea.style.top = `${expressionPoint.pos.y}px`;
-    }
-  }
-
-  override observeSource() {
-    super.observeSource();
-
-    this.#addEventListenersToSource();
-  }
-
-  #addEventListenersToSource() {
-    for (const trigger of this.#triggers) {
-      // TODO: add special triggers for intersection, rAF, etc.
-      this.sourceElement?.addEventListener(trigger, this.evaluateExpression);
-    }
-  }
-
-  override unobserveSource() {
-    super.unobserveSource();
-    this.#removeEventListenersToSource();
-  }
-
-  #removeEventListenersToSource() {
-    for (const trigger of this.#triggers) {
-      this.sourceElement?.removeEventListener(trigger, this.evaluateExpression);
-    }
-  }
-
-  override observeTarget() {
-    super.observeTarget();
-  }
-
-  override unobserveTarget() {
-    super.unobserveTarget();
-  }
-
-  evaluateExpression = (event?: Event) => {
+  #evaluateExpression = (event?: Event) => {
+    console.log('eval');
     if (this.sourceElement === null || this.targetElement === null) return;
     this.stroke = 'black';
     if (!this.#function) return;
diff --git a/src/folk-toolbar.ts b/src/folk-toolbar.ts
index 7db0a92..80a458b 100644
--- a/src/folk-toolbar.ts
+++ b/src/folk-toolbar.ts
@@ -106,7 +106,7 @@ export class FolkToolbar extends HTMLElement {
       <folk-event-propagator 
         source="#${sourceId}"
         target="#${targetId}"
-        triggers="click"
+        trigger="click"
         expression="rotation: Math.random() * 360"
       ></folk-event-propagator>
     `,