diff --git a/ui/sources/services/core.js b/ui/sources/services/core.js
index aa0b4c7..af4360f 100644
--- a/ui/sources/services/core.js
+++ b/ui/sources/services/core.js
@@ -34,6 +34,9 @@ export default class Core {
 	/** @type {Graphics} */
 	#graphics = null;
 
+	/** @type {(variables: Variable[]) => void} */
+	#on_variables = null;
+
 	/**
 	 * @param {string} name
 	 * @param {WebAssembly.Memory} memory
@@ -55,23 +58,17 @@ export default class Core {
 		Core.#running = new Promise(resolve => Core.#stop = resolve);
 
 		this.#graphics = new Graphics(canvas);
+		this.#on_variables = on_variables
 
 		const origin = location.origin + location.pathname.substring(0, location.pathname.lastIndexOf('/'));
 		const config = { core: this.#name, system, rom, origin, memory: this.#memory };
 		const script = await (await fetch('worker.js')).text();
 
 		const handler = async message => {
-			switch (message.data.type) {
-				case 'thread':
-					const thread = new Parallel(Interop, false, handler);
-					const core = await thread.create(this.#name, script);
-					await core.init(Parallel.instrument(this), await Files.clone(), { ...config, ...message.data });
-					this.#threads.push(thread);
-					break;
-				case 'variables':
-					on_variables(message.data.variables);
-					break;
-			}
+			const thread = new Parallel(Interop, false, handler);
+			const core = await thread.create(this.#name, script);
+			await core.init(Parallel.instrument(this), await Files.clone(), { ...config, ...message.data });
+			this.#threads.push(thread);
 		}
 
 		this.#parallel = new Parallel(Interop, false, handler);
@@ -126,13 +123,21 @@ export default class Core {
 
 	/**
 	 * @param {Audio} audio
-	 * @returns
+	 * @returns {void}
 	 */
 	play(audio) {
 		const audio_view = new Float32Array(this.#memory.buffer, audio.data, audio.frames * 2);
 		AudioPlayer.queue(audio_view.slice(), audio.rate);
 	}
 
+	/**
+	 * @param {Variable[]} variables
+	 * @returns {void}
+	 */
+	variables(variables) {
+		this.#on_variables(variables);
+	}
+
 	/** @param {Settings} settings @returns {Promise<void>} */
 	async settings(settings) { await this.#interop?.variables(settings.variables); }
 
diff --git a/ui/sources/services/interop.js b/ui/sources/services/interop.js
index 4dbf9f1..2276d5b 100644
--- a/ui/sources/services/interop.js
+++ b/ui/sources/services/interop.js
@@ -127,23 +127,18 @@ export default class Interop {
 
 		const junie_interop_video = (video_c) => {
 			const video = Video.parse(config.memory, video_c);
-			if (!video.data)
-				return;
-
-			this.#core.draw(video);
+			if (video.data)
+				this.#core.draw(video);
 		};
 
 		const junie_interop_audio = (audio_c) => {
 			const audio = Audio.parse(config.memory, audio_c);
-			if (!audio.frames)
-				return;
-
-			this.#core.play(audio);
+			if (audio.frames)
+				this.#core.play(audio);
 		};
 
 		const junie_interop_variables = (variables_c) => {
-			const variables = Variable.parse(this.#instance, variables_c);
-			postMessage({ type: 'variables', variables });
+			this.#core.variables(Variable.parse(this.#instance, variables_c));
 		}
 
 		const source = await WebAssembly.instantiateStreaming(fetch(`${config.origin}/modules/${config.core}.wasm`), {
@@ -151,7 +146,7 @@ export default class Interop {
 			wasi_snapshot_preview1: this.#wasi.environment,
 			wasi: { 'thread-spawn': (start_arg) => {
 				const id = filesystem.id();
-				postMessage({ type: 'thread', id, fds: this.#wasi.fds, start_arg });
+				postMessage({ id, fds: this.#wasi.fds, start_arg });
 				return id;
 			}},
 		});