diff --git a/TODO b/TODO
index ff62f05..d8d645a 100644
--- a/TODO
+++ b/TODO
@@ -19,3 +19,5 @@
 * LV2 (and raw midi): uneven midi pitch bend, what to do?
 * VST3: noteOn, noteOff tuning, what to do? (https://steinbergmedia.github.io/vst3_doc/vstinterfaces/structSteinberg_1_1Vst_1_1NoteOnEvent.html, https://steinbergmedia.github.io/vst3_doc/vstinterfaces/structSteinberg_1_1Vst_1_1NoteOffEvent.html)
 * midi out
+* vst3 tail, web process return true/false
+* error checking etc. web, especially processor.js
diff --git a/templates/web-make/Makefile b/templates/web-make/Makefile
index 813009e..c918f25 100644
--- a/templates/web-make/Makefile
+++ b/templates/web-make/Makefile
@@ -8,20 +8,23 @@ LDFLAGS = \
 	-Wl,--lto-O3 \
 	-Wl,-strip-all \
 	-Wl,--export-table \
-	-Wl,--export=wrapper_new \
-	-Wl,--export=wrapper_free \
-	-Wl,--export=wrapper_get_ins \
-	-Wl,--export=wrapper_get_outs \
-	-Wl,--export=wrapper_get_param_values \
-	-Wl,--export=wrapper_process \
-	-Wl,--export=wrapper_set_parameter \
+	-Wl,--export=processor_new \
+	-Wl,--export=processor_free \
+	-Wl,--export=processor_get_ins \
+	-Wl,--export=processor_get_outs \
+	-Wl,--export=processor_get_param_values \
+	-Wl,--export=processor_process \
+	-Wl,--export=processor_set_parameter \
 	-Wl,-z,stack-size=$$((8*1024*1024)) \
 	-nostdlib
 
-all: build/${BUNDLE_NAME}.wasm
+all: build/${BUNDLE_NAME}.wasm build/${BUNDLE_NAME}_processor.js
 
-build/${BUNDLE_NAME}.wasm: src/data.h src/memset.h src/plugin.h src/walloc.h src/wrapper.c | build
-	${CC} src/wrapper.c -o $@ ${CFLAGS} ${LDFLAGS} ${CFLAGS_EXTRA} ${LIBS_EXTRA}
+build/${BUNDLE_NAME}.wasm: src/data.h src/memset.h src/plugin.h src/walloc.h src/processor.c | build
+	${CC} src/processor.c -o $@ ${CFLAGS} ${LDFLAGS} ${CFLAGS_EXTRA} ${LIBS_EXTRA}
+
+build/${BUNDLE_NAME}_processor.js: src/processor.js | build
+	cp $^ $@
 
 build:
 	mkdir -p $@
diff --git a/templates/web/src/wrapper.c b/templates/web/src/processor.c
similarity index 86%
rename from templates/web/src/wrapper.c
rename to templates/web/src/processor.c
index 42934d3..67fa829 100644
--- a/templates/web/src/wrapper.c
+++ b/templates/web/src/processor.c
@@ -27,7 +27,7 @@ typedef struct {
 #endif
 } instance;
 
-instance * wrapper_new(float sample_rate) {
+instance * processor_new(float sample_rate) {
 	instance * i = malloc(sizeof(instance));
 	if (i == NULL)
 		return NULL;
@@ -66,32 +66,32 @@ instance * wrapper_new(float sample_rate) {
 	return i;
 }
 
-void wrapper_free(instance * i) {
+void processor_free(instance * i) {
 	plugin_fini(&i->p);
 	if (i->mem)
 		free(i->mem);
 	free(i);
 }
 
-float * wrapper_get_x_buf(instance * i) {
+float * processor_get_x_buf(instance * i) {
 #if DATA_PRODUCT_AUDIO_INPUT_CHANNELS_N > 0
 	return i->x_buf;
 #else
-	(void *)i;
+	(void)i;
 	return NULL;
 #endif
 }
 
-float * wrapper_get_y_buf(instance * i) {
+float * processor_get_y_buf(instance * i) {
 #if DATA_PRODUCT_AUDIO_INPUT_CHANNELS_N > 0
 	return i->y_buf;
 #else
-	(void *)i;
+	(void)i;
 	return NULL;
 #endif
 }
 
-float * wrapper_get_out_params(instance *i) {
+float * processor_get_out_params(instance *i) {
 #if DATA_PRODUCT_PARAMETERS_OUTPUT_N > 0
 	return i->out_params;
 #else
@@ -100,11 +100,11 @@ float * wrapper_get_out_params(instance *i) {
 #endif
 }
 
-void wrapper_set_parameter(instance *i, int32_t index, float value) {
+void processor_set_parameter(instance *i, int32_t index, float value) {
 	plugin_set_parameter(&i->p, index, value);
 }
 
-void wrapper_process(instance *i, int32_t n_samples) {
+void processor_process(instance *i, int32_t n_samples) {
 #if DATA_PRODUCT_AUDIO_INPUT_CHANNELS_N > 0
 	const float **x = i->x;
 #else
diff --git a/templates/web/src/processor.js b/templates/web/src/processor.js
new file mode 100644
index 0000000..0e36b5a
--- /dev/null
+++ b/templates/web/src/processor.js
@@ -0,0 +1,135 @@
+/* 
+ * Copyright (C) 2022, 2024 Orastron Srl unipersonale
+ */
+
+var buses = {{=JSON.stringify(it.product.buses, null, 2)}};
+var parameters = {{=JSON.stringify(it.product.parameters, null, 2)}};
+
+class Processor extends AudioWorkletProcessor {
+	throwError(msg) {
+		this.port.postMessage({ type: "error", msg: msg);
+		throw msg;
+	}
+
+	constructor(options) {
+		super();
+
+		var module = new WebAssembly.Module(options.processorOptions.wasmBytes);
+		var instance = new WebAssembly.Instance(module, { env: {} });
+		this.module = instance.exports;
+
+		this.instance = this.module.processor_new(sampleRate);
+		if (!this.instance)
+			this.throwError("Could not instantiate processor module");
+
+		function getBuffers(p, output) {
+			var ret = [];
+			for (var i = 0; i < buses.length; i++) {
+				if ((output && buses[i].direction == "input") || (!output && buses[i].direction == "output"))
+					continue;
+				if (buses[i].channels == "mono") {
+					ret.push([ new Float32Array(this.module.memory.buffer, p, 128) ]);
+					p += 128 * 4;
+				} else {
+					ret.push([
+						new Float32Array(this.module.memory.buffer, p, 128),
+						new Float32Array(this.module.memory.buffer, p + 128 * 4, 128)
+					]);
+					p += 2 * 128 * 4;
+				}
+			}
+			return ret;
+		}
+		this.x = getBuffers.call(this, this.module.processor_get_x_buf(this.instance), false);
+		this.y = getBuffers.call(this, this.module.processor_get_y_buf(this.instance), true);
+
+		this.parametersIn = [];
+		for (var i = 0; i < parameters.length; i++)
+			if (parameters[i].direction == "input")
+				this.parametersIn.push({ index: i, value: NaN });
+
+		this.parametersOut = [];
+		for (var i = 0; i < parameters.length; i++)
+			if (parameters[i].direction == "output")
+				this.parametersOut.push({ index: i, value: NaN });
+
+		if (this.parametersOut.length > 0)
+			this.parametersOutValues = new Float32Array(this.module.memory.buffer, this.module.processor_get_out_params(this.instance), this.parametersOut.length);
+		
+		this.paramOutChangeMsg = { type: "paramOutChange", index: NaN, value: NaN };
+	}
+
+	process(input, outputs, params) {
+		for (var i = 0; i < this.parametersIn.length; i++) {
+			var index = this.parametersIn[i].index;
+			var parameter = parameters[index];
+			var name = parameter.name;
+			var value = params[p.name][0];
+			if (value != this.parametersIn[i].value) {
+				if (parameter.isBypass || parameter.toggled)
+					value = value > 0 ? 0 : 1;
+				else if (parameter.integer)
+					value = Math.round(value);
+				value = Math.min(Math.max(value, parameter.minimum), parameter.maximum);
+				if (value != this.parametersIn[i].value) {
+					this.module.processor_set_parameter(this.instance, index, value);
+					this.parametersIn[i].value = value;
+				}
+			}
+		}
+
+		var n = outputs[0][0].length;
+		var i = 0;
+		while (i < n) {
+			var s = Math.min(n - i, 128);
+
+			for (var j = 0; j < this.x.length; j++) {
+				var input = inputs[j];
+				if (!input.length) {
+					for (var k = 0; k < this.x[j].length; k++)
+						this.x[j][k].fill(0);
+				} else {
+					for (var k = 0; k < this.x[j].length; k++)
+						if (k <= input.length)
+							this.x[j][k].set(input[k].subarray(i, s));
+						else
+							this.x[j][k].fill(0);
+				}
+			}
+
+			this.module.processor_process(this.instance, s);
+
+			for (var j = 0; j < this.y.length; j++) {
+				var output = outputs[j];
+				for (var k = 0; k < this.y[j].length; k++)
+					this.y[j][k].set(output[k].subarray(i, s));
+			}
+
+			i += s;
+		}
+		
+		for (var i = 0; i < this.parametersOut.length; i++) {
+			var index = this.parametersOut[i].index;
+			var value = this.parametersOutValues[i];
+			if (value != this.parametersOut[i].value) {
+				this.paramOutChangeMsg.index = index;
+				this.paramOutChangeMsg.value = value;
+				this.port.postMessage(this.paramOutChangeMsg);
+				this.parametersOut[i].value = value;
+			}
+		}
+
+		return false;
+	}
+
+	static get parameterDescriptors() {
+		var ret = [];
+		for (var i = 0; i < this.parametersIn.length; i++) {
+			var p = parameters[this.parametersIn[i].index];
+			ret.push({ name: p.name, minValue: p.minimum, maxValue: p.maximum, defaultValue: p.defaultValue, automationRate: "k-rate" });
+		}
+		return ret;
+	}
+}
+
+registerProcessor("{{=it.product.bundleName}}", Processor);
diff --git a/templates/web/tibia-index.js b/templates/web/tibia-index.js
index f9cf682..ccad3af 100644
--- a/templates/web/tibia-index.js
+++ b/templates/web/tibia-index.js
@@ -4,6 +4,7 @@ var sep = path.sep;
 module.exports = function (data, api) {
 	api.copyFile(`src${sep}memset.h`, `src${sep}memset.h`);
 	api.copyFile(`src${sep}walloc.h`, `src${sep}walloc.h`);
-	api.copyFile(`src${sep}wrapper.c`, `src${sep}wrapper.c`);
+	api.copyFile(`src${sep}processor.c`, `src${sep}processor.c`);
 	api.generateFileFromTemplateFile(`src${sep}data.h`, `src${sep}data.h`, data);
+	api.generateFileFromTemplateFile(`src${sep}processor.js`, `src${sep}processor.js`, data);
 };