diff --git a/notes b/notes
index fefd908..7f6d9d0 100644
--- a/notes
+++ b/notes
@@ -23,7 +23,46 @@ product {
 	bundleName:
 		VST3: plugin folder name, plugin .dll name, Info.plist
 		LV2: plugin folder name, plugin .dll name, manifest.ttl plugin lv2:binary
-	buses: ...
+	buses: [
+		{
+			name:
+				bus name string, required
+				VST3: BusInfo name
+				LV2: manifest.ttl lv2:port lv2:name
+			shortName:
+				bus short name string, required
+				VST3: not used
+				LV2: manifest.ttl lv2:port lv2:shortName
+			direction:
+				"input" or "output", required
+				VST3: BusInfo flags - lots of implications
+				LV2: manifest.ttl lv2:port a - lots of implications
+			type:
+				"audio" or "midi", required
+				VST3: BusInfo mediaType, ParameterInfo (channel pressure, pitch bend params) - lots of implications
+				LV2: lots of implications everywhere
+			channels:
+				"mono" or "stereo", audio type only, required
+				VST3: BusInfo channelCount, plugin get/set bus arrangements
+				LV2: manifest.ttl lv2:port - lots of implications
+			sidechain:
+				bus is not part of main audio path (sidechain)? boolean, default false
+				VST3: BusInfo busType
+				LV2: manifest.ttl lv2:port lv2:portProperty lv2:isSideChain
+			cv:
+				bus is control voltage audio-rate? boolean, audio type only, default false
+				VST3: BusInfo flags
+				LV2: manifest.ttl lv2:port a lv2:CVPort
+			control:
+				bus is the "primary control channel" (send cmds, receive responses)? boolean, midi type only, default false
+				VST3: not used
+				LV2: manifest.ttl lv2:port lv2:designation lv2:control
+			optional:
+				bus is optionally connected? boolean, default false
+				VST3: BusInfo flags, plugin initialize, activate bus, set active
+				LV2: manifest.ttl lv2:port lv2:portProperty lv2:connectionOptional
+		}
+	]
 	parameters: [
 		{
 			name:
@@ -36,8 +75,8 @@ product {
 				LV2: manifest.ttl lv2:port lv2:shortName
 			direction:
 				"input" or "output", required
-				VST3: ParameterInfo flags
-				LV2: manifest.ttl lv2:port a
+				VST3: ParameterInfo flags - lots of implications
+				LV2: manifest.ttl lv2:port a - lots of implications
 			isBypass:
 				parameter is bypass/enabled? boolean - lots of implications, default false
 				VST3: ParameterInfo, controller get/set parameter/state
diff --git a/templates/lv2/src/.lv2.c.swp b/templates/lv2/src/.lv2.c.swp
deleted file mode 100644
index a8c32bb..0000000
Binary files a/templates/lv2/src/.lv2.c.swp and /dev/null differ
diff --git a/templates/lv2/src/lv2.c b/templates/lv2/src/lv2.c
index 2cd2390..a46f40c 100644
--- a/templates/lv2/src/lv2.c
+++ b/templates/lv2/src/lv2.c
@@ -199,7 +199,9 @@ static void run(LV2_Handle instance, uint32_t sample_count) {
 
 	// from https://lv2plug.in/book
 #if DATA_PRODUCT_MIDI_INPUTS_N > 0
-	for (size_t j = 0; j < DATA_PRODUCT_MIDI_INPUTS_N; j++)
+	for (size_t j = 0; j < DATA_PRODUCT_MIDI_INPUTS_N; j++) {
+		if (i->x_midi[j] == NULL)
+			continue;
 		LV2_ATOM_SEQUENCE_FOREACH(i->x_midi[j], ev) {
 			if (ev->body.type == i->uri_midi_MidiEvent) {
 				const uint8_t * const msg = (const uint8_t *)(ev + 1);
@@ -236,6 +238,7 @@ static void run(LV2_Handle instance, uint32_t sample_count) {
 				}
 			}
 		}
+	}
 #endif
 
 	plugin_process(&i->p, i->x, i->y, sample_count);
diff --git a/templates/vst3/src/data.h b/templates/vst3/src/data.h
index f311260..1e9f1a0 100644
--- a/templates/vst3/src/data.h
+++ b/templates/vst3/src/data.h
@@ -174,5 +174,5 @@ static struct {
 #endif
 
 {{?it.product.parameters.find(x => x.isLatency)}}
-# define DATA_PARAM_LATENCY_INDEX	{{=it.product.parameters.find(x => x.isLatency).paramIndex}}
+#define DATA_PARAM_LATENCY_INDEX	{{=it.product.parameters.find(x => x.isLatency).paramIndex}}
 {{?}}
diff --git a/templates/vst3/src/vst3.c b/templates/vst3/src/vst3.c
index 6dd0f4e..cd342f5 100644
--- a/templates/vst3/src/vst3.c
+++ b/templates/vst3/src/vst3.c
@@ -56,6 +56,18 @@ typedef struct pluginInstance {
 #endif
 #if DATA_PRODUCT_CHANNELS_AUDIO_OUTPUT_N > 0
 	float *						outputs[DATA_PRODUCT_CHANNELS_AUDIO_INPUT_N];
+#endif
+#if DATA_PRODUCT_BUSES_AUDIO_INPUT_N > 0
+	char						inputsActive[DATA_PRODUCT_BUSES_AUDIO_INPUT_N];
+#endif
+#if DATA_PRODUCT_BUSES_AUDIO_OUTPUT_N > 0
+	char						outputsActive[DATA_PRODUCT_BUSES_AUDIO_OUTPUT_N];
+#endif
+#if DATA_PRODUCT_BUSES_MIDI_INPUT_N > 0
+	char						midiInputsActive[DATA_PRODUCT_BUSES_MIDI_INPUT_N];
+#endif
+#if DATA_PRODUCT_BUSES_MIDI_OUTPUT_N > 0
+	char						midiOutputsActive[DATA_PRODUCT_BUSES_MIDI_OUTPUT_N];
 #endif
 	void *						mem;
 } pluginInstance;
@@ -130,6 +142,22 @@ static Steinberg_tresult pluginInitialize(void *thisInterface, struct Steinberg_
 		if (!(parameterInfo[i].flags & Steinberg_Vst_ParameterInfo_ParameterFlags_kIsReadOnly))
 			plugin_set_parameter(&p->p, parameterData[i].index, parameterData[i].def);
 	}
+#endif
+#if DATA_PRODUCT_BUSES_AUDIO_INPUT_N > 0
+	for (size_t i = 0; i < DATA_PRODUCT_BUSES_AUDIO_INPUT_N; i++)
+		p->inputsActive[i] = 0;
+#endif
+#if DATA_PRODUCT_BUSES_AUDIO_OUTPUT_N > 0
+	for (size_t i = 0; i < DATA_PRODUCT_BUSES_AUDIO_OUTPUT_N; i++)
+		p->outputsActive[i] = 0;
+#endif
+#if DATA_PRODUCT_BUSES_MIDI_INPUT_N > 0
+	for (size_t i = 0; i < DATA_PRODUCT_BUSES_MIDI_INPUT_N; i++)
+		p->midiInputsActive[i] = 0;
+#endif
+#if DATA_PRODUCT_BUSES_MIDI_OUTPUT_N > 0
+	for (size_t i = 0; i < DATA_PRODUCT_BUSES_MIDI_OUTPUT_N; i++)
+		p->midiOutputsActive[i] = 0;
 #endif
 	p->mem = NULL;
 	return Steinberg_kResultOk;
@@ -224,17 +252,20 @@ static Steinberg_tresult pluginActivateBus(void* thisInterface, Steinberg_Vst_Me
 	TRACE("plugin activate bus\n");
 	if (index < 0)
 		return Steinberg_kInvalidArgument;
+	pluginInstance *p = (pluginInstance *)((char *)thisInterface - offsetof(pluginInstance, vtblIComponent));
 	if (type == Steinberg_Vst_MediaTypes_kAudio) {
 		if (dir == Steinberg_Vst_BusDirections_kInput) {
 #if DATA_PRODUCT_BUSES_AUDIO_INPUT_N > 0
 			if (index >= DATA_PRODUCT_BUSES_AUDIO_INPUT_N)
 				return Steinberg_kInvalidArgument;
+			p->inputsActive[index] = state;
 			return Steinberg_kResultTrue;
 #endif
 		} else if (dir == Steinberg_Vst_BusDirections_kOutput) {
 #if DATA_PRODUCT_BUSES_AUDIO_OUTPUT_N > 0
 			if (index >= DATA_PRODUCT_BUSES_AUDIO_OUTPUT_N)
 				return Steinberg_kInvalidArgument;
+			p->outputsActive[index] = state;
 			return Steinberg_kResultTrue;
 #endif
 		}
@@ -243,12 +274,14 @@ static Steinberg_tresult pluginActivateBus(void* thisInterface, Steinberg_Vst_Me
 #if DATA_PRODUCT_BUSES_MIDI_INPUT_N > 0
 			if (index >= DATA_PRODUCT_BUSES_MIDI_INPUT_N)
 				return Steinberg_kInvalidArgument;
+			p->midiInputsActive[index] = state;
 			return Steinberg_kResultTrue;
 #endif
 		} else if (dir == Steinberg_Vst_BusDirections_kOutput) {
 #if DATA_PRODUCT_BUSES_MIDI_OUTPUT_N > 0
 			if (index >= DATA_PRODUCT_BUSES_MIDI_OUTPUT_N)
 				return Steinberg_kInvalidArgument;
+			p->midiOutputsActive[index] = state;
 			return Steinberg_kResultTrue;
 #endif
 		}
@@ -264,6 +297,26 @@ static Steinberg_tresult pluginSetActive(void* thisInterface, Steinberg_TBool st
 		p->mem = NULL;
 	}
 	if (state) {
+#if DATA_PRODUCT_BUSES_AUDIO_INPUT_N > 0
+		for (size_t i = 0; i < DATA_PRODUCT_BUSES_AUDIO_INPUT_N; i++)
+			if (!p->inputsActive[i] && (busInfoAudioInput[i].flags & Steinberg_Vst_BusInfo_BusFlags_kDefaultActive))
+				return Steinberg_kResultFalse;
+#endif
+#if DATA_PRODUCT_BUSES_AUDIO_OUTPUT_N > 0
+		for (size_t i = 0; i < DATA_PRODUCT_BUSES_AUDIO_OUTPUT_N; i++)
+			if (!p->outputsActive[i] && (busInfoAudioOutput[i].flags & Steinberg_Vst_BusInfo_BusFlags_kDefaultActive))
+				return Steinberg_kResultFalse;
+#endif
+#if DATA_PRODUCT_BUSES_MIDI_INPUT_N > 0
+		for (size_t i = 0; i < DATA_PRODUCT_BUSES_MIDI_INPUT_N; i++)
+			if (!p->midiInputsActive[i] && (busInfoMidiInput[i].flags & Steinberg_Vst_BusInfo_BusFlags_kDefaultActive))
+				return Steinberg_kResultFalse;
+#endif
+#if DATA_PRODUCT_BUSES_MIDI_OUTPUT_N > 0
+		for (size_t i = 0; i < DATA_PRODUCT_BUSES_MIDI_OUTPUT_N; i++)
+			if (!p->midiOutputsActive[i] && (busInfoMidiOutput[i].flags & Steinberg_Vst_BusInfo_BusFlags_kDefaultActive))
+				return Steinberg_kResultFalse;
+#endif
 		plugin_set_sample_rate(&p->p, p->sampleRate);
 		size_t req = plugin_mem_req(&p->p);
 		if (req != 0) {
diff --git a/test/product.json b/test/product.json
index 2aea107..3bf1fd1 100644
--- a/test/product.json
+++ b/test/product.json
@@ -33,15 +33,6 @@
 				"sidechain": true,
 				"control": true,
 				"optional": true
-			},
-			{
-				"type": "midi",
-				"direction": "output",
-				"name": "MIDI output",
-				"shortName": "MIDI output",
-				"sidechain": true,
-				"control": true,
-				"optional": true
 			}
 		],
 		"parameters": [