diff --git a/aos/network/web_proxy.cc b/aos/network/web_proxy.cc
index 5b50072..3e9cd8f 100644
--- a/aos/network/web_proxy.cc
+++ b/aos/network/web_proxy.cc
@@ -90,7 +90,7 @@
     : sock_(sock),
       server_(server),
       subscribers_(subscribers),
-      config_(config) {}
+      config_headers_(PackBuffer(config.span())) {}
 
 // Function called for web socket data. Parses the flatbuffer and handles it
 // appropriately.
@@ -211,7 +211,9 @@
 void Connection::OnStateChange() {
   if (peer_connection_.get() != nullptr &&
       data_channel_->state() == webrtc::DataChannelInterface::kOpen) {
-    Send(config_.buffer());
+    for (const auto &header: config_headers_) {
+      Send(header.buffer());
+    }
   }
 }
 
diff --git a/aos/network/web_proxy.h b/aos/network/web_proxy.h
index 409e61d..549a7ae 100644
--- a/aos/network/web_proxy.h
+++ b/aos/network/web_proxy.h
@@ -105,7 +105,9 @@
   ~Connection() {
     // DataChannel may call OnStateChange after this is destroyed, so make sure
     // it doesn't.
-    data_channel_->UnregisterObserver();
+    if (data_channel_) {
+      data_channel_->UnregisterObserver();
+    }
   }
 
   void HandleWebSocketData(const uint8_t *data, size_t size);
@@ -148,7 +150,7 @@
   ::seasocks::WebSocket *sock_;
   ::seasocks::Server *server_;
   const std::vector<std::unique_ptr<Subscriber>> &subscribers_;
-  const aos::FlatbufferDetachedBuffer<aos::Configuration> &config_;
+  const std::vector<FlatbufferDetachedBuffer<MessageHeader>> config_headers_;
   std::map<int, rtc::scoped_refptr<webrtc::DataChannelInterface>> channels_;
 
   rtc::scoped_refptr<webrtc::PeerConnectionInterface> peer_connection_;
diff --git a/aos/network/web_proxy_main.cc b/aos/network/web_proxy_main.cc
index c674520..227f980 100644
--- a/aos/network/web_proxy_main.cc
+++ b/aos/network/web_proxy_main.cc
@@ -62,14 +62,6 @@
   aos::FlatbufferDetachedBuffer<aos::Configuration> config =
       aos::configuration::ReadConfig(FLAGS_config);
 
-  for (size_t i = 0; i < config.message().channels()->size(); ++i) {
-    aos::Channel *channel =
-        config.mutable_message()->mutable_channels()->GetMutableObject(i);
-    channel->clear_schema();
-  }
-
-  config = aos::CopyFlatBuffer(&config.message());
-
   std::vector<std::unique_ptr<aos::web_proxy::Subscriber>> subscribers;
 
   std::thread data_thread{
diff --git a/aos/network/web_proxy_utils.cc b/aos/network/web_proxy_utils.cc
index 15aedf2..21550f8 100644
--- a/aos/network/web_proxy_utils.cc
+++ b/aos/network/web_proxy_utils.cc
@@ -3,30 +3,48 @@
 namespace aos {
 namespace web_proxy {
 
+namespace {
 // Recommended max size is 64KiB for compatibility reasons. 256KiB theoretically
 // works on chrome but seemed to have some consistency issues. Picked a size in
 // the middle which seems to work.
 constexpr size_t kPacketSize = 125000;
 
+int GetPacketCountFromSize(const int packet_size) {
+  return packet_size / kPacketSize + 1;
+}
+
+flatbuffers::Offset<flatbuffers::Vector<uint8_t>> FillOutPacketVector(
+    flatbuffers::FlatBufferBuilder *fbb, absl::Span<const uint8_t> span,
+    const int packet_index) {
+  flatbuffers::Offset<flatbuffers::Vector<uint8_t>> data_offset;
+  if (kPacketSize * (packet_index + 1) < span.size()) {
+    data_offset = fbb->CreateVector(
+        static_cast<const uint8_t *>(span.data()) + kPacketSize * packet_index,
+        kPacketSize);
+  } else {
+    const int prefix_size = kPacketSize * packet_index;
+    data_offset = fbb->CreateVector(
+        static_cast<const uint8_t *>(span.data()) + prefix_size,
+        span.size() - prefix_size);
+  }
+  return data_offset;
+}
+}  // namespace
+
 int GetPacketCount(const Context &context) {
-  return context.size / kPacketSize + 1;
+  return GetPacketCountFromSize(context.size);
 }
 
 flatbuffers::Offset<MessageHeader> PackMessage(
     flatbuffers::FlatBufferBuilder *fbb, const Context &context,
     int channel_index, int packet_index) {
-  int packet_count = GetPacketCount(context);
-  flatbuffers::Offset<flatbuffers::Vector<uint8_t>> data_offset;
-  if (kPacketSize * (packet_index + 1) < context.size) {
-    data_offset = fbb->CreateVector(
-        static_cast<const uint8_t *>(context.data) + kPacketSize * packet_index,
-        kPacketSize);
-  } else {
-    int prefix_size = kPacketSize * packet_index;
-    data_offset = fbb->CreateVector(
-        static_cast<const uint8_t *>(context.data) + prefix_size,
-        context.size - prefix_size);
-  }
+  const int packet_count = GetPacketCount(context);
+  const flatbuffers::Offset<flatbuffers::Vector<uint8_t>> data_offset =
+      FillOutPacketVector(
+          fbb,
+          absl::Span<const uint8_t>{static_cast<const uint8_t *>(context.data),
+                                    context.size},
+          packet_index);
 
   MessageHeader::Builder message_header_builder(*fbb);
   message_header_builder.add_channel_index(channel_index);
@@ -39,5 +57,27 @@
   return message_header_builder.Finish();
 }
 
+std::vector<FlatbufferDetachedBuffer<MessageHeader>> PackBuffer(
+    absl::Span<const uint8_t> span) {
+  flatbuffers::FlatBufferBuilder fbb;
+  std::vector<FlatbufferDetachedBuffer<MessageHeader>> buffers;
+  const int packet_count = GetPacketCountFromSize(span.size());
+  for (int ii = 0; ii < packet_count; ++ii) {
+    const flatbuffers::Offset<flatbuffers::Vector<uint8_t>> data_offset =
+        FillOutPacketVector(&fbb, span, ii);
+
+    MessageHeader::Builder message_header_builder(fbb);
+    message_header_builder.add_packet_count(packet_count);
+    message_header_builder.add_packet_index(ii);
+    message_header_builder.add_data(data_offset);
+    message_header_builder.add_length(span.size());
+
+    fbb.Finish(message_header_builder.Finish());
+
+    buffers.emplace_back(fbb.Release());
+  }
+  return buffers;
+}
+
 }  // namespace web_proxy
 }  // namespace aos
diff --git a/aos/network/web_proxy_utils.h b/aos/network/web_proxy_utils.h
index 0672ddc..09ad333 100644
--- a/aos/network/web_proxy_utils.h
+++ b/aos/network/web_proxy_utils.h
@@ -1,5 +1,7 @@
+#include "absl/types/span.h"
 #include "aos/network/web_proxy_generated.h"
 #include "aos/events/event_loop.h"
+#include "aos/flatbuffers.h"
 
 namespace aos {
 namespace web_proxy {
@@ -15,6 +17,10 @@
     flatbuffers::FlatBufferBuilder *fbb, const Context &context,
     int channel_index, int packet_index);
 
+// Packs the provided raw data into a series of MessageHeader's of the
+// appropriate length.
+std::vector<FlatbufferDetachedBuffer<MessageHeader>> PackBuffer(
+    absl::Span<const uint8_t> span);
 
 }  // namespace web_proxy
 }  // namespace aos
diff --git a/aos/network/www/config_handler.ts b/aos/network/www/config_handler.ts
index 6615f39..048c2ba 100644
--- a/aos/network/www/config_handler.ts
+++ b/aos/network/www/config_handler.ts
@@ -27,7 +27,7 @@
   }
 
   printConfig() {
-    for (const i = 0; i < this.config.channelsLength(); i++) {
+    for (let i = 0; i < this.config.channelsLength(); i++) {
       const channel_div = document.createElement('div');
       channel_div.classList.add('channel');
       this.tree_div.appendChild(channel_div);
diff --git a/aos/network/www/proxy.ts b/aos/network/www/proxy.ts
index 7bcf575..7491ad5 100644
--- a/aos/network/www/proxy.ts
+++ b/aos/network/www/proxy.ts
@@ -90,8 +90,8 @@
 
   // Handle messages on the DataChannel. Handles the Configuration message as
   // all other messages are sent on specific DataChannels.
-  onDataChannelMessage(e: MessageEvent): void {
-    const fbBuffer = new flatbuffers.ByteBuffer(new Uint8Array(e.data));
+  onConfigMessage(data: Uint8Array): void {
+    const fbBuffer = new flatbuffers.ByteBuffer(data);
     this.configInternal = Configuration.getRootAsConfiguration(fbBuffer);
     for (const handler of Array.from(this.configHandlers)) {
       handler(this.configInternal);
@@ -146,8 +146,8 @@
     this.rtcPeerConnection.addEventListener(
         'datachannel', (e) => this.onDataChannel(e));
     this.dataChannel = this.rtcPeerConnection.createDataChannel('signalling');
-    this.dataChannel.addEventListener(
-        'message', (e) => this.onDataChannelMessage(e));
+    this.handlers.add(
+        new Handler((data) => this.onConfigMessage(data), this.dataChannel));
     window.dc = this.dataChannel;
     this.rtcPeerConnection.addEventListener(
         'icecandidate', (e) => this.onIceCandidate(e));