diff --git a/quic/qbone/qbone_client_session.cc b/quic/qbone/qbone_client_session.cc
new file mode 100644
index 0000000..7bd401d
--- /dev/null
+++ b/quic/qbone/qbone_client_session.cc
@@ -0,0 +1,88 @@
+// Copyright (c) 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/third_party/quiche/src/quic/qbone/qbone_client_session.h"
+
+#include "net/third_party/quiche/src/quic/core/quic_types.h"
+#include "net/third_party/quiche/src/quic/platform/api/quic_ptr_util.h"
+#include "net/third_party/quiche/src/quic/qbone/qbone_constants.h"
+
+namespace quic {
+
+QboneClientSession::QboneClientSession(
+    QuicConnection* connection,
+    QuicCryptoClientConfig* quic_crypto_client_config,
+    QuicSession::Visitor* owner,
+    const QuicConfig& config,
+    const ParsedQuicVersionVector& supported_versions,
+    const QuicServerId& server_id,
+    QbonePacketWriter* writer,
+    QboneClientControlStream::Handler* handler)
+    : QboneSessionBase(connection, owner, config, supported_versions, writer),
+      server_id_(server_id),
+      quic_crypto_client_config_(quic_crypto_client_config),
+      handler_(handler) {}
+
+QboneClientSession::~QboneClientSession() {}
+
+std::unique_ptr<QuicCryptoStream> QboneClientSession::CreateCryptoStream() {
+  return QuicMakeUnique<QuicCryptoClientStream>(
+      server_id_, this, nullptr, quic_crypto_client_config_, this);
+}
+
+void QboneClientSession::Initialize() {
+  // Initialize must be called first, as that's what generates the crypto
+  // stream.
+  QboneSessionBase::Initialize();
+  static_cast<QuicCryptoClientStreamBase*>(GetMutableCryptoStream())
+      ->CryptoConnect();
+  // Register the reserved control stream.
+  QuicStreamId next_id = GetNextOutgoingBidirectionalStreamId();
+  DCHECK_EQ(next_id, QboneConstants::GetControlStreamId(
+                         connection()->transport_version()));
+  auto control_stream =
+      QuicMakeUnique<QboneClientControlStream>(this, handler_);
+  control_stream_ = control_stream.get();
+  RegisterStaticStream(std::move(control_stream),
+                       /*stream_already_counted = */ false);
+}
+
+int QboneClientSession::GetNumSentClientHellos() const {
+  return static_cast<const QuicCryptoClientStreamBase*>(GetCryptoStream())
+      ->num_sent_client_hellos();
+}
+
+int QboneClientSession::GetNumReceivedServerConfigUpdates() const {
+  return static_cast<const QuicCryptoClientStreamBase*>(GetCryptoStream())
+      ->num_scup_messages_received();
+}
+
+bool QboneClientSession::SendServerRequest(const QboneServerRequest& request) {
+  if (!control_stream_) {
+    QUIC_BUG << "Cannot send server request before control stream is created.";
+    return false;
+  }
+  return control_stream_->SendRequest(request);
+}
+
+void QboneClientSession::ProcessPacketFromNetwork(QuicStringPiece packet) {
+  SendPacketToPeer(packet);
+}
+
+void QboneClientSession::ProcessPacketFromPeer(QuicStringPiece packet) {
+  writer_->WritePacketToNetwork(packet.data(), packet.size());
+}
+
+void QboneClientSession::OnProofValid(
+    const QuicCryptoClientConfig::CachedState& cached) {}
+
+void QboneClientSession::OnProofVerifyDetailsAvailable(
+    const ProofVerifyDetails& verify_details) {}
+
+bool QboneClientSession::HasActiveRequests() const {
+  return (stream_map().size() - num_incoming_static_streams() -
+          num_outgoing_static_streams()) > 0;
+}
+
+}  // namespace quic