diff --git a/arduino/libretuya/api/WiFiClient.h b/arduino/libretuya/api/WiFiClient.h
index 5a0c22a..32dcb0d 100644
--- a/arduino/libretuya/api/WiFiClient.h
+++ b/arduino/libretuya/api/WiFiClient.h
@@ -24,41 +24,46 @@
 
 class IWiFiClient : public Client {
   public:
-	IWiFiClient(int fd) {}
+	IWiFiClient() {}
 
-	int connect(IPAddress ip, uint16_t port, int32_t timeout);
-	int connect(const char *host, uint16_t port, int32_t timeout);
+	IWiFiClient(int sock) {}
 
-	size_t write(Stream &stream);
+	virtual int connect(IPAddress ip, uint16_t port, int32_t timeout)	  = 0;
+	virtual int connect(const char *host, uint16_t port, int32_t timeout) = 0;
 
-	int fd() const;
-	int socket();
-	int setTimeout(uint32_t seconds);
+	virtual size_t write(Stream &stream) = 0;
 
-	IWiFiClient &operator=(const WiFiClient &other);
+	virtual int fd() const					 = 0;
+	virtual int socket()					 = 0;
+	virtual int setTimeout(uint32_t seconds) = 0;
 
-	bool operator==(const bool value) {
+	virtual IWiFiClient &operator=(const IWiFiClient &other) = 0;
+	virtual bool operator==(const IWiFiClient &other) const	 = 0;
+
+	operator bool() {
+		return connected();
+	}
+
+	virtual bool operator==(const bool value) {
 		return bool() == value;
 	}
 
-	bool operator!=(const bool value) {
+	virtual bool operator!=(const bool value) {
 		return bool() != value;
 	}
 
-	bool operator==(const IWiFiClient &);
-
-	bool operator!=(const IWiFiClient &rhs) {
-		return !this->operator==(rhs);
+	virtual bool operator!=(const IWiFiClient &other) {
+		return !this->operator==(other);
 	};
 
-	IPAddress remoteIP() const;
-	IPAddress remoteIP(int fd) const;
-	uint16_t remotePort() const;
-	uint16_t remotePort(int fd) const;
-	IPAddress localIP() const;
-	IPAddress localIP(int fd) const;
-	uint16_t localPort() const;
-	uint16_t localPort(int fd) const;
+	virtual IPAddress remoteIP() const			= 0;
+	virtual IPAddress remoteIP(int sock) const	= 0;
+	virtual uint16_t remotePort() const			= 0;
+	virtual uint16_t remotePort(int sock) const = 0;
+	virtual IPAddress localIP() const			= 0;
+	virtual IPAddress localIP(int sock) const	= 0;
+	virtual uint16_t localPort() const			= 0;
+	virtual uint16_t localPort(int sock) const	= 0;
 
 	using Print::write;
 };
diff --git a/arduino/realtek-ambz/libraries/Flash/Flash.cpp b/arduino/realtek-ambz/libraries/Flash/Flash.cpp
index 5c6f01a..d921d9e 100644
--- a/arduino/realtek-ambz/libraries/Flash/Flash.cpp
+++ b/arduino/realtek-ambz/libraries/Flash/Flash.cpp
@@ -1,5 +1,17 @@
 #include "Flash.h"
 
+#include <Arduino.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+#include <flash_api.h>
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
 FlashClass::FlashClass() {
 	flash = NULL;
 }
diff --git a/arduino/realtek-ambz/libraries/Flash/Flash.h b/arduino/realtek-ambz/libraries/Flash/Flash.h
index 3dd1c08..25b5ec1 100644
--- a/arduino/realtek-ambz/libraries/Flash/Flash.h
+++ b/arduino/realtek-ambz/libraries/Flash/Flash.h
@@ -2,15 +2,8 @@
 
 #include "api/Flash.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif // __cplusplus
-
-#include <flash_api.h>
-
-#ifdef __cplusplus
-} // extern "C"
-#endif
+struct flash_s;
+typedef struct flash_s flash_t;
 
 class FlashClass : public IFlashClass {
   private:
diff --git a/arduino/realtek-ambz/libraries/WiFi/WiFi.h b/arduino/realtek-ambz/libraries/WiFi/WiFi.h
index 80f32f5..136b7b8 100644
--- a/arduino/realtek-ambz/libraries/WiFi/WiFi.h
+++ b/arduino/realtek-ambz/libraries/WiFi/WiFi.h
@@ -15,6 +15,8 @@ extern "C" {
 } // extern "C"
 #endif
 
+#include "WiFiClient.h"
+
 class WiFiClass : public IWiFiClass,
 				  public IWiFiGenericClass,
 				  public IWiFiSTAClass,
diff --git a/arduino/realtek-ambz/libraries/WiFi/WiFiClient.cpp b/arduino/realtek-ambz/libraries/WiFi/WiFiClient.cpp
new file mode 100644
index 0000000..4d2b074
--- /dev/null
+++ b/arduino/realtek-ambz/libraries/WiFi/WiFiClient.cpp
@@ -0,0 +1,341 @@
+#include "WiFiClient.h"
+#include "WiFiPriv.h"
+
+// I think I don't understand how that works.
+// For some reason, LwIP uses a different (extern) errno,
+// while this macro refers to a function __errno, which
+// reads a totally different variable.
+#undef errno
+#include <lwip/arch.h>
+
+// disable #defines removing lwip_ prefix
+#undef LWIP_COMPAT_SOCKETS
+#define LWIP_COMPAT_SOCKETS 0
+#include <lwip/sockets.h>
+
+WiFiClient::WiFiClient() : _sock(-1), _connected(false) {
+	_timeout = WIFI_CLIENT_CONNECT_TIMEOUT;
+}
+
+WiFiClient::WiFiClient(int sock) {
+	_sock	   = sock;
+	_connected = true;
+	_rxBuffer.reset(new LwIPRxBuffer(sock));
+	_timeout = WIFI_CLIENT_CONNECT_TIMEOUT;
+}
+
+WiFiClient::~WiFiClient() {
+	stop();
+}
+
+WiFiClient &WiFiClient::operator=(const IWiFiClient &other) {
+	stop();
+	// _sock	   = other._sock;
+	// _connected = other._connected;
+	// _rxBuffer  = other._rxBuffer;
+	return *this;
+}
+
+bool WiFiClient::operator==(const IWiFiClient &other) const {
+	return _sock == other.fd() && remoteIP() == other.remoteIP() && remotePort() == other.remotePort();
+}
+
+int WiFiClient::connect(IPAddress ip, uint16_t port) {
+	return connect(ip, port, _timeout);
+}
+
+int WiFiClient::connect(const char *host, uint16_t port) {
+	return connect(host, port, _timeout);
+}
+
+int WiFiClient::connect(const char *host, uint16_t port, int32_t timeout) {
+	IPAddress ip = WiFi.hostByName(host);
+	if (!ip)
+		return 0;
+	return connect(ip, port, timeout);
+}
+
+int WiFiClient::connect(IPAddress ip, uint16_t port, int32_t timeout) {
+	int sock = lwip_socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+	if (sock < 0) {
+		return -1;
+	}
+
+	lwip_fcntl(sock, F_SETFL, lwip_fcntl(sock, F_GETFL, 0) | O_NONBLOCK);
+
+	struct sockaddr_in addr;
+	memset(&addr, 0, sizeof(addr));
+	addr.sin_family		 = AF_INET;
+	addr.sin_addr.s_addr = ip;
+	addr.sin_port		 = htons(port);
+	fd_set fdset;
+	struct timeval tv;
+	FD_ZERO(&fdset);
+	FD_SET(sock, &fdset);
+	tv.tv_sec  = 0;
+	tv.tv_usec = timeout * 1000;
+
+	int res = lwip_connect(sock, (struct sockaddr *)&addr, sizeof(addr));
+	if (res < 0 && errno != EINPROGRESS) {
+		printf("lwip_connect() errno %d\r\n", errno);
+		lwip_close(sock);
+		return -1;
+	}
+
+	res = lwip_select(sock + 1, NULL, &fdset, NULL, timeout < 0 ? NULL : &tv);
+	if (res < 0) {
+		printf("lwip_select() errno %d\r\n", errno);
+		lwip_close(sock);
+		return 0;
+	}
+	if (res == 0) {
+		printf("lwip_select() timeout errno %d\r\n", errno);
+		lwip_close(sock);
+		return 0;
+	}
+
+	int sockerr;
+	socklen_t len = (socklen_t)sizeof(sockerr);
+	res			  = lwip_getsockopt(sock, SOL_SOCKET, SO_ERROR, &sockerr, &len);
+
+	if (res < 0 || sockerr != 0) {
+		lwip_close(sock);
+		return 0;
+	}
+
+	int enable = 1;
+	lwip_setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout));
+	lwip_setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout));
+	lwip_setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, &enable, sizeof(enable));
+	lwip_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, &enable, sizeof(enable));
+
+	lwip_fcntl(sock, F_SETFL, lwip_fcntl(sock, F_GETFL, 0) & ~O_NONBLOCK);
+
+	if (_sock != -1)
+		lwip_close(_sock);
+	_sock	   = sock;
+	_connected = true;
+	_rxBuffer.reset(new LwIPRxBuffer(_sock));
+	return 1;
+}
+
+size_t WiFiClient::write(uint8_t data) {
+	return write(&data, 1);
+}
+
+size_t WiFiClient::write(Stream &stream) {
+	uint8_t *buf = (uint8_t *)malloc(1360);
+	if (!buf) {
+		return 0;
+	}
+	size_t toRead = 0, toWrite = 0, written = 0;
+	size_t available = stream.available();
+	while (available) {
+		toRead	= (available > 1360) ? 1360 : available;
+		toWrite = stream.readBytes(buf, toRead);
+		written += write(buf, toWrite);
+		available = stream.available();
+	}
+	free(buf);
+	return written;
+}
+
+size_t WiFiClient::write(const uint8_t *buf, size_t size) {
+	if (_sock < 0 || !_connected || !size) {
+		setWriteError();
+		return 0;
+	}
+
+	int retry	= WIFI_CLIENT_WRITE_RETRY;
+	int written = 0;
+	while (retry) {
+		fd_set fdset;
+		struct timeval tv;
+		FD_ZERO(&fdset);
+		FD_SET(_sock, &fdset);
+		tv.tv_sec  = 0;
+		tv.tv_usec = WIFI_CLIENT_SELECT_TIMEOUT * 1000;
+		retry--;
+
+		if (lwip_select(_sock + 1, NULL, &fdset, NULL, &tv) < 0) {
+			return 0;
+		}
+
+		if (FD_ISSET(_sock, &fdset)) {
+			int res = lwip_send(_sock, buf, size, MSG_DONTWAIT);
+			if (res > 0) {
+				written += res;
+				if (res >= size) {
+					retry = 0;
+				} else {
+					buf += res;
+					size -= res;
+					retry = WIFI_CLIENT_WRITE_RETRY;
+				}
+			} else if (res < 0 && errno != EAGAIN) {
+				setWriteError(res);
+				_connected = false;
+				retry	   = 0;
+			} else {
+				// Try again
+			}
+		}
+	}
+	return written;
+}
+
+int WiFiClient::available() {
+	if (!_connected)
+		return 0;
+	int res = _rxBuffer->available();
+	if (_rxBuffer->failed()) {
+		stop();
+	}
+	return res;
+}
+
+int WiFiClient::fd() const {
+	return _sock;
+}
+
+int WiFiClient::socket() {
+	return _sock;
+}
+
+int WiFiClient::setTimeout(uint32_t seconds) {
+	Client::setTimeout(seconds * 1000);
+	lwip_setsockopt(_sock, SOL_SOCKET, SO_RCVTIMEO, &_timeout, sizeof(_timeout));
+	return lwip_setsockopt(_sock, SOL_SOCKET, SO_SNDTIMEO, &_timeout, sizeof(_timeout));
+}
+
+int WiFiClient::read() {
+	uint8_t data;
+	int res = read(&data, 1);
+	if (res < 0)
+		return res;
+	if (res == 0)
+		return -1;
+	return data;
+}
+
+int WiFiClient::read(uint8_t *buf, size_t size) {
+	int res = -1;
+	if (_rxBuffer) {
+		res = _rxBuffer->read(buf, size);
+		if (_rxBuffer->failed()) {
+			stop();
+		}
+	}
+	return res;
+}
+
+int WiFiClient::peek() {
+	int res = -1;
+	if (_rxBuffer) {
+		res = _rxBuffer->peek();
+		if (_rxBuffer->failed()) {
+			stop();
+		}
+	}
+	return res;
+}
+
+void WiFiClient::flush() {
+	int res;
+	size_t len = available();
+	if (!len)
+		return;
+	uint8_t *buf = (uint8_t *)malloc(WIFI_CLIENT_FLUSH_BUF_SIZE);
+	if (!buf)
+		return;
+	while (len) {
+		res = lwip_recv(_sock, buf, LWIP_MIN(len, WIFI_CLIENT_FLUSH_BUF_SIZE), MSG_DONTWAIT);
+		if (res < 0) {
+			stop();
+			break;
+		}
+		len -= res;
+	}
+	free(buf);
+}
+
+void WiFiClient::stop() {
+	if (_sock != -1)
+		lwip_close(_sock);
+	_sock	   = -1;
+	_connected = false;
+	_rxBuffer  = NULL;
+}
+
+uint8_t WiFiClient::connected() {
+	if (_connected) {
+		uint8_t dummy;
+		if (lwip_recv(_sock, &dummy, 0, MSG_DONTWAIT) < 0) {
+			switch (errno) {
+				case EWOULDBLOCK:
+				case ENOENT: // caused by vfs
+					_connected = true;
+					break;
+				case ENOTCONN:
+				case EPIPE:
+				case ECONNRESET:
+				case ECONNREFUSED:
+				case ECONNABORTED:
+					_connected = false;
+					break;
+				default:
+					_connected = true;
+					break;
+			}
+		}
+	}
+	return _connected;
+}
+
+IPAddress getaddr(int sock, int (*func)(int, struct sockaddr *, socklen_t *)) {
+	struct sockaddr addr;
+	socklen_t len = sizeof(addr);
+	func(sock, &addr, &len);
+	struct sockaddr_in *s = (struct sockaddr_in *)&addr;
+	return IPAddress((uint32_t)(s->sin_addr.s_addr));
+}
+
+uint16_t getport(int sock, int (*func)(int, struct sockaddr *, socklen_t *)) {
+	struct sockaddr addr;
+	socklen_t len = sizeof(addr);
+	func(sock, &addr, &len);
+	struct sockaddr_in *s = (struct sockaddr_in *)&addr;
+	return ntohs(s->sin_port);
+}
+
+IPAddress WiFiClient::remoteIP() const {
+	return getaddr(_sock, lwip_getpeername);
+}
+
+IPAddress WiFiClient::remoteIP(int fd) const {
+	return getaddr(fd, lwip_getpeername);
+}
+
+uint16_t WiFiClient::remotePort() const {
+	return getport(_sock, lwip_getpeername);
+}
+
+uint16_t WiFiClient::remotePort(int fd) const {
+	return getport(fd, lwip_getpeername);
+}
+
+IPAddress WiFiClient::localIP() const {
+	return getaddr(_sock, lwip_getsockname);
+}
+
+IPAddress WiFiClient::localIP(int fd) const {
+	return getaddr(fd, lwip_getsockname);
+}
+
+uint16_t WiFiClient::localPort() const {
+	return getport(_sock, lwip_getsockname);
+}
+
+uint16_t WiFiClient::localPort(int fd) const {
+	return getport(fd, lwip_getsockname);
+}
diff --git a/arduino/realtek-ambz/libraries/WiFi/WiFiClient.h b/arduino/realtek-ambz/libraries/WiFi/WiFiClient.h
new file mode 100644
index 0000000..bfe4607
--- /dev/null
+++ b/arduino/realtek-ambz/libraries/WiFi/WiFiClient.h
@@ -0,0 +1,51 @@
+#pragma once
+
+#include <api/LwIPRxBuffer.h>
+#include <api/WiFiClient.h>
+#include <memory>
+
+class WiFiClient : public IWiFiClient {
+  private:
+	int _sock;
+	bool _connected;
+	std::shared_ptr<LwIPRxBuffer> _rxBuffer;
+
+  public:
+	WiFiClient();
+	WiFiClient(int sock);
+	~WiFiClient();
+
+	int connect(IPAddress ip, uint16_t port);
+	int connect(const char *host, uint16_t port);
+	int connect(IPAddress ip, uint16_t port, int32_t timeout);
+	int connect(const char *host, uint16_t port, int32_t timeout);
+
+	size_t write(uint8_t data);
+	size_t write(const uint8_t *buf, size_t size);
+	size_t write(Stream &stream);
+
+	int available();
+	int fd() const;
+	int socket();
+	int setTimeout(uint32_t seconds);
+
+	int read();
+	int read(uint8_t *buf, size_t size);
+	int peek();
+	void flush();
+	void stop();
+	uint8_t connected();
+
+	WiFiClient &operator=(const IWiFiClient &other);
+
+	bool operator==(const IWiFiClient &other) const;
+
+	IPAddress remoteIP() const;
+	IPAddress remoteIP(int sock) const;
+	uint16_t remotePort() const;
+	uint16_t remotePort(int sock) const;
+	IPAddress localIP() const;
+	IPAddress localIP(int sock) const;
+	uint16_t localPort() const;
+	uint16_t localPort(int sock) const;
+};
diff --git a/arduino/realtek-ambz/libraries/WiFi/WiFiPriv.h b/arduino/realtek-ambz/libraries/WiFi/WiFiPriv.h
index 09b512c..b8072aa 100644
--- a/arduino/realtek-ambz/libraries/WiFi/WiFiPriv.h
+++ b/arduino/realtek-ambz/libraries/WiFi/WiFiPriv.h
@@ -4,7 +4,19 @@
 extern "C" {
 #endif // __cplusplus
 
-#define LWIP_NETIF_HOSTNAME 1 // this is defined in PIO builder
+// these are defined in PIO builder (for IDE to understand)
+#define LWIP_TIMEVAL_PRIVATE 0
+#define LWIP_NETIF_HOSTNAME	 1
+// this should define all errno values, as well as the extern int
+#define LWIP_PROVIDE_ERRNO	 1
+#define LWIP_SO_RCVBUF		 1
+
+#define MAX_SOCK_NUM				4
+#define WIFI_CLIENT_CONNECT_TIMEOUT 3000
+#define WIFI_CLIENT_READ_TIMEOUT	3000
+#define WIFI_CLIENT_WRITE_RETRY		10
+#define WIFI_CLIENT_SELECT_TIMEOUT	1000
+#define WIFI_CLIENT_FLUSH_BUF_SIZE	1024
 
 #include <autoconf.h>
 #include <dhcp/dhcps.h>
@@ -12,6 +24,7 @@ extern "C" {
 #include <lwip/dns.h>
 #include <lwip/err.h>
 #include <lwip_netconf.h>
+#include <sys/time.h>
 #include <wifi_conf.h>
 #include <wifi_constants.h>
 #include <wifi_structures.h>
diff --git a/builder/arduino-common.py b/builder/arduino-common.py
index 7c6315d..ae9a9f2 100644
--- a/builder/arduino-common.py
+++ b/builder/arduino-common.py
@@ -16,7 +16,7 @@ env.Prepend(
     CPPPATH=[
         # fmt: off
         join(API_DIR),
-        join(LT_API_DIR), # for libretuya-api
+        join(LT_API_DIR),
         # fmt: on
     ]
 )
diff --git a/builder/frameworks/realtek-ambz-arduino.py b/builder/frameworks/realtek-ambz-arduino.py
index 59dbc9d..d92f3ed 100644
--- a/builder/frameworks/realtek-ambz-arduino.py
+++ b/builder/frameworks/realtek-ambz-arduino.py
@@ -55,9 +55,10 @@ env.Append(
         "ARDUINO_SDK",
         "ARDUINO_ARCH_AMBZ",
         f"BOARD_{family}",
-        # the SDK declares bool and #ifndef somehow doesn't work...
+        # the SDK declares bool if not defined before
+        # which conflicts with C++ built-in bool
         # so it's either -fpermissive or this:
-        ("bool", "unsigned char"),
+        ("bool", "bool"),
         # enable LwIPRxBuffer
         "LT_HAS_LWIP",
     ],
@@ -110,8 +111,6 @@ env["CPPPATH"].remove(
 # Sources
 sources_core = [
     # fmt: off
-    "+<" + CORE_DIR + "/cores/arduino/ard_socket.c>",
-    "+<" + CORE_DIR + "/cores/arduino/ard_ssl.c>",
     "+<" + CORE_DIR + "/cores/arduino/avr/dtostrf.c>",
     "+<" + CORE_DIR + "/cores/arduino/b64.cpp>",
     "+<" + CORE_DIR + "/cores/arduino/cxxabi-compat.cpp>",
@@ -123,13 +122,11 @@ sources_core = [
     "+<" + CORE_DIR + "/cores/arduino/PowerManagement.cpp>",
     "+<" + CORE_DIR + "/cores/arduino/RingBuffer.cpp>",
     "+<" + CORE_DIR + "/cores/arduino/rtl_sys.cpp>",
-    "+<" + CORE_DIR + "/cores/arduino/server_drv.cpp>",
     "+<" + CORE_DIR + "/cores/arduino/spiffs/spiffs_cache.c>",
     "+<" + CORE_DIR + "/cores/arduino/spiffs/spiffs_check.c>",
     "+<" + CORE_DIR + "/cores/arduino/spiffs/spiffs_gc.c>",
     "+<" + CORE_DIR + "/cores/arduino/spiffs/spiffs_hydrogen.c>",
     "+<" + CORE_DIR + "/cores/arduino/spiffs/spiffs_nucleus.c>",
-    "+<" + CORE_DIR + "/cores/arduino/ssl_drv.cpp>",
     "+<" + CORE_DIR + "/cores/arduino/Tone.cpp>",
     "+<" + CORE_DIR + "/cores/arduino/WebSocketClient.cpp>",
     "+<" + CORE_DIR + "/cores/arduino/WInterrupts.c>",
@@ -170,6 +167,7 @@ sources_libs = [
     "+<" + CORE_DIR +"/libraries/Flash/Flash.cpp>",
     "+<" + CORE_DIR +"/libraries/WiFi/WiFi.cpp>",
     "+<" + CORE_DIR +"/libraries/WiFi/WiFiAP.cpp>",
+    "+<" + CORE_DIR +"/libraries/WiFi/WiFiClient.cpp>",
     "+<" + CORE_DIR +"/libraries/WiFi/WiFiGeneric.cpp>",
     "+<" + CORE_DIR +"/libraries/WiFi/WiFiScan.cpp>",
     "+<" + CORE_DIR +"/libraries/WiFi/WiFiSTA.cpp>",
diff --git a/builder/frameworks/realtek-ambz-sdk.py b/builder/frameworks/realtek-ambz-sdk.py
index 1646e23..8e3d364 100644
--- a/builder/frameworks/realtek-ambz-sdk.py
+++ b/builder/frameworks/realtek-ambz-sdk.py
@@ -70,7 +70,11 @@ env.Replace(
         "CONFIG_PLATFORM_8711B",
         ("F_CPU", "166000000L"),
         ("LWIP_TIMEVAL_PRIVATE", "0"),
-        ("LWIP_NETIF_HOSTNAME", "1"),
+        ("LWIP_NETIF_HOSTNAME", "1"),  # to support hostname changing
+        ("LWIP_PROVIDE_ERRNO", "1"),  # for extern int errno and codes
+        ("LWIP_SO_RCVBUF", "1"),  # for ioctl(FIONREAD)
+        ("INT_MAX", "2147483647"),  # for RECV_BUFSIZE_DEFAULT
+        ("ERRNO", "1"),  # for LwIP
     ],
     LINKFLAGS=[
         "-mcpu=cortex-m4",