diff --git a/src/esc.c b/src/esc.c
index 3253236..4c7a5a8 100644
--- a/src/esc.c
+++ b/src/esc.c
@@ -8,7 +8,6 @@
 #include <stdarg.h>
 #include "esc.h"
 #include "utils/socket.h"
-#include "utils/buffer.h"
 #include "proto.h"
 #include "tcp_package.h"
 #include "utils/thread.h"
@@ -18,6 +17,7 @@
 #include "tcp_messages.h"
 
 #ifdef _WIN32
+#include <windows.h>
 #define usleep Sleep
 #endif
 #ifdef __linux__
@@ -96,7 +96,11 @@ const node_endpoints_t* static_discover(const static_endpoint_discoverer_t* disc
 //TODO partial transfer
 ssize_t connection_send_tcp_package(esc_connection_t conn, tcp_package_t pkg) {
     char uuid_buf[37];
-    fprintf(stderr, "connection_send_tcp_package: %u %u %s %lu ", pkg->command, pkg->flags, esc_uuid_format(pkg->correlation_id, uuid_buf, 37), buffer_size(pkg->data));
+#ifdef _WIN32
+    fprintf(stderr, "connection_send_tcp_package: %s %u %s %llu ", get_string_for_tcp_message(pkg->command), pkg->flags, esc_uuid_format(pkg->correlation_id, uuid_buf, 37), buffer_size(pkg->data));
+#else
+    fprintf(stderr, "connection_send_tcp_package: %s %u %s %lu ", get_string_for_tcp_message(pkg->command), pkg->flags, esc_uuid_format(pkg->correlation_id, uuid_buf, 37), buffer_size(pkg->data));
+#endif
     buffer_t send_buffer = tcp_package_to_buffer(pkg);
 
     size_t send_buffer_size = buffer_size(send_buffer);
@@ -125,7 +129,11 @@ tcp_package_t connection_recv_tcp_package(esc_connection_t conn) {
     uint32_t recv_size;
     ssize_t rc;
     if ((rc = socket_recv(conn->tcp_conn, (char *)&recv_size, sizeof(uint32_t))) != 4) {
+#ifdef _WIN32
+        fprintf(stderr, "connection_recv_tcp_package: %lld %d\n", rc, socket_error(conn->tcp_conn));
+#else
         fprintf(stderr, "connection_recv_tcp_package: %ld %d\n", rc, socket_error(conn->tcp_conn));
+#endif
         return 0;
     }
     buffer_t recv_buffer = buffer_create(recv_size);
@@ -139,7 +147,11 @@ tcp_package_t connection_recv_tcp_package(esc_connection_t conn) {
     tcp_package_t recv_pkg = tcp_package_from_buffer(recv_buffer);
     buffer_destroy(recv_buffer);
     char uuid_buf[37];
-    fprintf(stderr, "connection_recv_tcp_package: %u %u %s %lu\n", recv_pkg->command, recv_pkg->flags, esc_uuid_format(recv_pkg->correlation_id, uuid_buf, 37), recv_buffer_size);
+#ifdef _WIN32
+    fprintf(stderr, "connection_recv_tcp_package: %s %u %s %llu\n", get_string_for_tcp_message(recv_pkg->command), recv_pkg->flags, esc_uuid_format(recv_pkg->correlation_id, uuid_buf, 37), buffer_size(recv_pkg->data));
+#else
+    fprintf(stderr, "connection_recv_tcp_package: %s %u %s %lu\n", get_string_for_tcp_message(recv_pkg->command), recv_pkg->flags, esc_uuid_format(recv_pkg->correlation_id, uuid_buf, 37), buffer_size(recv_pkg->data));
+#endif
     return recv_pkg;
 }
 
@@ -274,8 +286,8 @@ int esc_connection_connect(esc_connection_t conn) {
 	return 0;
 }
 
-const esc_credentials_t* esc_credentials_create(const char* username, const char* password) {
-    esc_credentials_t* creds = malloc(sizeof(struct st_credentials));
+esc_credentials_t esc_credentials_create(const char* username, const char* password) {
+    esc_credentials_t creds = malloc(sizeof(struct st_credentials));
     creds->username = username;
     creds->password = password;
     return creds;
@@ -304,7 +316,7 @@ esc_resolved_event_t* resolved_event_create(EventStore__Client__Messages__Resolv
     return ev;
 }
 
-const esc_all_events_slice_t* esc_connection_read_all_forward(esc_connection_t conn, const esc_position_t* last_checkpoint, unsigned int count, const esc_credentials_t* credentials) {
+esc_all_events_slice_t esc_connection_read_all_forward(esc_connection_t conn, const esc_position_t* last_checkpoint, unsigned int count, esc_credentials_t credentials) {
     EventStore__Client__Messages__ReadAllEvents send_msg;
     event_store__client__messages__read_all_events__init(&send_msg);
     send_msg.prepare_position = last_checkpoint ? last_checkpoint->prepare_position : 0;
@@ -329,7 +341,7 @@ const esc_all_events_slice_t* esc_connection_read_all_forward(esc_connection_t c
     EventStore__Client__Messages__ReadAllEventsCompleted *recv_msg =
         event_store__client__messages__read_all_events_completed__unpack(&conn->protobuf_c_allocator, data_size, data);
 
-    esc_all_events_slice_t* result = malloc(sizeof(struct st_all_events_slice));
+    esc_all_events_slice_t result = malloc(sizeof(struct st_all_events_slice));
     result->read_direction = "forward";
     result->is_end_of_stream = (recv_msg->events == 0 || recv_msg->n_events == 0) ? 1 : 0;
     result->from_position.prepare_position = recv_msg->prepare_position;
@@ -351,6 +363,10 @@ void esc_connection_close(esc_connection_t conn) {
 }
 
 const char* esc_position_format(const esc_position_t* position, char* buffer, size_t buf_size) {
+#ifdef _WIN32
+    snprintf(buffer, buf_size, "%llu/%llu", position->prepare_position, position->commit_position);
+#else
     snprintf(buffer, buf_size, "%lu/%lu", position->prepare_position, position->commit_position);
+#endif
     return buffer;
 }
diff --git a/src/esc.h b/src/esc.h
index 83d80ce..5e17cab 100644
--- a/src/esc.h
+++ b/src/esc.h
@@ -24,7 +24,7 @@ struct st_credentials {
     const char* username;
     const char* password;
 };
-typedef struct st_credentials esc_credentials_t;
+typedef struct st_credentials* esc_credentials_t;
 
 struct st_esc_position {
     int64_t prepare_position;
@@ -58,15 +58,15 @@ struct st_all_events_slice {
     esc_resolved_event_t** events;
     int is_end_of_stream;
 };
-typedef struct st_all_events_slice esc_all_events_slice_t;
+typedef struct st_all_events_slice* esc_all_events_slice_t;
 
 const esc_connection_settings_t* esc_default_connection_settings;
 
 // Connection
 esc_connection_t esc_connection_create(const esc_connection_settings_t* connection_settings, const char* addr, const char* connection_name);
 int esc_connection_connect(esc_connection_t conn);
-const esc_credentials_t* esc_credentials_create(const char* username, const char* password);
-const esc_all_events_slice_t* esc_connection_read_all_forward(esc_connection_t conn, const esc_position_t* last_checkpoint, unsigned int count, const esc_credentials_t* credentials);
+esc_credentials_t esc_credentials_create(const char* username, const char* password);
+esc_all_events_slice_t esc_connection_read_all_forward(esc_connection_t conn, const esc_position_t* last_checkpoint, unsigned int count, esc_credentials_t credentials);
 void esc_connection_close(esc_connection_t conn);
 
 // Utils
diff --git a/src/main.c b/src/main.c
index 0163daa..30c95b1 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,16 +1,14 @@
 #include <stdio.h>
-#ifdef __linux__
-#include <unistd.h>
-#include <assert.h>
-
-#endif
-#include "utils/mutex.h"
 #include "esc.h"
-#include "utils/queue.h"
 
 #ifdef _WIN32
+#include <winsock.h>
+#include <windows.h>
 #define usleep Sleep
 #endif
+#ifdef __linux__
+#include <unistd.h>
+#endif
 
 int main() {
 #ifdef _WIN32
@@ -25,9 +23,9 @@ int main() {
     if (esc_connection_connect(conn) != 0) {
         return -2;
     }
-    const esc_credentials_t* credentials = esc_credentials_create("admin", "changeit");
+    esc_credentials_t credentials = esc_credentials_create("admin", "changeit");
 
-    const esc_all_events_slice_t *result = 0;
+    esc_all_events_slice_t result = 0;
     do {
         result = esc_connection_read_all_forward(conn, result ? &result->next_position : NULL, 100, credentials);
         if (result == 0) {
@@ -41,7 +39,11 @@ int main() {
                result->is_end_of_stream);
         char uuid_buf[37];
         for (size_t i = 0; i < result->n_events; i++) {
+#ifdef _WIN32
+            printf("%s %s %lld@%s %llu %llu\n", esc_uuid_format(result->events[i]->event->event_id, uuid_buf, 37),
+#else
             printf("%s %s %ld@%s %lu %lu\n", esc_uuid_format(result->events[i]->event->event_id, uuid_buf, 37),
+#endif
                    result->events[i]->event->event_type,
                    result->events[i]->event->event_number,
                    result->events[i]->event->event_stream_id,
diff --git a/src/utils/socket.c b/src/utils/socket.c
index 9fc2af1..ecac208 100644
--- a/src/utils/socket.c
+++ b/src/utils/socket.c
@@ -13,6 +13,7 @@ struct st_socket {
     int af;
     int type;
     int proto;
+    int last_error;
 };
 
 socket_t socket_create(int type) {
@@ -23,16 +24,19 @@ socket_t socket_create(int type) {
         s->proto = IPPROTO_TCP;
         s->s = socket(s->af, s->type, s->proto);
         if (s->s == INVALID_SOCKET) {
-            free(s);
-            return NULL;
+            s->last_error = WSAGetLastError();
         }
         return s;
     }
     return NULL;
 }
 
-void socket_close(socket_t s) {
-    closesocket(s->s);
+int socket_close(socket_t s) {
+    int rc = closesocket(s->s);
+    if (rc != 0) {
+        s->last_error = WSAGetLastError();
+    }
+    return rc;
 }
 
 int socket_connect(socket_t s, char* addr, unsigned short port) {
@@ -43,30 +47,62 @@ int socket_connect(socket_t s, char* addr, unsigned short port) {
     hints.ai_socktype = s->type;
     hints.ai_protocol = s->proto;
     ADDRINFO* result;
-    if (getaddrinfo(addr, itoa(port, port_s, 10), &hints, &result) != 0) {
+    int rc;
+    if ((rc = getaddrinfo(addr, itoa(port, port_s, 10), &hints, &result)) != 0) {
+        s->last_error = WSAGetLastError();
         return -1;
     }
-    return connect(s->s, result->ai_addr, (int)result->ai_addrlen);
+    if ((rc = connect(s->s, result->ai_addr, (int)result->ai_addrlen)) != 0) {
+        s->last_error = WSAGetLastError();
+        return -2;
+    }
+    return 0;
 }
 
 ssize_t socket_send(socket_t s, char* data, size_t len) {
-    return send(s->s, data, (int)len, 0);
+    ssize_t rc = send(s->s, data, (int)len, 0);
+    if (rc < 0) {
+        s->last_error = WSAGetLastError();
+    }
+    return rc;
 }
 
 ssize_t socket_recv(socket_t s, char* buf, size_t len) {
-    return recv(s->s, buf, (int)len, 0);
+    ssize_t rc = recv(s->s, buf, (int)len, 0);
+    if (rc < 0) {
+        s->last_error = WSAGetLastError();
+    }
+    return rc;
 }
 
 int socket_readable(socket_t s) {
 	fd_set readable;
+    FD_ZERO(&readable);
 	FD_SET(s->s, &readable);
 	struct timeval timeout = {0, 0};
 	
-	return select(0, &readable, 0, 0, &timeout);
+	int rc = select(0, &readable, 0, 0, &timeout);
+    if (rc < 0) {
+        s->last_error = WSAGetLastError();
+    }
+    return rc;
 }
 
-int socket_error() {
-    return WSAGetLastError();
+int socket_writable(socket_t s) {
+    fd_set writable;
+    FD_ZERO(&writable);
+    FD_SET(s->s, &writable);
+    struct timeval timeout = {0, 0};
+
+    int rc = select(0, 0, &writable, 0, &timeout);
+    if (rc < 0) {
+        s->last_error = WSAGetLastError();
+    }
+    return rc;
+}
+
+int socket_error(socket_t s) {
+    return s->last_error;
 }
 #endif
 #ifdef __linux__
diff --git a/src/utils/uuid.c b/src/utils/uuid.c
index 8aad106..8d5842f 100644
--- a/src/utils/uuid.c
+++ b/src/utils/uuid.c
@@ -10,14 +10,19 @@
 
 #define UUID_SIZE 16
 
+int srand_called = 0;
+
 struct st_uuid {
     char data[UUID_SIZE];
 };
 
 //TODO: fixme - this is not secure, use crypto random bytes instead of rand
 esc_uuid_t esc_uuid_create() {
+    if (srand_called == 0) {
+        srand(time(NULL));
+        srand_called = 1;
+    }
     esc_uuid_t result = malloc(sizeof(struct st_uuid));
-    srand(time(NULL));
     for(int i=0;i<UUID_SIZE;i++)
         result->data[i] = (uint8_t)(rand() & 0xff);
     return result;
@@ -45,6 +50,16 @@ int esc_uuid_compare(esc_uuid_t left, esc_uuid_t right) {
 }
 
 const char* esc_uuid_format(esc_uuid_t uuid, char* buffer, size_t buf_size) {
+#ifdef _WIN32
+    snprintf(buffer, buf_size, "%08lx-%04hx-%04hx-%04hx-%08lx%04hx",
+             *(long*)&uuid->data[0],
+             *(short*)&uuid->data[4],
+             *(short*)&uuid->data[6],
+             *(short*)&uuid->data[8],
+             *(long*)&uuid->data[10],
+             *(short*)&uuid->data[14]);
+#endif
+#ifdef __linux__
     snprintf(buffer, buf_size, "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx",
              uuid->data[0],
              uuid->data[1],
@@ -62,5 +77,6 @@ const char* esc_uuid_format(esc_uuid_t uuid, char* buffer, size_t buf_size) {
              uuid->data[13],
              uuid->data[14],
              uuid->data[15]);
+#endif
     return buffer;
 }