diff --git a/src/app.c b/src/app.c
index 50dcdd21..d6615dd0 100644
--- a/src/app.c
+++ b/src/app.c
@@ -23,6 +23,7 @@
 #include "phys.h"
 #include "rng.h"
 #include "sock.h"
+#include "host.h"
 
 struct exit_callback {
     app_exit_callback_func *func;
@@ -123,45 +124,6 @@ void app_register_exit_callback(app_exit_callback_func *func)
  * Entry point
  * ========================== */
 
-
-
-
-
-
-
-
-
-INTERNAL SOCK_RECEIVE_CALLBACK_FUNC_DEF(server_recv, address, msg)
-{
-    (UNUSED)address;
-    (UNUSED)msg;
-    DEBUGBREAKABLE;
-}
-
-INTERNAL SOCK_RECEIVE_CALLBACK_FUNC_DEF(client_recv, address, msg)
-{
-    (UNUSED)address;
-    (UNUSED)msg;
-    DEBUGBREAKABLE;
-}
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
 void app_entry_point(void)
 {
     struct temp_arena scratch = scratch_begin_no_conflict();
diff --git a/src/client.c b/src/client.c
index a1e9daf7..026c30d6 100644
--- a/src/client.c
+++ b/src/client.c
@@ -1,5 +1,7 @@
 #include "client.h"
 #include "host.h"
+#include "arena.h"
+#include "util.h"
 
 #define CHANNEL_LOOKUP_BUCKETS 4096
 
@@ -19,12 +21,12 @@ READONLY struct client_store _g_client_store_nil = { .valid = false };
 
 struct client_store *client_store_alloc(void)
 {
-    struct arena arena = ARENA_ALLOC(GIGABYTE(64));
+    struct arena arena = arena_alloc(GIGABYTE(64));
     struct client_store *store = arena_push_zero(&arena, struct client_store);
     store->arena = arena;
     store->num_channel_lookup_buckets = CHANNEL_LOOKUP_BUCKETS;
     store->channel_lookup_buckets = arena_push_array_zero(&arena, struct channel_lookup_bucket, store->num_channel_lookup_buckets);
-    store->clients = arena_dry_push(store, struct client);
+    store->clients = arena_dry_push(&arena, struct client);
     return store;
 }
 
@@ -49,6 +51,11 @@ struct client_store *client_store_from_client(struct client *client)
  * Client
  * ========================== */
 
+INTERNAL u64 hash_from_channel_id(struct host_channel_id channel_id)
+{
+    return hash_fnv64(HASH_FNV64_BASIS, STRING_FROM_STRUCT(&channel_id));
+}
+
 struct client *client_from_handle(struct client_store *store, struct client_handle handle)
 {
     if (handle.gen != 0 && handle.idx < store->clients_reserved) {
@@ -65,7 +72,7 @@ struct client *client_from_channel_id(struct client_store *store, struct host_ch
     struct client *res = client_nil();
     u64 channel_hash = hash_from_channel_id(channel_id);
     u64 bucket_index = channel_hash % store->num_channel_lookup_buckets;
-    struct channel_lookup_bucket *bucket = &store->channel_lookup_buckets[index];
+    struct channel_lookup_bucket *bucket = &store->channel_lookup_buckets[bucket_index];
     for (struct client *client = bucket->first; client; client = client->next_hash) {
         if (client->channel_hash == channel_hash) {
             res = client;
@@ -75,7 +82,7 @@ struct client *client_from_channel_id(struct client_store *store, struct host_ch
     return res;
 }
 
-struct client client_alloc(struct client_store *store, struct host_channel_id channel_id)
+struct client *client_alloc(struct client_store *store, struct host_channel_id channel_id)
 {
     struct client *client = NULL;
     struct client_handle handle = ZI;
@@ -90,7 +97,7 @@ struct client client_alloc(struct client_store *store, struct host_channel_id ch
         handle.idx = store->clients_reserved;
         ++store->clients_reserved;
     }
-    client = _g_client_nil;
+    *client = _g_client_nil;
     client->valid = true;
     client->handle = handle;
 
@@ -100,7 +107,7 @@ struct client client_alloc(struct client_store *store, struct host_channel_id ch
 
     /* Insert into channel lookup */
     u64 bucket_index = channel_hash % store->num_channel_lookup_buckets;
-    struct channel_lookup_bucket *bucket = &store->channel_lookup_buckets[index];
+    struct channel_lookup_bucket *bucket = &store->channel_lookup_buckets[bucket_index];
     if (bucket->last) {
         bucket->last->next_hash = client;
         client->prev_hash = bucket->last;
@@ -108,6 +115,7 @@ struct client client_alloc(struct client_store *store, struct host_channel_id ch
         bucket->first = client;
     }
     bucket->last = client;
+    return client;
 }
 
 void client_release(struct client *client)
@@ -119,9 +127,8 @@ void client_release(struct client *client)
     store->first_free_client = client;
 
     /* Remove from channel lookup */
-    u64 channel_hash = hash_from_channel_id(channel_id);
-    u64 bucket_index = channel_hash % store->num_channel_lookup_buckets;
-    struct channel_lookup_bucket *bucket = &store->channel_lookup_buckets[index];
+    u64 bucket_index = client->channel_hash % store->num_channel_lookup_buckets;
+    struct channel_lookup_bucket *bucket = &store->channel_lookup_buckets[bucket_index];
     struct client *prev = client->prev_hash;
     struct client *next = client->next_hash;
     if (prev) {
diff --git a/src/client.h b/src/client.h
index 1a54aa71..a38cb952 100644
--- a/src/client.h
+++ b/src/client.h
@@ -9,7 +9,11 @@ struct client_handle {
 
 struct client {
     b32 valid;
+    struct client_handle handle;
+
     struct host_channel_id channel_id;
+    u64 channel_hash;
+
     struct client *next_free;
     struct client *next_hash;
     struct client *prev_hash;
@@ -23,12 +27,14 @@ struct channel_lookup_bucket {
 };
 
 struct client_store {
+    b32 valid;
     struct arena arena;
 
-    struct channel_lookup_bucket channel_lookup_buckets;
+    struct channel_lookup_bucket *channel_lookup_buckets;
     u64 num_channel_lookup_buckets;
 
     struct client *clients;
+    struct client *first_free_client;
     u64 clients_reserved;
 };
 
@@ -38,7 +44,7 @@ INLINE struct client *client_nil(void)
     return &_g_client_nil;
 }
 
-INLINE struct client *client_store_nil(void)
+INLINE struct client_store *client_store_nil(void)
 {
     extern READONLY struct client_store _g_client_store_nil;
     return &_g_client_store_nil;
@@ -49,7 +55,7 @@ void client_store_release(struct client_store *store);
 struct client_store *client_store_from_client(struct client *client);
 struct client *client_from_handle(struct client_store *store, struct client_handle handle);
 struct client *client_from_channel_id(struct client_store *store, struct host_channel_id channel_id);
-struct client client_alloc(struct client_store *store, struct host_channel_id channel_id);
+struct client *client_alloc(struct client_store *store, struct host_channel_id channel_id);
 void client_release(struct client *client);
 
 #endif
diff --git a/src/common.h b/src/common.h
index 66f6570e..11edc3a3 100644
--- a/src/common.h
+++ b/src/common.h
@@ -506,6 +506,11 @@ struct space_entry_handle {
     u64 gen;
 };
 
+struct host_channel_id {
+    u32 gen;
+    u32 idx;
+};
+
 /* ========================== *
  * Tag structs
  * ========================== */
diff --git a/src/entity.h b/src/entity.h
index 623ebfca..51d5f2a0 100644
--- a/src/entity.h
+++ b/src/entity.h
@@ -4,6 +4,7 @@
 #include "sprite.h"
 #include "mixer.h"
 #include "phys.h"
+#include "client.h"
 
 enum entity_prop {
     ENTITY_PROP_NONE,
@@ -154,6 +155,12 @@ struct entity {
     /* ENTITY_PROP_MOUSE_JOINT */
     struct phys_mouse_joint mouse_joint_data;
 
+    /* ====================================================================== */
+    /* Player */
+
+    /* ENTITY_PROP_PLAYER_CONTROLLED */
+    struct client_handle controlling_client;
+
     /* ====================================================================== */
     /* Control */
 
diff --git a/src/game.c b/src/game.c
index f9bdf78e..e0b096f4 100644
--- a/src/game.c
+++ b/src/game.c
@@ -16,6 +16,7 @@
 #include "space.h"
 #include "byteio.h"
 #include "client.h"
+#include "host.h"
 
 GLOBAL struct {
     struct atomic_i32 game_thread_shutdown;
@@ -68,14 +69,10 @@ struct game_startup_receipt game_startup(struct mixer_startup_receipt *mixer_sr,
     (UNUSED)phys_sr;
     (UNUSED)host_sr;
 
-    /* Initialize game input storage */
-    G.game_input_mutex = sys_mutex_alloc();
-    G.game_input_arena = arena_alloc(GIGABYTE(64));
-
     G.client_store = client_store_alloc();
 
     /* Intialize host */
-    struct host_address_desc bind_address = HOST_ADDRESS_ALL_LOCAL_INTERFACES(12345);
+    struct sock_address bind_address = sock_address_from_any_local_interface_with_port(12345);
     G.host = host_alloc(bind_address);
 
     /* Initialize empty world */
@@ -119,7 +116,6 @@ INTERNAL void reset_world(void)
 
     /* Re-create world */
     world_alloc(&G.tick);
-    G.tick.continuity_gen = atomic_u64_eval(&G.prev_tick_continuity_gen) + 1;
     G.tick.timescale = GAME_TIMESCALE;
 }
 
@@ -437,7 +433,7 @@ INTERNAL PHYS_COLLISION_CALLBACK_FUNC_DEF(on_collision, array)
  * Update
  * ========================== */
 
-INTERNAL void game_update()
+INTERNAL void game_update(void)
 {
     __prof;
 
@@ -535,7 +531,7 @@ INTERNAL void game_update()
 
     struct game_cmd_list game_cmds = ZI;
     {
-        struct host_event_array host_events = host_events_pop(scratch.arena, G.host);
+        struct host_event_array host_events = host_pop_events(scratch.arena, &G.host);
         game_cmds_from_host_events(scratch.arena, host_events, &game_cmds);
     }
 
@@ -545,10 +541,10 @@ INTERNAL void game_update()
 
     for (struct game_cmd *cmd = game_cmds.first; cmd; cmd = cmd->next) {
         enum game_cmd_kind kind = cmd->kind;
-        struct host_channel_id channel_id = cmd->client_channel_id;
+        struct host_channel_id channel_id = cmd->channel_id;
 
-        struct client *client = client_from_channel_id(channel_id);
-        if (client->valid || channel_id == HOST_CHANNEL_ID_NIL) {
+        struct client *client = client_from_channel_id(G.client_store, channel_id);
+        if (client->valid || host_channel_id_is_nil(channel_id)) {
             switch (kind) {
                 /* Cursor */
                 case GAME_CMD_KIND_CURSOR_MOVE:
@@ -573,9 +569,9 @@ INTERNAL void game_update()
                 case GAME_CMD_KIND_CLIENT_DISCONNECT:
                 {
                     if (client->valid) {
-                        struct entity *client_ent = entity_from_handle(client->ent);
+                        struct entity *client_ent = entity_from_handle(entity_store, client->ent);
                         if (client_ent->valid) {
-                            entity_disable_prop(client_ent, ENTITY_PROP_CLIENT_CONTROLLED);
+                            entity_disable_prop(client_ent, ENTITY_PROP_PLAYER_CONTROLLED);
                             entity_enable_prop(client_ent, ENTITY_PROP_RELEASE_NEXT_TICK);
                             host_queue_disconnect(&G.host, channel_id);
                         }
@@ -585,12 +581,12 @@ INTERNAL void game_update()
 
                 default: break;
             };
-        } else if (kind == GAME_CMD_KIND_CLIENT_CONNECT && channel_id != HOST_CHANNEL_ID_NIL && !client->valid) {
+        } else if (kind == GAME_CMD_KIND_CLIENT_CONNECT && !host_channel_id_is_nil(channel_id) && !client->valid) {
             /* Connect client */
-            struct client *client = client_alloc(G.client_store, channel_id);
-            struct client_ent *client_ent = entity_alloc(root);
-            entity_enable_prop(client_ent, ENTITY_PROP_CLIENT_CONTROLLED);
-            client_ent->client_handle = client->handle;
+            client = client_alloc(G.client_store, channel_id);
+            struct entity *client_ent = entity_alloc(root);
+            entity_enable_prop(client_ent, ENTITY_PROP_PLAYER_CONTROLLED);
+            client_ent->controlling_client = client->handle;
         }
     }
 
@@ -1322,19 +1318,21 @@ INTERNAL void game_update()
         struct temp_arena temp = arena_temp_begin(scratch.arena);
 
         /* TODO: Not like this */
-        struct game_event_desc snapshot_ed = ZI;
-        snapshot_ed.kind = GAME_EVENT_KIND_SNAPSHOT_FULL;
-        snapshot_ed.data = game_string_from_tick(&G.tick);
+        struct game_event snapshot_event = ZI;
+        snapshot_event.kind = GAME_EVENT_KIND_SNAPSHOT_FULL;
+        snapshot_event.snapshot_data = game_string_from_tick(temp.arena, &G.tick);
 
-        struct host_msg_desc msg = ZI;
-        msg.channel = HOST_CHANNEL_ALL;
-        msg.data = snapshot;
-        host_queue_write(G.host, msg);
+        struct game_event_list l = ZI;
+        l.first = &snapshot_event;
+        l.last = &snapshot_event;
+        struct string msg = game_string_from_events(temp.arena, l);
 
-        temp_arena_end(temp);
+        host_queue_write(&G.host, HOST_CHANNEL_ID_ALL, msg);
+
+        arena_temp_end(temp);
     }
 
-    host_update(G.host);
+    host_update(&G.host);
     __profframe("Game");
 
     /* ========================== *
@@ -1354,7 +1352,7 @@ struct string game_string_from_cmds(struct arena *arena, struct game_cmd_list cm
 {
     struct byte_writer bw = bw_from_arena(arena);
 
-    for (struct game_cmd *cmd = cmds->first; cmd; cmd = cmd->next) {
+    for (struct game_cmd *cmd = cmds.first; cmd; cmd = cmd->next) {
         struct byte_writer bw_size = bw_branch(&bw, sizeof(u64));
         u64 start = bw_pos(&bw);
 
@@ -1387,11 +1385,11 @@ struct string game_string_from_cmds(struct arena *arena, struct game_cmd_list cm
     return bw_get_written(&bw);
 }
 
-void game_cmds_from_host_events(struct arena *arena, struct host_event_array host_events, struct game_cmd *cmds_out)
+void game_cmds_from_host_events(struct arena *arena, struct host_event_array host_events, struct game_cmd_list *cmds_out)
 {
     for (u64 i = 0; i < host_events.count; ++i) {
         struct game_cmd *cmd = arena_push_zero(arena, struct game_cmd);
-        struct host_channel_event host_event = host_events.events[i];
+        struct host_event host_event = host_events.events[i];
         enum host_event_kind host_event_kind = host_event.kind;
         cmd->channel_id = host_event.channel_id;
         switch (host_event_kind) {
@@ -1408,7 +1406,7 @@ void game_cmds_from_host_events(struct arena *arena, struct host_event_array hos
 
             case HOST_EVENT_KIND_MSG:
             {
-                struct byte_reader br = br_from_buffer(event.msg);
+                struct byte_reader br = br_from_buffer(host_event.msg);
                 while (br_bytes_left(&br) > 0) {
                     u64 cmd_size = br_read_u64(&br);
                     u64 cmd_pos_end = br_pos(&br) + cmd_size;
@@ -1459,11 +1457,11 @@ void game_cmds_from_host_events(struct arena *arena, struct host_event_array hos
 struct string game_string_from_events(struct arena *arena, struct game_event_list events)
 {
     struct byte_writer bw = bw_from_arena(arena);
-    for (struct game_cmd *cmd = cmds->first; cmd; cmd = cmd->next) {
+    for (struct game_event *event = events.first; event; event = event->next) {
         struct byte_writer bw_size = bw_branch(&bw, sizeof(u64));
         u64 start = bw_pos(&bw);
 
-        switch (cmd->kind) {
+        switch (event->kind) {
             case GAME_EVENT_KIND_SNAPSHOT_FULL:
             {
             } break;
@@ -1477,34 +1475,34 @@ struct string game_string_from_events(struct arena *arena, struct game_event_lis
     return bw_get_written(&bw);
 }
 
-void game_events_from_host_events(struct arena *arena, struct host_event_array host_events, struct game_event *events_out)
+void game_events_from_host_events(struct arena *arena, struct host_event_array host_events, struct game_event_list *events_out)
 {
     for (u64 i = 0; i < host_events.count; ++i) {
-        struct game_event *event = arena_push_zero(arena, struct game_event);
-        struct host_channel_event host_event = host_events.events[i];
+        struct game_event *game_event = arena_push_zero(arena, struct game_event);
+        struct host_event host_event = host_events.events[i];
         enum host_event_kind host_event_kind = host_event.kind;
-        event->channel_id = host_event.channel_id;
+        game_event->channel_id = host_event.channel_id;
         switch (host_event_kind) {
             case HOST_EVENT_KIND_CHANNEL_OPENED:
             {
-                event->kind = GAME_EVENT_KIND_CONNECT;
+                game_event->kind = GAME_EVENT_KIND_CONNECT;
             } break;
 
             case HOST_EVENT_KIND_CHANNEL_CLOSED:
             {
-                event->kind = GAME_EVENT_KIND_DISCONNECT;
-                event->disconnect_reason = LIT("Connection lost");
+                game_event->kind = GAME_EVENT_KIND_DISCONNECT;
+                game_event->disconnect_reason = LIT("Connection lost");
             } break;
 
             case HOST_EVENT_KIND_MSG:
             {
-                struct byte_reader br = br_from_buffer(event.msg);
+                struct byte_reader br = br_from_buffer(host_event.msg);
                 while (br_bytes_left(&br) > 0) {
                     u64 event_size = br_read_u64(&br);
                     u64 event_pos_end = br_pos(&br) + event_size;
 
-                    event->kind = br_read_i8(&br);
-                    switch (event->kind) {
+                    game_event->kind = br_read_i8(&br);
+                    switch (game_event->kind) {
                         case GAME_EVENT_KIND_SNAPSHOT_FULL:
                         {
                         } break;
@@ -1521,14 +1519,33 @@ void game_events_from_host_events(struct arena *arena, struct host_event_array h
         }
 
         if (events_out->last) {
-            events_out->last->next = cmd;
+            events_out->last->next = game_event;
         } else {
-            events_out->first = cmd;
+            events_out->first = game_event;
         }
-        events_out->last = cmd;
+        events_out->last = game_event;
     }
 }
 
+/* ========================== *
+ * Snapshot
+ * ========================== */
+
+struct string game_string_from_tick(struct arena *arena, struct world *tick)
+{
+    (UNUSED)arena;
+    (UNUSED)tick;
+
+    struct string res = ZI;
+    return res;
+}
+
+void game_tick_from_string(struct string str, struct world *tick_out)
+{
+    (UNUSED)str;
+    (UNUSED)tick_out;
+}
+
 /* ========================== *
  * Game thread
  * ========================== */
@@ -1536,8 +1553,6 @@ void game_events_from_host_events(struct arena *arena, struct host_event_array h
 
 INTERNAL SYS_THREAD_ENTRY_POINT_FUNC_DEF(game_thread_entry_point, arg)
 {
-    struct temp_arena scratch = scratch_begin_no_conflict();
-
     (UNUSED)arg;
     i64 last_frame_ns = 0;
     i64 target_dt_ns = NS_FROM_SECONDS(GAME_FPS > (0) ? (1.0 / GAME_FPS) : 0);
diff --git a/src/game.h b/src/game.h
index 4eaf36b4..1099d5a7 100644
--- a/src/game.h
+++ b/src/game.h
@@ -1,6 +1,8 @@
 #ifndef GAME_H
 #define GAME_H
 
+#include "host.h"
+
 struct world;
 struct mixer_startup_receipt;
 struct sprite_startup_receipt;
@@ -84,7 +86,7 @@ struct game_cmd_list {
 };
 
 struct string game_string_from_cmds(struct arena *arena, struct game_cmd_list cmds);
-void game_cmds_from_host_events(struct arena *arena, struct host_event_array host_events, struct game_cmd *cmds_out);
+void game_cmds_from_host_events(struct arena *arena, struct host_event_array host_events, struct game_cmd_list *cmds_out);
 
 /* ========================== *
  * Game event
@@ -104,9 +106,13 @@ enum game_event_kind {
 
 struct game_event {
     enum game_event_kind kind;
+    struct host_channel_id channel_id;
 
-    struct entity_handle entity;
-    struct string update_data;
+    struct string snapshot_data;
+    struct string disconnect_reason;
+
+    //struct entity_handle entity;
+    //struct string update_data;
 
     struct game_event *next;
 };
@@ -117,6 +123,13 @@ struct game_event_list {
 };
 
 struct string game_string_from_events(struct arena *arena, struct game_event_list events);
-void game_events_from_host_events(struct arena *arena, struct host_event_array host_events, struct game_event *events_out);
+void game_events_from_host_events(struct arena *arena, struct host_event_array host_events, struct game_event_list *events_out);
+
+/* ========================== *
+ * Snapshot
+ * ========================== */
+
+struct string game_string_from_tick(struct arena *arena, struct world *tick);
+void game_tick_from_string(struct string str, struct world *tick_out);
 
 #endif
diff --git a/src/host.c b/src/host.c
index a4c684ed..3d42e7f5 100644
--- a/src/host.c
+++ b/src/host.c
@@ -2,6 +2,7 @@
 #include "arena.h"
 #include "scratch.h"
 #include "byteio.h"
+#include "sys.h"
 
 //#define HOST_NETWORK_ADDRESS_STRING(str)
 //#define HOST_NETWORK_ADDRESS_ALL_LOCAL_INTERFACES(port)
@@ -10,69 +11,81 @@
 #define PACKET_MAGIC 0xd9e3b8b6
 #define PACKET_CHUNK_MAX_LEN 256
 
-GLOBAL struct {
-    i32 _;
-} G = ZI, DEBUG_ALIAS(G, G_host);
+/* Give enough space for msg chunk + header */
+#define PACKET_DATA_MAX_LEN (PACKET_CHUNK_MAX_LEN * 2)
 
-
-struct host_address_desc {
-    i32 _;
+enum packet_kind {
+    PACKET_KIND_NONE,
+    PACKET_KIND_TRY_CONNECT,
+    PACKET_KIND_CONNECT_SUCCESS,
+    PACKET_KIND_DISCONNECT,
+    PACKET_KIND_MSG_CHUNK
 };
 
-struct host_channel_id {
-    u32 idx;
-    u32 gen;
+enum packet_flag {
+    PACKET_FLAG_NONE        = 0,
+    PACKET_FLAG_RELIABLE    = (1 << 0)
+};
+
+struct packet {
+    u64 seq;
+    u8 flags;
+    u64 data_len;
+    u8 data[PACKET_DATA_MAX_LEN];
+
+    struct packet *next;
 };
 
 struct host_channel {
     b32 valid;
+    b32 connected;
+    struct host *host;
+
     struct host_channel_id id;
+    struct sock_address address;
+
+    struct packet *first_reliable_packet;
+    struct packet *last_reliable_packet;
+    struct packet *first_unreliable_packet;
+    struct packet *last_unreliable_packet;
+
+    u64 their_acked_seq;
+    u64 our_acked_seq;
 };
 
-enum host_cmd_kind {
-    HOST_CMD_KIND_NONE,
-
-    HOST_CMD_KIND_CONNECT,
-    HOST_CMD_KIND_DISCONNECT,
-    HOST_CMD_KIND_WRITE
+struct host_channel_node {
+    struct host_channel *channel;
+    struct host_channel_node *next;
 };
 
-enum host_event_kind {
-    HOST_EVENT_KIND_NONE,
-
-    HOST_EVENT_KIND_CHANNEL_OPENED,
-    HOST_EVENT_KIND_CHANNEL_CLOSED,
-    HOST_EVENT_KIND_MSG
+struct host_channel_list {
+    struct host_channel_node *first;
+    struct host_channel_node *last;
 };
 
-struct host_cmd {
-    enum host_cmd_kind kind;
-    struct host_cmd *next;
+struct host_queued_event {
+    struct host_event event;
+    struct host_queued_event *next;
 };
 
-struct host_event {
-    enum host_event_kind kind;
+struct recv_buffer {
+    u64 msg_id;
+
+    u64 last_chunk_len;
+    u64 num_chunks_total;
+    u64 num_chunks_received;
+
+    i64 touched_ns;
+
+    u8 *chunks_received_bitmap;
+    u8 *data;
 };
 
-struct host {
-    struct arena cmd_arena;
-    struct host_cmd *first_cmd;
-    struct host_cmd *last_cmd;
-    struct host_cmd *first_free_cmd;
-
-    struct arena channels_arena;
-    struct host_channel *channels;
-    u64 channels_reserved;
-};
-
-
-
-
-
-
-
-
+READONLY GLOBAL struct host_channel _g_host_channel_nil = { .valid = false };
 
+GLOBAL struct {
+    i32 _;
+} G = ZI, DEBUG_ALIAS(G, G_host);
 
 /* ========================== *
  * Startup
@@ -86,37 +99,144 @@ struct host_startup_receipt host_startup(struct sock_startup_receipt *sock_sr)
 }
 
 /* ========================== *
- * Allocation
+ * Host
  * ========================== */
 
-struct host host_alloc(struct host_address_desc bind_address)
+struct host host_alloc(struct sock_address bind_address)
 {
     struct host host = ZI;
     host.cmd_arena = arena_alloc(GIGABYTE(64));
+    host.queued_event_arena = arena_alloc(GIGABYTE(64));
+    host.packet_arena = arena_alloc(GIGABYTE(64));
     host.channels_arena = arena_alloc(GIGABYTE(64));
+    host.sock = sock_alloc(bind_address, SOCK_FLAG_NON_BLOCKING);
     return host;
 }
 
 void host_release(struct host *host)
 {
+    sock_release(&host->sock);
     arena_release(&host->channels_arena);
+    arena_release(&host->packet_arena);
+    arena_release(&host->queued_event_arena);
     arena_release(&host->cmd_arena);
 }
 
+/* ========================== *
+ * Channel
+ * ========================== */
+
+INTERNAL struct host_channel *host_channel_from_address(struct host *host, struct sock_address address)
+{
+    (UNUSED)host;
+    (UNUSED)address;
+
+    struct host_channel *res = &_g_host_channel_nil;
+    return res;
+}
+
+INTERNAL struct host_channel_list host_channels_from_id(struct arena *arena, struct host *host, struct host_channel_id channel_id)
+{
+    (UNUSED)arena;
+    (UNUSED)host;
+    (UNUSED)channel_id;
+
+    struct host_channel_list res = ZI;
+    return res;
+}
+
+INTERNAL struct host_channel *host_channel_alloc(struct host *host, struct sock_address address)
+{
+    (UNUSED)host;
+    (UNUSED)address;
+
+    struct host_channel *res = NULL;
+    return res;
+}
+
+INTERNAL void host_channel_release(struct host_channel *channel)
+{
+    (UNUSED)channel;
+}
+
+INTERNAL struct recv_buffer *host_channel_get_recv_buffer(struct host_channel *channel, u64 msg_id)
+{
+    (UNUSED)channel;
+    (UNUSED)msg_id;
+
+    struct recv_buffer *res = NULL;
+    return res;
+}
+
+/* ========================== *
+ * Packet
+ * ========================== */
+
+INTERNAL struct packet *host_channel_packet_alloc(struct host_channel *channel, b32 is_reliable)
+{
+    struct host *host = channel->host;
+    struct packet *packet = NULL;
+    if (host->first_free_packet) {
+        packet = host->first_free_packet;
+        host->first_free_packet = packet->next;
+    } else {
+        packet = arena_push(&host->packet_arena, struct packet);
+    }
+    MEMZERO_STRUCT(packet);
+
+    if (is_reliable) {
+        if (channel->last_reliable_packet) {
+            channel->last_reliable_packet->next = packet;
+        } else {
+            channel->first_reliable_packet = packet;
+        }
+        channel->last_reliable_packet = packet;
+    } else {
+        if (channel->last_unreliable_packet) {
+            channel->last_unreliable_packet->next = packet;
+        } else {
+            channel->first_unreliable_packet = packet;
+        }
+        channel->last_unreliable_packet = packet;
+    }
+    return packet;
+}
+
+/* ========================== *
+ * Recv buffer
+ * ========================== */
+
+INTERNAL struct recv_buffer *recv_buffer_alloc(struct host_channel *channel, u64 msg_id, u64 chunk_count)
+{
+    (UNUSED)channel;
+    (UNUSED)msg_id;
+    (UNUSED)chunk_count;
+
+    struct recv_buffer *res = NULL;
+    return res;
+}
+
+INTERNAL b32 recv_buffer_is_chunk_filled(struct recv_buffer *rb, u64 chunk_id)
+{
+    (UNUSED)rb;
+    (UNUSED)chunk_id;
+
+    return false;
+}
+
+INTERNAL void recv_buffer_set_chunk_received(struct recv_buffer *rb, u64 chunk_id)
+{
+    (UNUSED)rb;
+    (UNUSED)chunk_id;
+}
+
 /* ========================== *
  * Queue
  * ========================== */
 
 INTERNAL struct host_cmd *host_cmd_alloc_and_append(struct host *host)
 {
-    struct host_cmd *cmd = NULL;
-    if (host->first_free_cmd) {
-        cmd = host->first_free_cmd;
-        host->first_free_cmd = cmd->next_free;
-    } else {
-        cmd = arena_push(&host->arena, struct host_cmd);
-    }
-    MEMZERO_STRUCT(cmd);
+    struct host_cmd *cmd = arena_push_zero(&host->cmd_arena, struct host_cmd);
     if (host->last_cmd) {
         host->last_cmd->next = cmd;
     } else {
@@ -126,24 +246,29 @@ INTERNAL struct host_cmd *host_cmd_alloc_and_append(struct host *host)
     return cmd;
 }
 
-void host_queue_connect_to_address(struct host *host, struct host_address_desc host_address_desc)
+void host_queue_connect_to_address(struct host *host, struct sock_address connect_address)
 {
-    struct sock_address_desc sock_address_desc = sock_address_desc_from_host_address_desc(host_address_desc);
-    struct sock_address address = sock_address_from_desc(sock_address_desc);
-    struct channel *channel = channel_from_address(host, address);
+    struct host_channel *channel = host_channel_from_address(host, connect_address);
     if (!channel->valid) {
-        channel = channel_alloc(host, address);
+        channel = host_channel_alloc(host, connect_address);
     }
 }
 
 void host_queue_disconnect(struct host *host, struct host_channel_id channel_id)
 {
+    (UNUSED)host;
+    (UNUSED)channel_id;
+
     struct host_cmd *cmd = host_cmd_alloc_and_append(host);
     cmd->kind = HOST_CMD_KIND_DISCONNECT;
 }
 
 void host_queue_write(struct host *host, struct host_channel_id channel_id, struct string msg)
 {
+    (UNUSED)host;
+    (UNUSED)channel_id;
+    (UNUSED)msg;
+
     struct host_cmd *cmd = host_cmd_alloc_and_append(host);
     cmd->kind = HOST_CMD_KIND_WRITE;
 }
@@ -152,111 +277,143 @@ void host_queue_write(struct host *host, struct host_channel_id channel_id, stru
  * Update
  * ========================== */
 
+INTERNAL struct host_queued_event *host_queued_event_alloc_and_append(struct host *host)
+{
+    struct host_queued_event *qe = arena_push_zero(&host->queued_event_arena, struct host_queued_event);
+    if (host->last_queued_event) {
+        host->last_queued_event->next = qe;
+    } else {
+        host->first_queued_event = qe;
+    }
+    host->last_queued_event = qe;
+    ++host->num_queued_events;
+    return qe;
+}
+
 void host_update(struct host *host)
 {
     struct temp_arena scratch = scratch_begin_no_conflict();
 
-    struct socket *sock = &host->sock;
+    i64 now_ns = sys_time_ns();
+
+    struct sock *sock = &host->sock;
     struct string read_buff = ZI;
-    read_buff.len = KILOBYTE(64);
+    read_buff.len = PACKET_DATA_MAX_LEN;
     read_buff.text = arena_push_array(scratch.arena, u8, read_buff.len);
 
     /* Read socket */
     while (true) {
         struct sock_read_result res = sock_read(sock, read_buff);
         if (res.valid) {
-            struct string data = res.data;
+            struct string sock_data = res.data;
             struct sock_address address = res.address;
-            struct byte_reader br = br_from_buffer(data);
+            struct byte_reader br = br_from_buffer(sock_data);
             u32 magic = br_read_u32(&br);
             if (magic == PACKET_MAGIC) {
                 /* TODO: Combine kind byte with flags byte */
-                struct host_channel *channel = host_channel_from_sock_address(host, address);
+                struct host_channel *channel = host_channel_from_address(host, address);
                 enum packet_kind packet_kind = br_read_i8(&br);
                 u8 packet_flags = br_read_u8(&br);
-                u64 packet_id = br_read_var_uint(&br);
-                u64 packet_reliable_id = 0;
-                if (packet_flags & PACKET_FLAG_RELIABLE) {
-                    packet_reliable_id = br_read_var_uint(&br);
+
+                u64 their_acked_seq = br_read_var_uint(&br);
+                if (their_acked_seq > channel->their_acked_seq) {
+                    channel->their_acked_seq = their_acked_seq;
                 }
-                switch (packet_kind) {
-                    case PACKET_KIND_TRY_CONNECT:
-                    {
-                        /* A foreign host is trying to connect to us */
-                        if (!channel->valid) {
-                            channel = channel_alloc(host, address);
-                        }
-                    } break;
 
-                    case PACKET_KIND_CONNECT_SUCCESS:
-                    {
-                        /* We successfully connected to a foreign host and they are ready to receive messages */
-                        if (channel->valid && !channel->connected) {
-                            struct host_queued_event *queued_event = queued_event_alloc_and_append(host);
-                            queued_event->kind = HOST_EVENT_KIND_CHANNEL_OPENED;
-                            queued_event->channel_id = channel->id;
-                            channel->connected = true;
-                        }
-                    } break;
+                b32 should_process_packet = false;
+                if (packet_flags & PACKET_FLAG_RELIABLE) {
+                    u64 packet_seq = br_read_var_uint(&br);
+                    if (packet_seq == channel->our_acked_seq + 1) {
+                        channel->our_acked_seq = packet_seq;
+                        should_process_packet = true;
+                    }
+                } else {
+                    should_process_packet = true;
+                }
 
-                    case PACKET_KIND_DISCONNECT:
-                    {
-                        /* A foreign host disconnected from us */
-                        if (channel->valid) {
-                            struct host_queued_event *queued_event = queued_event_alloc_and_append(host);
-                            queued_event->kind = HOST_EVENT_KIND_CHANNEL_CLOSED;
-                            queued_event->channel_id = channel->id;
-                            channel_release(channel);
-                        }
+                if (should_process_packet) {
+                    switch (packet_kind) {
+                        case PACKET_KIND_TRY_CONNECT:
+                        {
+                            /* A foreign host is trying to connect to us */
+                            if (!channel->valid) {
+                                /* TODO: Verify that some per-host uuid isn't
+                                 * present in a rolling window to prevent reconnects right after a disconnect? */
+                                channel = host_channel_alloc(host, address);
+                            }
+                        } break;
 
-                    } break;
+                        case PACKET_KIND_CONNECT_SUCCESS:
+                        {
+                            /* We successfully connected to a foreign host and they are ready to receive messages */
+                            if (channel->valid && !channel->connected) {
+                                struct host_queued_event *queued_event = host_queued_event_alloc_and_append(host);
+                                queued_event->event.kind = HOST_EVENT_KIND_CHANNEL_OPENED;
+                                queued_event->event.channel_id = channel->id;
+                                channel->connected = true;
+                            }
+                        } break;
 
-                    case PACKET_KIND_MSG_CHUNK:
-                    {
-                        /* Packet is chunk <chunk_id> out of <chunk_count> belonging to message <msg_id> */
-                        u64 msg_id = br_read_var_uint(&br);
-                        u64 chunk_id = br_read_var_uint(&br);
-                        u64 chunk_count = br_read_var_uint(&br);
-                        u64 data_len = ((chunk_id + 1) == chunk_count) ? br_read_u8(&br) : PACKET_CHUNK_MAX_LEN;
+                        case PACKET_KIND_DISCONNECT:
+                        {
+                            /* A foreign host disconnected from us */
+                            if (channel->valid) {
+                                struct host_queued_event *queued_event = host_queued_event_alloc_and_append(host);
+                                queued_event->event.kind = HOST_EVENT_KIND_CHANNEL_CLOSED;
+                                queued_event->event.channel_id = channel->id;
+                                host_channel_release(channel);
+                            }
 
-                        struct msg_buffer *msg_buff = channel_get_msg_buffer(channel, msg_id);
-                        if (!msg_buff) {
-                            msg_buff = channel_msg_buffer_alloc(channel, chunk_count);
-                        }
+                        } break;
 
-                        if (chunk_count == msg_buff->chunk_count && chunk_id < chunk_count) {
-                            struct msg_chunk *chunk = &msg_buff->chunks[chunk_id];
-                            if (!chunk->filled) {
-                                u8 *data = br_seek(&br, data_len);
-                                if (data) {
-                                    MEMCPY(chunk->data, data, data_len);
-                                    chunk->data_len = data_len;
-                                    chunk->filled = true;
-                                    ++msg_buff->filled_chunks;
-                                    msg_buff->last_touch = now;
-                                    if (msg_buff->filled_chunks == chunk_count) {
-                                        /* All chunks filled, message has finished assembling */
-                                        /* TODO: Message ordering */
-                                        struct host_queued_event *queued_event = queued_event_alloc_and_append(host);
-                                        struct string data = ZI;
-                                        data.text = arena_push_array(&host->queued_event_arena, u8, chunk_count * PACKET_CHUNK_MAX_LEN);
-                                        for (u64 i = 0; i < chunk_count; ++i) {
-                                            struct msg_chunk *filled_chunk = &msg_buff->chunks[i];
-                                            u64 len = filled_chunk->data_len;
-                                            MEMCPY(data.text + data.len, filled_chunk->data, len);
-                                            data.len += len;
+                        case PACKET_KIND_MSG_CHUNK:
+                        {
+                            /* Packet is chunk <chunk_id> out of <chunk_count> belonging to message <msg_id> */
+                            u64 msg_id = br_read_var_uint(&br);
+                            u64 chunk_id = br_read_var_uint(&br);
+                            u64 chunk_count = br_read_var_uint(&br);
+
+                            b32 is_last_chunk = (chunk_id + 1) == chunk_count;
+                            u64 data_len = is_last_chunk ? (br_read_u8(&br) + 1) : PACKET_CHUNK_MAX_LEN;
+
+                            struct recv_buffer *recv_buff = host_channel_get_recv_buffer(channel, msg_id);
+                            if (!recv_buff) {
+                                recv_buff = recv_buffer_alloc(channel, msg_id, chunk_count);
+                            }
+
+                            if (chunk_count == recv_buff->num_chunks_total && chunk_id < chunk_count) {
+                                if (!recv_buffer_is_chunk_filled(recv_buff, chunk_id)) {
+                                    u8 *src = br_seek(&br, data_len);
+                                    if (src) {
+                                        u8 *dst = &recv_buff->data[chunk_id * PACKET_CHUNK_MAX_LEN];
+                                        MEMCPY(dst, src, data_len);
+                                        if (is_last_chunk) {
+                                            recv_buff->last_chunk_len = data_len;
+                                        }
+                                        recv_buffer_set_chunk_received(recv_buff, chunk_id);
+                                        ++recv_buff->num_chunks_received;
+                                        recv_buff->touched_ns = now_ns;
+                                        if (recv_buff->num_chunks_received == chunk_count) {
+                                            /* All chunks filled, message has finished assembling */
+                                            /* TODO: Message ordering */
+                                            struct host_queued_event *queued_event = host_queued_event_alloc_and_append(host);
+                                            struct string data = ZI;
+                                            data.len = ((chunk_count - 1) * PACKET_CHUNK_MAX_LEN) + recv_buff->last_chunk_len;
+                                            data.text = arena_push_array(&host->queued_event_arena, u8, data.len);
+                                            MEMCPY(data.text, recv_buff->data, data.len);
+                                            queued_event->event.kind = HOST_EVENT_KIND_MSG;
+                                            queued_event->event.msg = data;
+                                            queued_event->event.channel_id = channel->id;
                                         }
-                                        queued_event->kind = HOST_EVENT_KIND_MSG;
-                                        queued_event->msg_data = data;
-                                        queued_event->channel_id = channel->id;
                                     }
                                 }
                             }
-                        }
-                    } break;
+                        } break;
 
-                    default: break;
+                        default: break;
+                    }
                 }
+
             }
         } else {
             break;
@@ -265,66 +422,93 @@ void host_update(struct host *host)
 
     /* Release expired msg buffers */
 
-    /* Try connecting to unconnected hosts */
-    for (u64 i = 0; i < host->channels; ++i) {
-        struct channel *channel = &host->channels[i];
-        if (channel->valid && !channel->connected) {
-            struct host_cmd *cmd = host_cmd_alloc_and_append(host);
-            cmd->kind = HOST_CMD_KIND_TRY_CONNECT;
-            cmd->channel_id = channel->id;
+    /* Update channels */
+    for (u64 i = 0; i < host->channels_reserved; ++i) {
+        struct host_channel *channel = &host->channels[i];
+        if (channel->valid) {
+            /* Send / resend handshake if not connected */
+            if (!channel->connected) {
+                struct host_cmd *cmd = host_cmd_alloc_and_append(host);
+                cmd->kind = HOST_CMD_KIND_TRY_CONNECT;
+                cmd->channel_id = channel->id;
+            }
+            /* Release acked reliable packets */
+            {
+                u64 acked_seq = channel->their_acked_seq;
+                struct packet *packet = channel->first_reliable_packet;
+                while (packet) {
+                    struct packet *next = packet->next;
+                    u64 seq = packet->seq;
+                    if (seq < acked_seq) {
+                        packet->next = host->first_free_packet;
+                        host->first_free_packet = packet;
+                        channel->first_reliable_packet = next;
+                    } else {
+                        break;
+                    }
+                    packet = next;
+                }
+                if (channel->first_reliable_packet == NULL) {
+                    channel->last_reliable_packet = NULL;
+                }
+            }
         }
     }
 
-    /* Release un
-
     /* Process cmds */
+    /* TODO: Unreliable packets don't need to be allocated into unreliable packet queue, should just send them and forget */
     for (struct host_cmd *cmd = host->first_cmd; cmd; cmd = cmd->next) {
-        struct host_channel *channel = host_channel_from_id(host, cmd->channel_id);
-        if (channel->valid) {
-            enum host_cmd_kind kind = cmd->kind;
-            struct sock_address address = channel->sock_address;
-
+        struct temp_arena temp = arena_temp_begin(scratch.arena);
+        enum host_cmd_kind kind = cmd->kind;
+        struct host_channel_id channel_id = cmd->channel_id;
+        struct host_channel_list channels = host_channels_from_id(temp.arena, host, channel_id);
+        for (struct host_channel_node *node = channels.first; node; node = node->next) {
+            struct host_channel *channel = node->channel;
             switch (kind) {
                 case HOST_CMD_KIND_TRY_CONNECT:
                 {
-                    struct packet *packet = host_packet_alloc(host, address, false);
+                    u8 packet_flags = 0;
+                    struct packet *packet = host_channel_packet_alloc(channel, false);
                     struct byte_writer bw = bw_from_buffer(STRING_FROM_ARRAY(packet->data));
                     bw_write_i8(&bw, PACKET_KIND_TRY_CONNECT);
                     bw_write_u8(&bw, packet_flags);
-                    bw_write_var_uint(&bw, packet->id);
-                    bw_write_var_uint(&bw, packet->reliable_id);
+                    bw_write_var_uint(&bw, channel->our_acked_seq);
                     packet->data_len = bw_pos(&bw);
                 } break;
 
                 case HOST_CMD_KIND_CONNECT_SUCCESS:
                 {
-                    struct packet *packet = host_packet_alloc(host, address, false);
+                    u8 packet_flags = 0;
+                    struct packet *packet = host_channel_packet_alloc(channel, false);
                     struct byte_writer bw = bw_from_buffer(STRING_FROM_ARRAY(packet->data));
                     bw_write_i8(&bw, PACKET_KIND_CONNECT_SUCCESS);
                     bw_write_u8(&bw, packet_flags);
-                    bw_write_var_uint(&bw, packet->id);
-                    bw_write_var_uint(&bw, packet->reliable_id);
+                    bw_write_var_uint(&bw, channel->our_acked_seq);
                     packet->data_len = bw_pos(&bw);
                 } break;
 
                 case HOST_CMD_KIND_DISCONNECT:
                 {
-                    struct packet *packet = host_packet_alloc(host, address, false);
+                    u8 packet_flags = 0;
+                    struct packet *packet = host_channel_packet_alloc(channel, false);
                     struct byte_writer bw = bw_from_buffer(STRING_FROM_ARRAY(packet->data));
                     bw_write_i8(&bw, PACKET_KIND_DISCONNECT);
                     bw_write_u8(&bw, packet_flags);
-                    bw_write_var_uint(&bw, packet->id);
+                    bw_write_var_uint(&bw, channel->our_acked_seq);
                     packet->data_len = bw_pos(&bw);
                 } break;
 
                 case HOST_CMD_KIND_WRITE:
                 {
-                    b32 is_reliable = packet_flags & HOST_WRITE_FLAG_RELIABLE;
-                    struct string msg = cmd->msg;
+                    b32 is_reliable = cmd->write_reliable;
+                    u8 packet_flags = (is_reliable * PACKET_FLAG_RELIABLE);
+                    struct string msg = cmd->write_msg;
+
                     u64 chunk_count = 0;
                     if (msg.len > 0) {
-                        chunk_count = ((msg.len - 1) / PACKET_CHUNK_MAX_LEN) + 1
+                        chunk_count = (msg.len - 1) / PACKET_CHUNK_MAX_LEN;
                     }
+                    chunk_count += 1;
 
                     for (u64 i = 0; i < chunk_count; ++i) {
                         u64 data_len = PACKET_CHUNK_MAX_LEN;
@@ -333,16 +517,17 @@ void host_update(struct host *host)
                             data_len = msg.len % PACKET_CHUNK_MAX_LEN;
                         }
                         u8 *data = msg.text + (i * PACKET_CHUNK_MAX_LEN);
-                        struct packet *packet = host_packet_alloc(host, address, is_reliable);
+                        struct packet *packet = host_channel_packet_alloc(channel, is_reliable);
                         struct byte_writer bw = bw_from_buffer(STRING_FROM_ARRAY(packet->data));
                         bw_write_i8(&bw, PACKET_KIND_MSG_CHUNK);
                         bw_write_u8(&bw, packet_flags);
-                        bw_write_var_uint(&bw, packet->id);
+                        bw_write_var_uint(&bw, channel->our_acked_seq);
                         if (is_reliable) {
-                            bw_write_var_uint(&bw, packet->reliable_id);
+                            bw_write_var_uint(&bw, packet->seq);
                         }
                         if (is_last_chunk) {
-                            bw_write_u8(&bw, data_len);
+                            /* FIXME: Ensure data_len can never be 0 */
+                            bw_write_u8(&bw, data_len - 1);
                         }
                         bw_write_buffer(&bw, STRING(data_len, data));
                         packet->data_len = bw_pos(&bw);
@@ -352,24 +537,35 @@ void host_update(struct host *host)
                 default: break;
             }
         }
+        arena_temp_end(temp);
     }
 
-    /* Send packets */
-    for (struct packet *packet = host->first_packet; packet; packet = packet->next) {
-        struct sock_address address = packet->address;
-        sock_write(sock, address, STRING(packet->data_len, packet->data));
+    /* Process packets */
+    /* TODO: Aggregate small packets */
+    for (u64 i = 0; i < host->channels_reserved; ++i) {
+        struct host_channel *channel = &host->channels[i];
+        struct sock_address address = channel->address;
+        /* Send unreliable packets to channel */
+        for (struct packet *packet = channel->first_unreliable_packet; packet; packet = packet->next) {
+            sock_write(sock, address, STRING(packet->data_len, packet->data));
+        }
+        /* Send un-acked reliable packets to channel */
+        for (struct packet *packet = channel->first_reliable_packet; packet; packet = packet->next) {
+            sock_write(sock, address, STRING(packet->data_len, packet->data));
+        }
+        /* Release unreliable packets */
+        if (channel->first_unreliable_packet) {
+            host->first_free_packet = channel->first_unreliable_packet;
+            channel->last_unreliable_packet->next = host->first_free_packet;
+            channel->first_unreliable_packet = NULL;
+            channel->last_unreliable_packet = NULL;
+        }
     }
 
-    /* Reset packets */
-    host->first_packet = NULL;
-    host->last_packet = NULL;
-    host->first_free_packet = NULL;
-    arena_reset(&host->packet_arena);
 
     /* Reset cmds */
     host->first_cmd = NULL;
     host->last_cmd = NULL;
-    host->first_free_cmd = NULL;
     arena_reset(&host->cmd_arena);
 
     scratch_end(scratch);
@@ -388,17 +584,20 @@ struct host_event_array host_pop_events(struct arena *arena, struct host *host)
     u64 i = 0;
     for (struct host_queued_event *qe = host->first_queued_event; qe; qe = qe->next) {
         struct host_event *dest = &res.events[i];
-        *dest = (struct host_event) {
-            .kind = qe->kind,
-            .msg = qe->msg
-        };
+        *dest = qe->event;
+        struct string src_msg = qe->event.msg;
+        if (src_msg.len > 0) {
+            dest->msg.text = arena_push_array(arena, u8, src_msg.len);
+            MEMCPY(dest->msg.text, src_msg.text, src_msg.len);
+        }
         ++i;
     }
 
     /* Reset queued events */
-    hust->num_queued_events = 0;
+    host->num_queued_events = 0;
     host->first_queued_event = NULL;
     host->last_queued_event = NULL;
-    host->first_free_queued_event = NULL;
     arena_reset(&host->queued_event_arena);
+
+    return res;
 }
diff --git a/src/host.h b/src/host.h
index 68d4667c..e0231e67 100644
--- a/src/host.h
+++ b/src/host.h
@@ -1,4 +1,124 @@
 #ifndef HOST_H
 #define HOST_H
 
+#include "sock.h"
+
+#define HOST_CHANNEL_ID_NIL (struct host_channel_id) { .gen = 0, .idx = 0 }
+#define HOST_CHANNEL_ID_ALL (struct host_channel_id) { .gen = U32_MAX, .idx = U32_MAX }
+
+struct packet;
+
+enum host_cmd_kind {
+    HOST_CMD_KIND_NONE,
+
+    HOST_CMD_KIND_TRY_CONNECT,
+    HOST_CMD_KIND_CONNECT_SUCCESS,
+    HOST_CMD_KIND_DISCONNECT,
+    HOST_CMD_KIND_WRITE
+};
+
+enum host_event_kind {
+    HOST_EVENT_KIND_NONE,
+
+    HOST_EVENT_KIND_CHANNEL_OPENED,
+    HOST_EVENT_KIND_CHANNEL_CLOSED,
+    HOST_EVENT_KIND_MSG
+};
+
+struct host_cmd {
+    enum host_cmd_kind kind;
+    struct host_channel_id channel_id;
+
+    b32 write_reliable;
+    struct string write_msg;
+
+    struct host_cmd *next;
+};
+
+struct host_event {
+    enum host_event_kind kind;
+    struct host_channel_id channel_id;
+    struct string msg;
+};
+
+struct host_event_array {
+    struct host_event *events;
+    u64 count;
+};
+
+struct host {
+    struct sock sock;
+
+    struct arena cmd_arena;
+    struct host_cmd *first_cmd;
+    struct host_cmd *last_cmd;
+    struct host_cmd *first_free_cmd;
+
+    struct arena queued_event_arena;
+    struct host_queued_event *first_queued_event;
+    struct host_queued_event *last_queued_event;
+    u64 num_queued_events;
+
+    struct arena packet_arena;
+    struct packet *first_free_packet;
+
+    struct arena channels_arena;
+    struct host_channel *channels;
+    u64 channels_reserved;
+};
+
+/* ========================== *
+ * Startup
+ * ========================== */
+
+struct host_startup_receipt { i32 _; };
+struct host_startup_receipt host_startup(struct sock_startup_receipt *sock_sr);
+
+/* ========================== *
+ * Host
+ * ========================== */
+
+struct host host_alloc(struct sock_address bind_address);
+
+void host_release(struct host *host);
+
+/* ========================== *
+ * Queue
+ * ========================== */
+
+void host_queue_connect_to_address(struct host *host, struct sock_address connect_address);
+
+void host_queue_disconnect(struct host *host, struct host_channel_id channel_id);
+
+void host_queue_write(struct host *host, struct host_channel_id channel_id, struct string msg);
+
+/* ========================== *
+ * Update
+ * ========================== */
+
+void host_update(struct host *host);
+
+/* ========================== *
+ * Events
+ * ========================== */
+
+struct host_event_array host_pop_events(struct arena *arena, struct host *host);
+
+
+
+
+
+
+
+
+
+
+
+INLINE b32 host_channel_id_is_nil(struct host_channel_id id)
+{
+    return id.gen == 0 && id.idx == 0;
+}
+
+
+
 #endif
diff --git a/src/sock.h b/src/sock.h
index 538960e4..219e5876 100644
--- a/src/sock.h
+++ b/src/sock.h
@@ -1,6 +1,60 @@
 #ifndef SOCK_H
 #define SOCK_H
 
+
+
+
+#if 1
+
+
+
+enum sock_flag {
+    SOCK_FLAG_NONE = 0,
+    SOCK_FLAG_NON_BLOCKING = (1 << 0)
+};
+
+struct sock {
+    i32 _;
+};
+
+enum sock_address_kind {
+    SOCK_ADDRESS_KIND_NONE,
+    SOCK_ADDRESS_KIND_UNBINDABLE,
+
+    /* Network addresses */
+    SOCK_ADDRESS_KIND_ANY_LOCAL_INTERFACE,
+    SOCK_ADDRESS_KIND_RAW
+};
+
+struct sock_address {
+    enum sock_address_kind kind;
+    u8 ip[16];
+    u16 port;
+};
+
+struct sock_read_result {
+    b32 valid;
+    struct sock_address address;
+    struct string data;
+};
+
+struct sock_startup_receipt { i32 _; };
+struct sock_startup_receipt sock_startup(void);
+
+struct sock_address sock_address_from_string(struct string str);
+struct sock_address sock_address_from_any_local_interface_with_port(u16 port);
+struct sock_address sock_address_from_any_local_interface_with_dynamic_port(void);
+struct sock_address sock_address_unbindable(void);
+
+struct sock sock_alloc(struct sock_address bind_address, u32 sock_flags);
+void sock_release(struct sock *sock);
+struct sock_read_result sock_read(struct sock *sock, struct string read_buff);
+void sock_write(struct sock *sock, struct sock_address address, struct string data);
+
+
+
+#else
+
 #define SOCK_IP_ANY_INTERFACE CPPCOMPAT_INITLIST_TYPE(struct sock_ip) { 0 }
 #define SOCK_PORT_DYNAMIC (0)
 
@@ -58,5 +112,6 @@ void sock_write(struct sock *sock, struct sock_address address, struct string ms
 void sock_testsend(void);
 
 void sock_testrecv(void);
+#endif
 
 #endif
diff --git a/src/sock_win32.c b/src/sock_win32.c
index bc0a0474..5b7591b0 100644
--- a/src/sock_win32.c
+++ b/src/sock_win32.c
@@ -1,3 +1,117 @@
+#if 1
+
+
+#include "sock.h"
+#include "sys.h"
+#include "log.h"
+#include "arena.h"
+#include "scratch.h"
+
+#include <WinSock2.h>
+#include <WS2tcpip.h>
+
+#pragma comment(lib, "ws2_32.lib")
+
+//#define MAX_IP_STR_LEN 46
+
+struct sock_startup_receipt sock_startup(void)
+{
+    WSADATA wsa_data;
+    /* Startup winsock */
+    WSAStartup(MAKEWORD(2, 2), &wsa_data);
+    return (struct sock_startup_receipt) { 0 };
+}
+
+struct sock_address sock_address_from_string(struct string str)
+{
+    (UNUSED)str;
+
+    struct sock_address res = ZI;
+
+#if 0
+    struct addrinfo *servinfo;
+
+    struct addrinfo hints = ZI;
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_socktype = SOCK_DGRAM;
+    hints.ai_flags = AI_PASSIVE;
+
+    status = getaddrinfo(NULL, "3490", &hints, &servinfo)
+#endif
+
+    return res;
+}
+
+struct sock_address sock_address_from_any_local_interface_with_port(u16 port)
+{
+    (UNUSED)port;
+
+    struct sock_address res = ZI;
+    return res;
+}
+
+struct sock_address sock_address_from_any_local_interface_with_dynamic_port(void)
+{
+    struct sock_address res = ZI;
+    return res;
+}
+
+struct sock_address sock_address_unbindable(void)
+{
+    struct sock_address res = ZI;
+    return res;
+}
+
+struct sock sock_alloc(struct sock_address bind_address, u32 sock_flags)
+{
+    (UNUSED)bind_address;
+    (UNUSED)sock_flags;
+
+    struct sock sock = ZI;
+
+
+
+    return sock;
+}
+
+void sock_release(struct sock *sock)
+{
+    (UNUSED)sock;
+}
+
+struct sock_read_result sock_read(struct sock *sock, struct string read_buff)
+{
+    (UNUSED)sock;
+    (UNUSED)read_buff;
+
+    struct sock_read_result res = ZI;
+    return res;
+}
+
+void sock_write(struct sock *sock, struct sock_address address, struct string data)
+{
+    (UNUSED)sock;
+    (UNUSED)address;
+    (UNUSED)data;
+}
+
+
+
+
+
+
+
+
+
+
+
+
+
+#else
+
+
+
+
 #include "sock.h"
 #include "sys.h"
 #include "log.h"
@@ -492,3 +606,6 @@ void sock_testrecv(void)
     closesocket(sock);
     WSACleanup();
 }
+
+
+#endif
diff --git a/src/user.c b/src/user.c
index a7880acf..a63cff2e 100644
--- a/src/user.c
+++ b/src/user.c
@@ -20,6 +20,7 @@
 #include "rng.h"
 #include "log.h"
 #include "sock.h"
+#include "host.h"
 
 struct bind_state {
     b32 is_held;                    /* Is this bind held down this frame */
@@ -42,6 +43,8 @@ GLOBAL struct {
 
     struct sys_window *window;
 
+    struct host host;
+
     /* Render targets */
     struct renderer_texture final_texture;
     struct renderer_texture world_texture;
@@ -137,7 +140,7 @@ struct user_startup_receipt user_startup(struct work_startup_receipt *work_sr,
                                          struct game_startup_receipt *game_sr,
                                          struct asset_cache_startup_receipt *asset_cache_sr,
                                          struct mixer_startup_receipt *mixer_sr,
-                                         struct sock_startup_receipt *sock_sr,
+                                         struct host_startup_receipt *host_sr,
                                          struct sys_window *window)
 {
     (UNUSED)work_sr;
@@ -148,14 +151,14 @@ struct user_startup_receipt user_startup(struct work_startup_receipt *work_sr,
     (UNUSED)game_sr;
     (UNUSED)asset_cache_sr;
     (UNUSED)mixer_sr;
-    (UNUSED)sock_sr;
+    (UNUSED)host_sr;
 
     G.arena = arena_alloc(GIGABYTE(64));
     G.sys_events_mutex = sys_mutex_alloc();
     G.sys_events_arena = arena_alloc(GIGABYTE(64));
     world_alloc(&G.world);
 
-    struct net_address_desc bind_addr = NET_ADDRESS_DESC_ALL_LOCAL_INTERFACES(NET_PORT_DYNAMIC);
+    struct sock_address bind_addr = sock_address_from_any_local_interface_with_dynamic_port();
     G.host = host_alloc(bind_addr);
 
     G.world_to_ui_xf = XFORM_IDENT;
@@ -215,6 +218,7 @@ INTERNAL SYS_WINDOW_EVENT_CALLBACK_FUNC_DEF(window_event_callback, event)
  * Game -> user communication
  * ========================== */
 
+#if 0
 INTERNAL struct blend_tick *blend_tick_alloc(void)
 {
     struct blend_tick *bt = NULL;
@@ -361,6 +365,7 @@ INTERNAL struct interp_ticks pull_ticks(i64 blend_time_ns)
         .to_tick = to_tick
     };
 }
+#endif
 
 /* ========================== *
  * Debug draw
@@ -455,7 +460,17 @@ INTERNAL SORT_COMPARE_FUNC_DEF(entity_draw_order_cmp, arg_a, arg_b, udata)
 
 
 
-
+INTERNAL void queue_game_cmd(struct arena *arena, struct game_cmd_list *list, struct game_cmd src)
+{
+    struct game_cmd *cmd = arena_push(arena, struct game_cmd);
+    *cmd = src;
+    if (list->last) {
+        list->last->next = cmd;
+    } else {
+        list->first = cmd;
+    }
+    list->last = cmd;
+}
 
 
 
@@ -588,7 +603,7 @@ INTERNAL void user_update(void)
 
     struct game_event_list game_events = ZI;
     {
-        struct host_events_array = host_pop_events(scratch.arena, G.host);
+        struct host_event_array host_events = host_pop_events(scratch.arena, &G.host);
         game_events_from_host_events(scratch.arena, host_events, &game_events);
     }
 
@@ -603,14 +618,13 @@ INTERNAL void user_update(void)
         static f64 last_try_connect = 0;
         f64 now = SECONDS_FROM_NS(sys_time_ns());
         if (last_try_connect == 0 || (now - last_try_connect) > 5) {
-            struct host_address_desc connect_addr = host_address_desc_from_string(LIT("127.0.0.1:12345"));
-            host_connect_to_address(G.host, connect_addr);
+            struct sock_address connect_addr = sock_address_from_string(LIT("127.0.0.1:12345"));
+            host_queue_connect_to_address(&G.host, connect_addr);
             last_try_connect = now;
         }
 
-        for (u64 i = 0; i < game_events.count; ++i) {
-            struct game_event event = game_events.events[i];
-            enum game_event_kind kind = event.kind;
+        for (struct game_event *event = game_events.first; event; event = event->next) {
+            enum game_event_kind kind = event->kind;
 
             switch (kind) {
                 case GAME_EVENT_KIND_CONNECT:
@@ -623,10 +637,10 @@ INTERNAL void user_update(void)
                     last_try_connect = 0;
                 } break;
 
-                case GAME_EVENT_KIND_SNAPSHOT:
+                case GAME_EVENT_KIND_SNAPSHOT_FULL:
                 {
-                    struct string data = event.data;
-                    game_tick_from_string(&G.world, data);
+                    struct string snapshot_data = event->snapshot_data;
+                    game_tick_from_string(snapshot_data, &G.world);
                 } break;
 
                 default: break;
@@ -1656,17 +1670,13 @@ INTERNAL void user_update(void)
     {
         struct temp_arena temp = arena_temp_begin(scratch.arena);
 
-        struct string cmds_str = game_string_from_cmds(temp.arena, game_cmds_list);
-
-        struct host_msg_desc msg = ZI;
-        msg.channel = CHANNEL_ID_ALL;
-        msg.data = cmds_str;
-        host_queue_write(G.host, msg);
+        struct string cmds_str = game_string_from_cmds(temp.arena, cmd_list);
+        host_queue_write(&G.host, HOST_CHANNEL_ID_ALL, cmds_str);
 
         arena_temp_end(temp);
     }
 
-    host_update(G.host);
+    host_update(&G.host);
 
     /* ========================== *
      * Render
diff --git a/src/user.h b/src/user.h
index 08aa9ead..534c4ec8 100644
--- a/src/user.h
+++ b/src/user.h
@@ -10,7 +10,7 @@ struct draw_startup_receipt;
 struct game_startup_receipt;
 struct asset_cache_startup_receipt;
 struct mixer_startup_receipt;
-struct sock_startup_receipt;
+struct host_startup_receipt;
 
 enum user_bind_kind {
     USER_BIND_KIND_NONE,
@@ -57,7 +57,7 @@ struct user_startup_receipt user_startup(struct work_startup_receipt *work_sr,
                                          struct game_startup_receipt *game_sr,
                                          struct asset_cache_startup_receipt *asset_cache_sr,
                                          struct mixer_startup_receipt *mixer_sr,
-                                         struct sock_startup_receipt *sock_sr,
+                                         struct host_startup_receipt *host_sr,
                                          struct sys_window *window);
 
 #endif