diff --git a/event_loop.h b/event_loop.h
index 0903bb9..e9479d9 100644
--- a/event_loop.h
+++ b/event_loop.h
@@ -6,6 +6,7 @@
 
 #include "utarray.h"
 
+/* Ion: say what is this header about; add some comments */
 typedef struct {
   /* The type of connection (e.g. redis, client, manager, data transfer). */
   int type;
@@ -13,6 +14,7 @@ typedef struct {
   void *data;
 } event_loop_item;
 
+/* Ion: say what is the purpose of this data structure */
 typedef struct {
   /* Array of event_loop_items that hold information for connections. */
   UT_array *items;
@@ -21,6 +23,7 @@ typedef struct {
 } event_loop;
 
 /* Event loop functions. */
+/* Ion: While some of the function names are selfexplanatory, some are not; please add comments */
 void event_loop_init(event_loop *loop);
 void event_loop_free(event_loop *loop);
 int64_t event_loop_attach(event_loop *loop,
diff --git a/state/db.h b/state/db.h
index b586f9a..f43ab53 100644
--- a/state/db.h
+++ b/state/db.h
@@ -8,19 +8,23 @@ typedef struct db_conn_impl db_conn;
 /* Connect to the global system store at address and port. The last
  * parameter is an output parameter and we assume the memory is
  * allocated by the caller. */
+ /* Ion: don't we return errors? */
+ /* Ion: what about sharding? the API below assume a single instance, no? */
 void db_connect(const char *db_address,
                 int db_port,
-                const char *client_type,
+                const char *client_type, /* Ion: say what type is */
                 const char *client_addr,
                 int client_port,
                 db_conn *db);
 
 /* Attach global system store onnection to event loop. Returns the index of the
  * connection in the loop. */
+ /* Ion: what are the event loop arguments */
 int64_t db_attach(db_conn *db, event_loop *loop, int connection_type);
 
 /* This function will be called by the user if there is a new event in the
  * event loop associated with the global system store connection. */
+ /* Ion: so is db_event() an argeument in db_attach() ? */
 void db_event(db_conn *db);
 
 /* Disconnect from the global system store. */
diff --git a/state/object_table.h b/state/object_table.h
index 6b4d62e..919b56c 100644
--- a/state/object_table.h
+++ b/state/object_table.h
@@ -4,12 +4,16 @@
 typedef void (*lookup_callback)(void *);
 
 /* Register a new object with the directory. */
+/* Ion: don't we need to specify the ID of the node the object is stored on? */
+/* Ion: we should return errors, no? */
 void object_table_add(db_conn *db, unique_id object_id);
 
 /* Remove object from the directory */
+/* Ion: same as above; the node the object is stored on? errors? */
 void object_table_remove(db_conn *db, unique_id object_id);
 
 /* Look up entry from the directory */
+/* Ion: what are the arguments of the callback ? */
 void object_table_lookup(db_conn *db,
                          unique_id object_id,
                          lookup_callback callback);
diff --git a/state/redis.h b/state/redis.h
index 471044b..1edf4c1 100644
--- a/state/redis.h
+++ b/state/redis.h
@@ -6,6 +6,7 @@
 
 struct db_conn_impl {
   /* String that identifies this client type. */
+  /* Ion: say more about what the client type is */
   char *client_type;
   /* Unique ID for this client within the type. */
   int64_t client_id;
@@ -17,6 +18,7 @@ struct db_conn_impl {
   event_loop *loop;
 };
 
+/* Ion: say what the next functions are doing and what are the arguments, i.e., r and privdata */
 void object_table_fetch_addr_port(redisAsyncContext *c,
                                   void *r,
                                   void *privdata);