diff --git a/src/bdberl.erl b/src/bdberl.erl
index 31712df..86384fa 100644
--- a/src/bdberl.erl
+++ b/src/bdberl.erl
@@ -1,8 +1,9 @@
 %% -------------------------------------------------------------------
+%% @doc
+%% Erlang interface to BerkeleyDB.
 %%
-%% bdberl: Interface to BerkeleyDB
-%% Copyright (c) 2008 The Hive.  All rights reserved.
-%%
+%% @copyright 2008-9 The Hive.  All rights reserved.
+%% @end
 %% -------------------------------------------------------------------
 -module(bdberl).
 
@@ -47,6 +48,20 @@
 -type db_update_fun_args() :: undefined | [term()].
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Open a database file, creating it if it does not exist.
+%%
+%% @spec open(Name, Type) -> {ok, Db} | {error, Error}
+%% where
+%%    Name = string()
+%%    Type = btree | hash
+%%    Db = integer()
+%%
+%% @equiv open(Name, Type, [create])
+%% @see open/3
+%% @end
+%%--------------------------------------------------------------------
 -spec open(Name :: db_name(), Type :: db_type()) ->
     {ok, db()} | {error, integer()}.
 
@@ -54,6 +69,19 @@ open(Name, Type) ->
     open(Name, Type, [create]).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Open a database file.
+%%
+%% @spec open(Name, Type, Opts) -> {ok, Db} | {error, Error}
+%% where
+%%    Name = string()
+%%    Type = btree | hash
+%%    Opts = [atom()]
+%%    Db = integer()
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec open(Name :: db_name(), Type :: db_type(), Opts :: db_flags()) ->
     {ok, db()} | {error, integer()}.
 
@@ -73,12 +101,35 @@ open(Name, Type, Opts) ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Close a database file.
+%%
+%% @spec close(Db) -> ok | {error, Error}
+%% where
+%%    Db = integer()
+%%
+%% @equiv close(Db, [])
+%% @see close/2
+%% @end
+%%--------------------------------------------------------------------
 -spec close(Db :: db()) -> ok | db_error().
 
 close(Db) ->
     close(Db, []).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Close a database file.
+%%
+%% @spec close(Db, Opts) -> ok | {error, Error}
+%% where
+%%    Db = integer()
+%%    Opts = [atom()]
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec close(Db :: db(), Opts :: db_flags()) -> ok | db_error().
 
 close(Db, Opts) ->
@@ -93,12 +144,32 @@ close(Db, Opts) ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Begin a transaction.
+%%
+%% @spec txn_begin() -> ok | {error, Error}
+%%
+%% @equiv txn_begin([])
+%% @see txn_begin/1
+%% @end
+%%--------------------------------------------------------------------
 -spec txn_begin() -> ok | db_error().
 
 txn_begin() ->
     txn_begin([]).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Begin a transaction.
+%%
+%% @spec txn_begin(Opts) -> ok | {error, Error}
+%% where
+%%    Opts = [atom()]
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec txn_begin(Opts :: db_flags()) -> ok | db_error().
 
 txn_begin(Opts) ->
@@ -111,12 +182,32 @@ txn_begin(Opts) ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Commit a transaction.
+%%
+%% @spec txn_commit() -> ok | {error, Error}
+%%
+%% @equiv txn_commit([])
+%% @see txn_commit/1
+%% @end
+%%--------------------------------------------------------------------
 -spec txn_commit() -> ok | db_error().
 
 txn_commit() ->
     txn_commit([]).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Commit a transaction.
+%%
+%% @spec txn_commit(Opts) -> ok | {error, Error}
+%% where
+%%    Opts = [atom()]
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec txn_commit(Opts :: db_flags()) -> ok | db_error().
 
 txn_commit(Opts) ->
@@ -134,6 +225,14 @@ txn_commit(Opts) ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Abort a transaction.
+%%
+%% @spec txn_abort() -> ok | {error, Error}
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec txn_abort() -> ok | db_error().
 
 txn_abort() ->
@@ -153,12 +252,35 @@ txn_abort() ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Execute a fun inside of a transaction.
+%%
+%% @spec transaction(Fun) -> {ok, Value} | {error, Error}
+%% where
+%%    Fun = function()
+%%
+%% @equiv transaction(Fun, infinity)
+%% @see transaction/2
+%% @end
+%%--------------------------------------------------------------------
 -spec transaction(Fun :: txn_fun()) -> {ok, db_value()} | db_error().
 
 transaction(Fun) ->
     transaction(Fun, infinity).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Execute a fun inside of a transaction.
+%%
+%% @spec transaction(Fun, Retries) -> {ok, Value} | {error, Error}
+%% where
+%%    Fun = function()
+%%    Retries = infinity | integer()
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec transaction(Fun :: txn_fun(), Retries :: txn_retries()) ->
     {ok, db_value()} | {error, db_error_reason() | {transaction_failed, term()}}.
 
@@ -198,6 +320,20 @@ transaction(Fun, Retries) ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Store a value in a database file.
+%%
+%% @spec put(Db, Key, Value) -> ok | {error, Error}
+%% where
+%%    Db = integer()
+%%    Key = any()
+%%    Value = any()
+%%
+%% @equiv put(Db, Key, Value, [])
+%% @see put/4
+%% @end
+%%--------------------------------------------------------------------
 -spec put(Db :: db(), Key :: db_key(), Value :: db_value()) ->
     ok | db_error().
 
@@ -205,6 +341,19 @@ put(Db, Key, Value) ->
     put(Db, Key, Value, []).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Store a value in a database file.
+%%
+%% @spec put(Db, Key, Value, Opts) -> ok | {error, Error}
+%% where
+%%    Db = integer()
+%%    Key = any()
+%%    Value = any()
+%%    Opts = [atom()]
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec put(Db :: db(), Key :: db_key(), Value :: db_value(), Opts :: db_flags()) ->
     ok | db_error().
 
@@ -212,12 +361,43 @@ put(Db, Key, Value, Opts) ->
     do_put(?CMD_PUT, Db, Key, Value, Opts).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Store a value in a database file.
+%%
+%% @spec put_r(Db, Key, Value) -> ok
+%% where
+%%    Db = integer()
+%%    Key = any()
+%%    Value = any()
+%%
+%% @throws {error, Error}
+%%
+%% @equiv put_r(Db, Key, Value, [])
+%% @see put_r/4
+%% @end
+%%--------------------------------------------------------------------
 -spec put_r(Db :: db(), Key :: db_key(), Value :: db_value()) -> ok.
 
 put_r(Db, Key, Value) ->
     put_r(Db, Key, Value, []).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Store a value in a database file.
+%%
+%% @spec put_r(Db, Key, Value, Opts) -> ok
+%% where
+%%    Db = integer()
+%%    Key = any()
+%%    Value = any()
+%%    Opts = [atom()]
+%%
+%% @throws {error, Error}
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec put_r(Db :: db(), Key :: db_key(), Value :: db_value(), Opts :: db_flags()) -> ok.
 
 put_r(Db, Key, Value, Opts) ->
@@ -227,6 +407,20 @@ put_r(Db, Key, Value, Opts) ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Store a value in a database file.
+%%
+%% @spec put_commit(Db, Key, Value) -> ok | {error, Error}
+%% where
+%%    Db = integer()
+%%    Key = any()
+%%    Value = any()
+%%
+%% @equiv put_commit(Db, Key, Value, [])
+%% @see put_commit/4
+%% @end
+%%--------------------------------------------------------------------
 -spec put_commit(Db :: db(), Key :: db_key(), Value :: db_value()) ->
     ok | db_error().
 
@@ -234,6 +428,19 @@ put_commit(Db, Key, Value) ->
     put_commit(Db, Key, Value, []).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Store a value in a database file.
+%%
+%% @spec put_commit(Db, Key, Value, Opts) -> ok | {error, Error}
+%% where
+%%    Db = integer()
+%%    Key = any()
+%%    Value = any()
+%%    Opts = [atom()]
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec put_commit(Db :: db(), Key :: db_key(), Value :: db_value(), Opts :: db_flags()) ->
     ok | db_error().
 
@@ -241,12 +448,43 @@ put_commit(Db, Key, Value, Opts) ->
     do_put(?CMD_PUT_COMMIT, Db, Key, Value, Opts).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Store a value in a database file.
+%%
+%% @spec put_commit_r(Db, Key, Value) -> ok
+%% where
+%%    Db = integer()
+%%    Key = any()
+%%    Value = any()
+%%
+%% @throws {error, Error}
+%%
+%% @equiv put_commit_r(Db, Key, Value, [])
+%% @see put_commit_r/4
+%% @end
+%%--------------------------------------------------------------------
 -spec put_commit_r(Db :: db(), Key :: db_key(), Value :: db_value()) -> ok.
 
 put_commit_r(Db, Key, Value) ->
     put_commit_r(Db, Key, Value, []).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Store a value in a database file.
+%%
+%% @spec put_commit_r(Db, Key, Value, Opts) -> ok
+%% where
+%%    Db = integer()
+%%    Key = any()
+%%    Value = any()
+%%    Opts = [atom()]
+%%
+%% @throws {error, Error}
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec put_commit_r(Db :: db(), Key :: db_key(), Value :: db_value(), Opts :: db_flags()) -> ok.
 
 put_commit_r(Db, Key, Value, Opts) ->
@@ -256,6 +494,19 @@ put_commit_r(Db, Key, Value, Opts) ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Retrieve a value based on key.
+%%
+%% @spec get(Db, Key) -> not_found | {ok, Value} | {error, Error}
+%% where
+%%    Db = integer()
+%%    Key = term()
+%%
+%% @equiv get(Db, Key, [])
+%% @see get/3
+%% @end
+%%--------------------------------------------------------------------
 -spec get(Db :: db(), Key :: db_key()) ->
     not_found | {ok, db_ret_value()} | db_error().
 
@@ -263,6 +514,18 @@ get(Db, Key) ->
     get(Db, Key, []).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Retrieve a value based on key.
+%%
+%% @spec get(Db, Key, Opts) -> not_found | {ok, Value} | {error, Error}
+%% where
+%%    Db = integer()
+%%    Key = term()
+%%    Opts = [atom()]
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec get(Db :: db(), Key :: db_key(), Opts :: db_flags()) ->
     not_found | {ok, db_ret_value()} | db_error().
 
@@ -283,6 +546,21 @@ get(Db, Key, Opts) ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Retrieve a value based on key.
+%%
+%% @spec get_r(Db, Key) -> not_found | {ok, Value}
+%% where
+%%    Db = integer()
+%%    Key = term()
+%%
+%% @throws {error, Error}
+%%
+%% @equiv get_r(Db, Key, [])
+%% @see get_r/3
+%% @end
+%%--------------------------------------------------------------------
 -spec get_r(Db :: db(), Key :: db_key()) ->
     not_found | {ok, db_ret_value()}.
 
@@ -290,6 +568,20 @@ get_r(Db, Key) ->
     get_r(Db, Key, []).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Retrieve a value based on key.
+%%
+%% @spec get_r(Db, Key, Opts) -> not_found | {ok, Value}
+%% where
+%%    Db = integer()
+%%    Key = term()
+%%    Opts = [atom()]
+%%
+%% @throws {error, Error}
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec get_r(Db :: db(), Key :: db_key(), Opts :: db_flags()) ->
     not_found | {ok, db_ret_value()}.
 
@@ -301,6 +593,20 @@ get_r(Db, Key, Opts) ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Updates the value of a key by executing a fun.
+%%
+%% @spec update(Db, Key, Fun) -> {ok, Value} | {error, Error}
+%% where
+%%    Db = integer()
+%%    Key = term()
+%%    Fun = function()
+%%
+%% @equiv update(Db, Key, Fun, undefined)
+%% @see update/4
+%% @end
+%%--------------------------------------------------------------------
 -spec update(Db :: db(), Key :: db_key(), Fun :: db_update_fun()) ->
     {ok, db_value()} | db_error().
 
@@ -308,6 +614,19 @@ update(Db, Key, Fun) ->
     update(Db, Key, Fun, undefined).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Updates the value of a key by executing a fun.
+%%
+%% @spec update(Db, Key, Fun, Args) -> {ok, Value} | {error, Error}
+%% where
+%%    Db = integer()
+%%    Key = term()
+%%    Fun = function()
+%%    Args = any()
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec update(Db :: db(), Key :: db_key(), Fun :: db_update_fun(), Args :: db_update_fun_args()) ->
     {ok, db_value()} | db_error().
 
@@ -327,12 +646,30 @@ update(Db, Key, Fun, Args) ->
     transaction(F).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Truncates all of the open databases.
+%%
+%% @spec truncate() -> ok | {error, Error}
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec truncate() -> ok | db_error().
 
 truncate() ->
     truncate(-1).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Truncates a database.
+%%
+%% @spec truncate(Db) -> ok | {error, Error}
+%% where
+%%    Db = integer()
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec truncate(Db :: -1 | db()) -> ok | db_error().
 
 truncate(Db) ->
@@ -350,6 +687,16 @@ truncate(Db) ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Opens a cursor on a database.
+%%
+%% @spec cursor_open(Db) -> {ok, Db} | {error, Error}
+%% where
+%%    Db = integer()
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec cursor_open(Db :: db()) -> ok | db_error().
 
 cursor_open(Db) ->
@@ -363,24 +710,56 @@ cursor_open(Db) ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Returns the next cursor value.
+%%
+%% @spec cursor_next() -> not_found | {ok, Key, Value} | {error, Error}
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec cursor_next() -> {ok, db_key(), db_value()} | not_found | db_error().
 
 cursor_next() ->
     do_cursor_move(?CMD_CURSOR_NEXT).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Returns the previous cursor value.
+%%
+%% @spec cursor_prev() -> not_found | {ok, Key, Value} | {error, Error}
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec cursor_prev() -> {ok, db_key(), db_value()} | not_found | db_error().
 
 cursor_prev() ->
     do_cursor_move(?CMD_CURSOR_PREV).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Returns the current cursor value.
+%%
+%% @spec cursor_current() -> not_found | {ok, Key, Value} | {error, Error}
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec cursor_current() -> {ok, db_key(), db_value()} | not_found | db_error().
 
 cursor_current() ->
     do_cursor_move(?CMD_CURSOR_CURR).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Closes the cursor.
+%%
+%% @spec cursor_close() -> ok | {error, Error}
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec cursor_close() -> ok | db_error().
 
 cursor_close() ->
@@ -393,6 +772,16 @@ cursor_close() ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Delete a database file.
+%%
+%% @spec delete_database(Filename) -> ok | {error, Error}
+%% where
+%%    Filename = string()
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec delete_database(Filename :: db_name()) ->
     ok | db_error().
 
@@ -407,6 +796,16 @@ delete_database(Filename) ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Returns the list of directories that bdberl searches to find databases.
+%%
+%% @spec get_data_dirs() -> [DirName] | {error, Error}
+%% where
+%%    DirName = string()
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec get_data_dirs() -> [db_name(),...] | db_error().
 
 get_data_dirs() ->
@@ -433,6 +832,18 @@ get_data_dirs() ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Returns the size of the in-memory cache.
+%%
+%% @spec get_cache_size() -> {ok, Gbytes, Mbytes, NumCaches} | {error, Error}
+%% where
+%%    Gbytes = integer()
+%%    Mbytes = integer()
+%%    NumCaches = integer()
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec get_cache_size() ->
     {ok, non_neg_integer(), non_neg_integer(), non_neg_integer()} | db_error().
 
@@ -448,6 +859,16 @@ get_cache_size() ->
     end.
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Returns the transaction timeout value.
+%%
+%% @spec get_txn_timeout() -> {ok, Timeout} | {error, Error}
+%% where
+%%    Timeout = integer()
+%%
+%% @end
+%%--------------------------------------------------------------------
 -spec get_txn_timeout() -> {ok, non_neg_integer()} | db_error().
 
 get_txn_timeout() ->