Hi friend!

The list of api command you can see there
https://github.com/t3ran13/php-graphene-node-client/blob/master/Commands/SteemitApiMethods.php

It is easy add new to list.
The almost full list steem api methods you can see here
https://github.com/steemit/steem-js/blob/master/src/api/methods.js

BUT!!! there are broadcast comands, i made some templates for

• comment https://github.com/t3ran13/php-graphene-node-client/blob/master/Tools/ChainOperations/OpComment.php
• transfer https://github.com/t3ran13/php-graphene-node-client/blob/master/Tools/ChainOperations/OpTransfer.php
• vote https://github.com/t3ran13/php-graphene-node-client/blob/master/Tools/ChainOperations/OpVote.php
• and you can make any broadcast operations without any tamplates

There more additional examples
https://github.com/t3ran13/php-graphene-node-client/blob/debug/Debug/Test.php

PS
As i know there is no more PHP lib that can brodcast operations (like vote, transfer, comment and ect.) to blockchain except my

For working broadcast you need install some php-extensions

PS 2
You can make some prepare page on backend in PHP, but in frontand you have to use js-lib for tx making and sending to blockchain. It is secure