Zcash transactions fee

Maybe its stupid question. I didnt found answer yet.

What about transactions fee in zcash? Will them be visible? In signed transaction?

If not, then how miners can sort transactions and build block?

To avoid spam in network, smaller transactions (smaller fee) should have smallest priority.

Yes, transaction fees are always transparent.

The transaction fee policy of the official software has not been decided yet. (Of course, miners are able to apply different policies, but the one coded in the official software has considerable influence.)