Are minors allowed into the cafes in amsterdam?

for instance if a minor is sitting in the cafe with his/her parents but not actually buying or smoking any products

if by cafes you mean coffee shops, no.

You must be 18 to enter coffee shops, they'll ask for your ID most times before you even enter.

Cafes, places where they sell drinks, (mostly beer and stronger, but you can get coffee and soft drinks too,) you can enter at any age when accompanied by your parents.
The age to buy drinks is still 16 for beer and wine and so on, 18 for stronger drinks.
(If you are about 15 and come in with some friends there are no problems either, but if an 10 year old they do not know comes in, he will be send out, mostly that is.)
The age for buying cigarettes is also 16 and most places have a machine that needs a card that holds your age as well as coins.

Coffee shops are something different, you need to be 18 before you can go in, before you can buy hash and so on.

Think it is ok to go into cafes with minor but going into a coffee shop where they sell weed is different .

Say you went over their with your wife / husband for a smoke , you would not be allowed to take kids under 18 into the coffee shop with you .

http://www.coffeeshop.freeuk.com/

Please read the link above .

u gotta be 18 with an i.d.