DO cab in Dublin accept credit cards?

Visa and Mastercard.

You might try this ap if you want to take Taxi with credit card. it is like UBER
https://ie.mytaxi.com/hailoisnowmytaxi?erid=1491068731449236204

Great information!!! We are going to be in Dublin in Sept. and the app will be so helpful.

You'll find that Uber works in Ireland as well (in/around Dublin, at least). Remember that any app-based service will use data so you'd need to be at a WiFi point or have cheap cellphone data to use it (we have T-Mobile service which give us free roaming data overseas).