Paris Taxis still cash only?

Things could have changed since last April (and someone will weigh in if that's the case) but this article suggests cash for your cab ride, along with a bunch more Paris taxi tips: https://www.forbes.com/sites/marcwebertobias/2018/04/19/avoid-being-overcharged-by-taxi-drivers-in-paris/#5eadc1c11fcf

It is a fixed rate — 50€ for up to four people and their luggage from CDG to Montmartre.

Last time I took a taxi to the airport, I used a card, but I don't know if all drivers can take cards.

CDG to Montmartre is a fixed rate -- €50 as Montmartre is on the Right Bank. Make sure you take an official, licensed, legitimate taxi from the taxi line at the terminal.

all cabbies are required to take cards but not all do (machine is broken yadda yadda). I would be prepared with my 50 Euro or 55 Euro but would ask before getting in if they take a card if you want to use it. If they don't, the dispatcher can put you in the next cab. We have been taking cabs in Paris for years and have almost always paid by card. Tips are not required or expected, but if they do something extra and we want to tip, we use cash for that.

Just arrived yesterday and the gauntlet of illegal taxi touts was larger than I’ve seen previously outside Terminal 2E (maybe a dozen and a half between the end of the line of private pickups and the cordons for the queue). Just follow the signs to the outside queue for the official taxis. Interestingly after the driver looked at my hotel address he said “55 Euro, flat rate”. I knew the rate but I’ve never had a driver announce it up front.

And that flat rate should show on the meter as you depart. No add ons unless there are more than 4 people. We once had a driver try to run the meter and we just pointed it out and he put the 55 on. But it has gone smoothly otherwise. Our cabbie last May turned back for us as I had forgotten to drop the apartment key on my way out -- I tipped well for that extra little loop back but he didn't reset the meter which he could have done.

It’s 50 to right bank addresses / and 55 to left bank .