Short and long term gains
Gains from crypto sold within 365 days are taxed at 28%, or you can choose to add them to your other income and pay progressive rates. After 365 days, gains are exempt for residents, unless the assets are held through certain tax havens.
Swaps
Exchanging one crypto asset for another is generally not taxed at the time; the holding period and cost carry over to the new asset, and tax applies when you convert to euros.
Staking, mining and professional activity
Staking rewards and similar earnings are capital income. Mining and frequent professional trading are business income taxed under category B.
Other taxes
Crypto received as a gift or inheritance can be subject to 10% stamp duty. Keep records of purchase dates to prove holding periods.