LDC
On est tous des pangolins
someone told me the French rules were "having had a booster in the past 9 months" but when I checked the rule is (currently) "having had a booster within 9 month of the second vaccination", and changes will probably occur again on these. So yeah, keep checking.
Just got back from France yesterday. Had vaccination status checked when entering from the UK 10 days ago, but was never asked for any proof while there for anything, or on return. Did a passenger locator form for arrival but that was never looked at either. Mask wearing is very high though, pretty much universal apart from bars/cafes when people are eating etc.