Multitool, patches, powerlinks, at least one spare tube, pump (and none of your tiny pocket pumps, a proper big un that’ll actually inflate a tyre before nightfall), waterproof, my “soft shell” which is a cheap Mountain Warehouse fleece with the lower arms cut off…
Couple of big sticky plasters and some painkillers (got a couple of tramadol in there, in case I ever want to walk off a hill with a broken foot or something), phone and money. Oh and headphones for the phone.
Plus loads and loads of food, I like to eat as I ride. Clif Shots, energy bars, gels, dextrose tablets. Oh, and if I’m anywhere remote a foil blanket, good for keeping warm but better for signalling help.