I'm looking for a slim bag, like the Opsrey Arcane fanny pack, that would use my pant belt rather than come with its own waist straps.

I'm sure these exist but I can't find one. What are they called (if I search for belt bag, fanny packs still get returned).

I'm looking for something on the smaller side that I can use to carry stuff that would normally go into cargo pant pockets when I wear regular pants. Various small items.

Amazon...

diodrio Belt Pouch for Men Women YKK Zippers EDC Pouch, Belt Bag Waist Pack for Hiking, Water Resistant, Waxed Canvas, Olive

I have this one, does the job.

Thanks! I guess I'm looking for "Belt Pouch"

May not be exactly what you're looking for but, check some of these brands out...
Friend of mine EDC's with this from Aer. They also make it in X-Pac fabric which I really like.

Other brands to consider-
Evergoods- my current favorite, just picked up a couple of their smaller gear pouches for travel.
Peak Design
Alpaka Gear
Able Carry

Elite Survival Systems Liberty gun pack. It for CCW, but you can use without your pistol. TomToc on Amazon has pouches that may work for you, also made from XPac.

Something like this? https://tuffpossumgear.com/product/belt-pouch/

Mountain Hardwear and other make belt pouches that go on hip bets of hiking packs. That may work for you.

Great! Thanks guys. This helps. Good to have variety. For my immediate need, I'm looking for something small - I found something called a lighter pouch that may fit my needs. Looks small and light.

But I've also been wondering about something for EDC so these are great options. A strapped fanny pack over pant belt was too cumbersome and uncomfortable. Will look into suggestions above.

Another option. I keep it rolled on my belt and can deploy for empty mags, etc.

Flat Line Fiber Co Dump Pouch

Here is a screenshot of the one I referenced above

Thanks guys. Very helpful. Important to know the correct reference - belt pouch. Some good options above.

I have a nice belt pack. It’s the Helikon Tex Bandicoot waist pack. You can remove the strap that comes with it, and just use your belt. I may have a Glock 43X in mine, but I ain’t tellin’.

I don’t use the belt on my pants, but I wear it on one of those nylon extra thick belts you order from Amazon.

https://www.helikon-tex.us/ban...st-pack-cordura.html

Uncle Mikes Gun Pak - well made, with a pouch to conceal a gun.