Will a cap work with OEM bed rails?

I’m not sure if I’m using the right phrase, but my 2021 SR5 has factory rails on the inside of the bed with moveable tie down points. Is this compatible with a cap or will I have to remove the rails?

also does anyone have experience with Jason caps?

 

Yes, my topper uses that rail for the clamps that anchor the topper to bed. Of course the OE tie down points have to be pulled at times, as the clamps limit their ability to slide the whole length.
BTW- Be prepared for rear sag, especially if you use bed for even the smallest amounts of loads.

 

Yes.