KDP Interior Forge — Print-Ready Book Interiors

Turns a manuscript into a print-ready Amazon KDP paperback interior: mirror margins with the gutter sized to the real page count, chapters opening on right-hand leaves verified against the rendered PDF, running heads that vanish on chapter openers, a live table of contents and proper front matter. Then it gives you the exact spine width and cover canvas — the number most authors get wrong. Give it your manuscript and whether you want. It picks the trim size if you don't have one.