MOSS-Image JSON layout prompts, explained
Think in text and object boxes. A short introduction to centered coordinates and the studio’s visual layout builder.
A layout is a plan for attention. Put the headline where it can breathe, leave room for the artwork, and give the small details a consistent place to live.
From a sketch to a brief
In the studio layout builder, add one box per element. Use a text box for a headline or a date, and an object box for an illustration. Edit the content and description, then move or resize each box. The JSON panel reflects your composition as you work.
Copy the JSON to save a version before experimenting. Send it to the generator when you are ready to test the composition. Your style description still matters: a box alone does not choose a typeface or create a visual hierarchy.
Understanding the coordinates
The official layout format uses items with text or object labels, captions and bounding boxes. Boxes use centered pixel coordinates in [y_min, x_min, y_max, x_max] order. On a 1024 × 1024 image, the center is zero and each edge is 512 pixels away. Image dimensions must be positive multiples of 16. These conventions come from the official MOSS-Image user guide.
The visual builder handles these calculations. When you change the canvas ratio, it recalculates the boxes while preserving their relative positions. An earlier copy of the JSON stays unchanged, so copy it again after resizing.
Leave room for interpretation
OpenMOSS describes layout prompting as experimental. Treat the boxes as compositional guidance and inspect the generated image; placement and text may vary.
Try a modest first layout: one title, one illustration and one footer. If the design feels cramped, remove an element before adding more instructions. Keep the clearest version of the brief and compare one change at a time.