Stable media, bounded delivery.

Roles and order

Each item needs a stable provider ID, a unique positive order, and one role: photo, hero, floorplan, site_plan, brochure, or document. Use one hero where available; unchanged exports retain the same IDs and ordering.

Transport rules

Use absolute HTTPS URLs that work without cookies, expiring signatures, interactive login or IP allow-lists. Redirects stay on HTTPS. Content type must match declared MIME type. Placeholder assets, tracking pixels and HTML error pages are invalid.

Formats and dimensions

JPEG, PNG and WebP are accepted for raster images. PDF is accepted only for brochure/document roles. Recommended originals are at least 2400 pixels on the longest side, with ordinary photos between 4:5 and 21:9. Never upscale a small source.

Duplicates and metadata

Checksums take precedence for duplicate detection; normalised final URL is the fallback. Remove unnecessary EXIF location, device and author metadata. A repeated URL with another role is still a duplicate unless the bytes intentionally differ.

Compatibility note

Kyero v3.9 documents a maximum of 50 photos and a 1280×960 baseline. zentra keeps 50 as a practical recommendation, while the v1 hard ceiling is 200 after production evidence showed properties with up to 176 image rows.