Your project's own material, reports, briefs, specifications, schedules, notes, is uploaded and managed through Manage Documents in an area of work. The AI uses these documents as the evidence base for its answers and drafts.
CogniBuild accepts PDF and Word files and reads the text in them. It does not interpret images, so scanned pages and image-only PDFs cannot be read, even if you can see the words on screen. If a document will not process, uploading a version with selectable text, such as the original digital file rather than a scan, usually resolves it.
Drawings are fine to upload: the written text on them, such as title blocks, notes, and schedules, will be used, though the drawing itself is not read as an image.