Every material attribute the platform carries, and what it drives.

A material master sheet is only worth filling in if the figures reach something. This endpoint states, per key, which part of the costing engine reads it — or, where nothing does, says so in those words and gives the reason. There is no third state: a key that reached the engine and was never read would price your part identically whether you set it or not, and nothing on the quote would tell you.

Two scopes appear together because they are indistinguishable by the time pricing sees them: grade keys are the ones you can state on your own materials and override on catalogue ones, and group keys are stated by the workpiece-material group and inherited by every grade on it that does not state its own.

The grade set is exactly what the write paths accept, and they accept nothing else: attributes on a grade or an override is a closed vocabulary, and an unknown key or an out-of-set verdict is refused rather than stored. A key that carries a closed set of verdicts — the route gates like laser_cuttable or weldability_class — lists them in values; a numeric key carries a unit instead and leaves values null.

Ordered: the wired attributes first, then the display-only ones, alphabetically within each.