@michaelkleber, @JensenPaul

One of the things we've added in the Ad Selection API is a platform header to indicate to the B&A seller side what capabilities the client (browser) requires for a private auction to occur.

Example:

Sec-Auction-Platform-Support: "Microsoft Edge";min-version="3.11.0.0", "Not;A=Brand";min-version="3.10.0.0"

Can we add this to the Chromium impl as a way for any seller to understand what platform support they would need to handle a given auction? We feel this would help with both different potential server images as well as provide a mechanism as the API and underlying auction data structure evolves if there are any breaking changes or required additions that old versions may not be compatible with.

Once we align on if/what is to be added happy to move this over to a crbug and/or have patches put up to allow any embedder to specify platform details.