This NIP is not yet in main. Here is an overview of PRs referencing this NIP. 
Update 90.md OPEN @starbackr-dev
NIP90 Job Result kinds CLOSED @cj-chua
added negative_prompt to kind 65004, renamed prompt param to extra_prompt CLOSED @believethehype
NIP-90: Data Vending Machines MERGED @pablof7z
NIP-90: Bitcoin PSBTs OPEN @ronaldstoner