Integration to automatically write and publish AI meta descriptions

Hi all, first-time poster! I'm looking for a tool to integrate with a custom build PHP platform that will trawl 1000s of product pages and update (or in some cases, write from scratch) their SEO meta descriptions. Ideally we'd be able to input a set of keyphrases and terms to mix through -- any idea of a tool that does this that doesn't cost $1000 a month? Thanks, Michael