How I built automated Google Business Profile(GBP) posting with the GBP API (and what I learned)

I built a feature recently that I wanted to write up — automated weekly Google Business Profile posts triggered by a cron job. Here is how it works, what the GBP API is actually like, and the gotchas I ran into.

The problem

Local business owners almost never post on Google Business Profile consistently, even though it directly helps local search rankings. The friction is the problem — it is one more task that never gets done.

So I built a system that does it automatically every Monday.

The stack