I've got a script that fetches prices for Vanguard frunds from one of the APIs I found their website was making XHR's to. It looks something like (tho I also needed the "Referer: https://vanguard.com
This has worked for most of a year, up til last month, not only for ETFs, but also Vanguard funds like their target retirement funds, and even the target retirement trust fund my company uses for the 401k, but now I'm getting 404s.
I've found this will give me JSON of today's price (but not historical):
And this will give me HTML of historical prices, but not for the Target Retirement 2050 Trust fund my company uses for their 401k:
Does anyone know of APIs to fetch NAV prices for these funds by date?