At a quick glance, I found these:
Forex: - fxempire.com - alphavantage.co
Crypto: - polygon.io - Script for Binance and Coinbase for putting orders I presume
Fixed income: - ecb.europa.eu
Alternative: - hacker-news.firebaseio.com
Macro: - api.nasdaq.com - econdb.com - fred.stlouisfed.org