rate.sx
Curl cryptocurrencies exchange rates
...The service supports multiple coins, fiat conversions, and historical lookups so you can compare prices over time without leaving the terminal. Under the hood it aggregates price feeds and normalizes the results for robust querying, yet keeps the interface dead simple. Because it’s HTTP-based, you can integrate it into shell prompts, tmux status lines, CI logs, dashboards, or chat bots. It’s ideal for developers and power users who want quick answers and scriptable endpoints without installing a heavy client.