We have also considered JavaScriptCore (used by Bun) and QuickJS. We did choose v8 because it's state of the art, quite well documented and easy to embed.

The code is made to support others JS engine in the future. We do want to add a lightweight alternative like QuickJS or Kiesel https://kiesel.dev/

Thank You I was thinking of JSC and Bun as well. Was half expecting JSC since that combination seems to work well.