Yes it's just esbuild and SEA BUT that's actually the point. SEA is officialy supported by node.js and it constantly improves. Remember pkg and nexe supports only the older versions of node.js (~14) and astra supports the latest ones.

So in a way, the "magic sauce" it that it doesn't try to do anything fancy. I made astra beacuse i needed to compile js to exe for latest versions.

I wanted astra to be simple, built on official tools, and be future-proof.