I try to build an exercise. I want to produce a random 256-bit seed to give as input and ask for a Monero stealth address.

1. What are the restrictions on this seed in practice? I know it must be a legit scalar but is that satisfied by the 256-bit length? Can it be any random 256-bit number? If not, is there a js library for that calculation?

2. I have to write this exercise's grading program in nodejs (it is part of a bigger project). Does anyone know where I can find a js library that supports the needed calculations? (./keccak, ./bytes_to_words, ./words_to_bytes, ./sc_reduce32, ./private_key_to_public_key).

For reference, the process for the calculation of a Monero stealth address is explained here very well.