Create and edit unixfs by hand

Let’s say I’ve got database of IPFS’ hashes and corresponding filenames with another metadata. I want to create unixfs with these hashes, but without using original files. I also want to add or delete some files from directory(I know that the hash of directory will change, but that’s not the problem right now). Is it possible with js-ipfs/go-ipfs or api?

Take a look at the ipfs object command. Here’s an example of adding files and folders in IPFS to an existing directory.