Is there a way to list all the available snippets?

[navxio]

for the given file type of course

[felixr]

Have a look at https://github.com/hrsh7th/vim-vsnip/blob/b05641ca8c7ebd396017121219047c480182a743/autoload/vsnip.vim#L128-L144

The code calls vsnip#source#find(bufnr('%')) to get all snippets from all sources for the current buffer (`bufnr('%')). It returns a list of list of snipped (ie [ [ snip, snip], [snip, ...] ]) and each snippet is a dictionary matching the JSON