PyCall should probably work. But depending on your use case, I’d suggest considering writing to the APIs directly in Julia using HTTP.jl or Websockets.jl. Most endpoints can be called with just a few lines of code.
CCXT only covers a fraction of the available API endpoints, even for popular exchanges and has many inconsistencies. And for any real trading, you’ll need to familiarize yourself with the idiosyncrasies of each exchange anyway.
It seems that some work have been done at https://github.com/panifie/PingPong.jl/tree/master/Ccxt
but I don’t know how complete it’s and if / when it will be published “upstream” (ie in CCXT repository)