There's a langchain implementation that's fairly mature and definitely in production use (I saw the authors handle above actually :D ). Langgraph-style libraries exist (there's one called Magus that I've used) but I think that's where there could be some more efforts. Although it's important to note that building something comparable to langgraph isn't too hard in Elixir with its process model, and most Elixir devs could probably do it, but unfortunately that's not obvious to your average person searching "langgraph implementation in Elixir". There's no langsmith integration but the telemetry implementation in Erlang and Elixir is really nice so once some patterns around running chains and graphs emerge publicly (there's a few companies that I'd bet have private repos implementing their own equivalents of langgraph) I imagine integrating to langsmith would go pretty quick