no public api for that

See https://ask.clojure.org/index.php/602/provide-a-chan-function-to-determine-if-given-var-is-channel

it's a little more subtle than it looks as channels are actually made up of read ports and write ports and some channels only do part of that

Instead of chan?, how about writable? and readable?

I guess I'd ask the OP what the context for wanting this is

My problem is that sometimes a channel gets put in another channel, and I need to take the value from it. Until I figure out where it's coming from, I'm currently just doing a (try (<! maybe-chan) (catch Exception _ maybe-chan).

I've had success with (instance? ManyToManyChannel v)

yeah it’s a bit sloppy, but we do (def AsyncChan (class (async/chan))) in a schemata file you can use that with https://github.com/plumatic/schema checking e.g.

(s/defn my-f [ch :- AsyncChan] ,,,)