does reitit can modify a middleware dynamically?

@haiyuan.vinurs depends on how dynamically. The middleware chain (and the middleware) can be modified at router creation. At request-time, the chain is compiled and thus static. The mw can still do whatever, based on endpoint & request.

Guide on transforming the chain here: https://cljdoc.org/d/metosin/reitit/0.3.1/doc/ring/transforming-middleware-chain

does the arguments for middleware are static at compile time

so the argument for middleware can not changed at run time?

They can't. Recreating the router is the only way to reset the mw arguments.