Wanted to share here as well in case someone missed it
there is nowadays also https://github.com/exoscale/interceptor
for malli, inlined the interceptors, all sync, not much code and pretty fast too https://github.com/metosin/malli/blob/master/src/malli/core.cljc#L490-L492
Existing libraries: • Pedestal’s http://pedestal.io/reference/interceptors, • Frakiesardos https://github.com/frankiesardo/tripod • Metosin’s https://github.com/metosin/sieppari, • Eric Normand’s https://lispcast.com/a-model-of-interceptors/, • and LambdaIsland’s https://lambdaisland.com/episodes/interceptors-concepts. • Exoscale https://github.com/exoscale/interceptor • Lambda-toolshed https://github.com/lambda-toolshed/papillon