Async Http Client - Clojure
Clojure CSS Emacs Lisp
Latest commit 70429fb Sep 8, 2016 @cch1 Ignore leiningen profiles.clj

http.async.client - Asynchronous HTTP Client - Clojure

http.async.client is the Asynchronous HTTP Client for Clojure. It is promise-based and uses the Asynchronous Http Client for Java for the heavy lifting.


This library uses semantic versioning. An overview of changes by version is available in the changelog.


All released artifacts are deployed to Clojars.

Build status

TravisCI is used to track the build status of intermediate commits on the following branches:



Declare dependency (using leiningen, in this example):

(defproject your-project "1.0.0-SNAPSHOT"
  :description "Your project description"
  :dependencies [[org.clojure/clojure "1.6.0"]
                 [http.async.client "1.2.0"]])

Asynchronous GET request

(ns async-get
  (:require [http.async.client :as http]))

(with-open [client (http/create-client)]
  (let [response (http/GET client "")]
    (-> response

WebSocket client

(ns ws-client
  (:require [http.async.client :as http]))

(def url "ws://remote-websocket-url:1337")

(defn on-open [ws]
  (println "Connected to WebSocket."))

(defn on-close [ws code reason]
  (println "Connection to WebSocket closed.\n"
           (format "[%s] %s" code reason)))

(defn on-error [ws e]
  (println "ERROR:" e))

(defn handle-message [ws msg]
  (prn "got message:" msg))

(defn -main []
  (println "Connecting...")
  (with-open [client (http/create-client)]
    (let [ws (http/websocket client
                             :open  on-open
                             :close on-close
                             :error on-error
                             :text handle-message)]
      ; this loop-recur is here as a placeholder to keep the process
      ; from ending, so that the message-handling function will continue to
      ; print messages to STDOUT until Ctrl-C is pressed
      (loop [] (recur)))))

More info

It runs with Clojure 1.5.1, 1.6.0, 1.7.0 and 1.8.0. Development is against Clojure 1.8.0.

For complete documentation refer to the project documentation index.

http.async.client is distributed under Apache License, Version 2.0.

If you would like to report an problem or submit a request, create an issue.

Finally, much thanks is owed to those contributors who have made this project so successful.