diff --git a/docs-autobuilder.asd b/docs-autobuilder.asd
new file mode 100644
index 0000000..efe653a
--- /dev/null
+++ b/docs-autobuilder.asd
@@ -0,0 +1,14 @@
+(defsystem "docs-autobuilder" 
+  :class :package-inferred-system
+  :author "Alexander Artemenko"
+  :license "Unlicense"
+  :pathname "src"
+  :description "A wrapper which watches on filesystem and runs DOCS-BUILDER automatically."
+  :homepage "https://40ants.com/docs-builder"
+  :bug-tracker "https://github.com/40ants/docs-builder/issues"
+  :source-control (:git "https://github.com/40ants/docs-builder")
+  :depends-on ("docs-autobuilder/autobuilder"))
+
+
+(asdf:register-system-packages "lack-app-file" '("LACK.APP.FILE"))
+(asdf:register-system-packages "lack" '("LACK.COMPONENT"))
diff --git a/src/autobuilder.lisp b/src/autobuilder.lisp
new file mode 100644
index 0000000..827973e
--- /dev/null
+++ b/src/autobuilder.lisp
@@ -0,0 +1,142 @@
+(uiop:define-package #:docs-autobuilder
+  (:use #:cl)
+  (:import-from #:lack.component)
+  (:import-from #:lack.app.file)
+  (:import-from #:usocket)
+  (:import-from #:clack)
+  (:import-from #:bordeaux-threads)
+  (:import-from #:docs-builder)
+  (:import-from #:fs-watcher)
+  (:import-from #:trivial-open-browser
+                #:open-browser)
+  (:export #:build
+           #:stop))
+(in-package #:docs-autobuilder)
+
+
+(defvar *app* nil)
+
+(defvar *server* nil)
+
+(defvar *thread* nil)
+
+
+(defun port-available-p (port interface)
+  (handler-case (let ((socket (usocket:socket-listen interface port :reuse-address t)))
+                  (usocket:socket-close socket))
+    (usocket:address-in-use-error (e) (declare (ignore e)) nil)))
+
+
+(defun available-port (interface)
+  "Return a port number not in use from 8000 to 60000."
+  (loop for port from 8000 upto 60000
+        if (port-available-p port interface)
+          return port))
+
+
+(defun serve-docs (root env)
+  (let* ((path-info (string-left-trim (list #\/)
+                                      (getf env :path-info)))
+         (path (if (uiop:directory-pathname-p path-info)
+                   (merge-pathnames "index.html" path-info)
+                   path-info))
+         (full-path (merge-pathnames path root)))
+    (if (probe-file full-path)
+        (lack.component:call (make-instance 'lack.app.file:lack-app-file
+                                            :root root
+                                            :file path)
+                             env)
+        (list 404
+              (list :content-type "text/plain")
+              (list (format nil "File ~A not found."
+                            full-path))))))
+
+
+(defun make-app (root)
+  (flet ((docs-server-app (env)
+           (serve-docs root env)))
+    #'docs-server-app))
+
+
+(defun in-subdir-p (root file)
+  (let ((root (namestring root))
+        (file (namestring file)))
+    (and (> (length file)
+            (length root))
+         (string-equal root
+                       (subseq file 0 (length root))))))
+
+
+(defun build (system &key in-thread port (interface "localhost"))
+  (when *server*
+    (error "Server already running."))
+
+  (let* ((system-path (asdf:system-relative-pathname system "./"))
+         (docs-path (handler-bind ((docs-builder:documentation-has-problems
+                                     (lambda (c)
+                                       (let ((restart (find-restart 'continue c)))
+                                         (when restart
+                                           (invoke-restart restart))))))
+                      (docs-builder:build system)))
+         (port (or port
+                   (available-port interface)))
+         (app (make-app docs-path))
+         (server (progn
+                   (log:info "Starting Clack server to serve docs from ~A" docs-path)
+                   (clack:clackup app
+                                  :port port
+                                  :address interface)))
+         (url (format nil "http://~A:~A/"
+                      interface port)))
+    (open-browser url)
+    
+    (labels ((build-system (changed-file)
+               (cond
+                 ((or (in-subdir-p docs-path changed-file)
+                      (string-equal (pathname-name changed-file)
+                                    "README")
+                      (string-equal (pathname-name changed-file)
+                                    "ChangeLog"))
+                  (log:debug "File ~A was changed, but it is in the documentation folder, skipping docs build step."
+                             changed-file))
+                 (t
+                  (log:info "File ~A was changed. Rebuilding the docs of ~A system."
+                            changed-file system)
+                  (handler-case
+                      (progn
+                        (ql:quickload system)
+                        (docs-builder:build system))
+                    (docs-builder:documentation-has-problems (c)
+                      (log:error "Unable to build docs for ~A system. ~A"
+                                 system c))
+                    (error ()
+                      (log:error "Unable to build docs for ~A system."
+                                 system))))))
+             (run-docs-autobuilder ()
+               (fs-watcher:watch system-path #'build-system)))
+      (cond
+        (in-thread
+         (setf *app* app)
+         (setf *server* server)
+         (setf *thread*
+               (bordeaux-threads:make-thread #'run-docs-autobuilder
+                                             :name (format nil "Docs Autobuilder for ~A: ~A"
+                                                           system url))))
+        (t
+         (unwind-protect
+              (run-docs-autobuilder)
+           (clack:stop server))))
+
+      (values))))
+
+
+(defun stop ()
+  (when *server*
+    (clack:stop *server*)
+    (setf *server* nil
+          *app* nil))
+  (when *thread*
+    (when (bordeaux-threads:thread-alive-p *thread*)
+      (bordeaux-threads:destroy-thread *thread*))
+    (setf *thread* nil))
+  (values))