diff --git a/features/support/env.el b/features/support/env.el
index 52ba29e..2e277ec 100644
--- a/features/support/env.el
+++ b/features/support/env.el
@@ -71,9 +71,14 @@
             for path = (ein:$notebook-notebook-path nb)
             do (ein:log 'debug "Notebook %s still open" path)
             finally do (assert nil)))
-  (let ((stragglers (file-name-all-completions "Untitled"
-                                               ein:testing-jupyter-server-root)))
-    (should-not stragglers)))
+  (cl-loop repeat 5
+           for stragglers = (file-name-all-completions "Untitled"
+                                                       ein:testing-jupyter-server-root)
+           until (null stragglers)
+           do (message "ein:testing-after-scenario: fs stale handles: %s"
+                       (mapconcat #'identity stragglers ", "))
+           do (sleep-for 0 1000)
+           finally do (should-not stragglers)))
 
 (Setup
  (ein:dev-start-debug)
diff --git a/lisp/ein-contents-api.el b/lisp/ein-contents-api.el
index 8d02a68..843ddf3 100644
--- a/lisp/ein-contents-api.el
+++ b/lisp/ein-contents-api.el
@@ -63,26 +63,13 @@ global setting.  For global setting and more information, see
   :type 'boolean
   :group 'ein)
 
-(defun ein:content-url (content &rest params)
-  (apply #'ein:content-url* (ein:$content-url-or-port content) (ein:$content-path content) params))
-
-(defun ein:content-url* (url-or-port path &rest params)
-  (let* ((which (if (< (ein:notebook-version-numeric url-or-port) 3)
-                    "notebooks" "contents"))
-         (api-path (concat "api/" which)))
-    (url-encode-url (apply #'ein:url
-                           url-or-port
-                           api-path
-                           path
-                           params))))
-
 (defun ein:content-query-contents (url-or-port path callback errback &optional iteration)
   "Register CALLBACK of arity 1 for the contents at PATH from the URL-OR-PORT.
 ERRBACK of arity 1 for the contents."
   (unless iteration
     (setq iteration 0))
   (ein:query-singleton-ajax
-   (ein:content-url* url-or-port path)
+   (ein:notebooklist-url url-or-port path)
    :type "GET"
    :timeout ein:content-query-timeout
    :parser #'ein:json-read
@@ -276,7 +263,7 @@ ERRBACK of arity 1 for the contents."
                          (when callback* (funcall callback* nil)))))
                     url-or-port callback)
    callback))
-
+
 ;;; Save Content
 
 (defun ein:content-save-legacy (content &optional callback cbargs errcb errcbargs)
@@ -287,7 +274,13 @@ ERRBACK of arity 1 for the contents."
    :timeout ein:content-query-timeout
    :data (ein:content-to-json content)
    :success (apply-partially #'ein:content-save-success callback cbargs)
-   :error (apply-partially #'ein:content-save-error (ein:content-url content) errcb errcbargs)))
+   :error (apply-partially #'ein:content-save-error
+                           (ein:content-url content)
+                           errcb errcbargs)))
+
+(defsubst ein:content-url (content)
+  (ein:notebooklist-url (ein:$content-url-or-port content)
+                        (ein:$content-path content)))
 
 (defun ein:content-save (content &optional callback cbargs errcb errcbargs)
   (if (>= (ein:$content-notebook-version content) 3)
diff --git a/lisp/ein-notebook.el b/lisp/ein-notebook.el
index ed88317..b8a7613 100644
--- a/lisp/ein-notebook.el
+++ b/lisp/ein-notebook.el
@@ -221,16 +221,9 @@ combo must match exactly these url/port you used format
 
 ;;; Open notebook
 
-(defun ein:notebook-url (notebook)
-  (ein:notebook-url-from-url-and-id (ein:$notebook-url-or-port notebook)
-                                    (ein:$notebook-api-version notebook)
-                                    (ein:$notebook-notebook-path notebook)))
-
-(defun ein:notebook-url-from-url-and-id (url-or-port api-version path)
-  (cond ((= api-version 2)
-         (ein:url url-or-port "api/notebooks" path))
-        ((>= api-version 3)
-         (ein:url url-or-port "api/contents" path))))
+(defsubst ein:notebook-url (notebook)
+  (ein:notebooklist-url (ein:$notebook-url-or-port notebook)
+                        (ein:$notebook-notebook-path notebook)))
 
 (defun ein:notebook-open--decorate-callback (notebook existing pending-clear callback no-pop)
   "In addition to CALLBACK,
@@ -1418,20 +1411,6 @@ watch the fireworks!"
 ;; permanent local.
 (put 'ein:notebook-mode 'permanent-local t)
 
-(defun ein:notebook-open-in-browser (&optional print)
-  "Open current notebook in web browser.
-When the prefix argument (``C-u``) is given, print page is opened.
-Note that print page is not supported in IPython 0.12.1."
-  (interactive "P")
-  (let ((url (apply #'ein:url
-                    (ein:$notebook-url-or-port ein:%notebook%)
-                    (if (>= (ein:$notebook-api-version ein:%notebook%) 3)
-                        "notebooks")
-                    (ein:$notebook-notebook-path ein:%notebook%)
-                    (if print (list "print")))))
-    (message "Opening %s in browser" url)
-    (browse-url url)))
-
 (defun ein:notebook-fetch-data (notebook callback &optional cbargs)
   "Fetch data in body tag of NOTEBOOK html page.
 CALLBACK is called with a plist with data in the body tag as
diff --git a/lisp/ein-notebooklist.el b/lisp/ein-notebooklist.el
index 91f5eb1..dec1af7 100644
--- a/lisp/ein-notebooklist.el
+++ b/lisp/ein-notebooklist.el
@@ -132,9 +132,10 @@ This function adds NBLIST to `ein:notebooklist-map'."
   "Get an instance of `ein:$notebooklist' by URL-OR-PORT as a key."
   (gethash url-or-port ein:notebooklist-map))
 
-(defun ein:notebooklist-url (url-or-port version &optional path)
-  (let ((base-path (cond ((= version 2) "api/notebooks")
-                         ((>= version 3) "api/contents"))))
+(defun ein:notebooklist-url (url-or-port path)
+  (let* ((version (ein:notebook-version-numeric url-or-port))
+         (base-path (cond ((= version 2) "api/notebooks")
+                          (t "api/contents"))))
     (ein:url url-or-port base-path path)))
 
 (defun ein:notebooklist-sentinel (url-or-port process event)
@@ -280,8 +281,7 @@ This function is called via `ein:notebook-after-rename-hook'."
                       nil t nil nil "default" nil)))
   (let* ((notebooklist (ein:notebooklist-list-get url-or-port))
          (path (ein:$notebooklist-path notebooklist))
-         (version (ein:$notebooklist-api-version notebooklist))
-         (url (ein:notebooklist-url url-or-port version path)))
+         (url (ein:notebooklist-url url-or-port path)))
     (ein:query-singleton-ajax
      url
      :type "POST"
@@ -364,8 +364,7 @@ This function is called via `ein:notebook-after-rename-hook'."
            (apply-partially
             (lambda (url* settings* _kernel)
               (apply #'ein:query-singleton-ajax url* settings*))
-            (ein:notebook-url-from-url-and-id
-             url-or-port (ein:$notebooklist-api-version notebooklist) path)
+            (ein:notebooklist-url url-or-port path)
             (list :type "DELETE"
                   :complete (apply-partially
                              #'ein:notebooklist-delete-notebook--complete
diff --git a/lisp/ein-process.el b/lisp/ein-process.el
index 7b0fd4c..56f9404 100644
--- a/lisp/ein-process.el
+++ b/lisp/ein-process.el
@@ -181,10 +181,10 @@
                                          (ein:process-suitable-notebook-dir filename)))
              (path
               (concat (if ein:jupyter-use-containers
-                          (file-name-as-directory
-                           (file-name-base ein:jupyter-docker-mount-point))
+                          (file-name-as-directory (file-name-base ein:jupyter-docker-mount-point))
                         "")
-                      (cl-subseq filename (length (file-name-as-directory nbdir)))))
+                      (cl-subseq (expand-file-name filename)
+                                 (length (file-name-as-directory (expand-file-name nbdir))))))
              (callback2 (apply-partially (lambda (path* callback* buffer url-or-port)
                                            (pop-to-buffer buffer)
                                            (ein:notebook-open url-or-port
diff --git a/lisp/ob-ein.el b/lisp/ob-ein.el
index ef12c0c..3cc2f8f 100644
--- a/lisp/ob-ein.el
+++ b/lisp/ob-ein.el
@@ -333,8 +333,7 @@ if necessary.  Install CALLBACK (i.e., cell execution) upon notebook retrieval."
                     kernelspec)
            (cl-letf (((symbol-function 'y-or-n-p) #'ignore))
              (ein:notebook-close notebook))
-           (ein:query-singleton-ajax
-            (ein:notebook-url notebook)
+           (ein:query-singleton-ajax (ein:notebook-url notebook)
             :type "DELETE")
            (cl-loop repeat 8
                     with fullpath = (concat (file-name-as-directory nbpath) path)