@wilkerlucio sadly not. I do have my action wrapped in a function , given as value for :action. what I meant was, my mutate function is called twice, but my action is called only once, so that's ok. it was just suspicious, and I thought it might be a clue to why I am getting this error.

@wilkerlucio Here's the code:

(ns om.test
  (:require [goog.dom :as gdom]
            [om.next :as om :refer-macros [defui]]
            [om.dom :as dom]))

(enable-console-print!)

(def app-state (atom {:search-text ""}))

(defmulti read om/dispatch)
(defmulti mutate om/dispatch)


(defmethod mutate `update-search-text [{:keys [state]} k {:keys [value]}]
  (println "update-search-text" value)
  {:action #(swap! app-state assoc :search-text value)})


(defmethod read :default [{:keys [state]} k p]
  {:value (get @state k)})


(defui Customers

  static om/IQuery
  (query [this]
    [:search-text])

  Object
  (render [this]
    (let [{:keys [customers search-text]} (om/props this)]
      ;(println "Rendering Customers" (om/props this))
      (dom/p nil
             (dom/input #js {:value       search-text
                             :type        "text"
                             :onChange    #(om/transact! this `[(update-search-text {:value ~(.. % -target -value)})])
                             }))
      )))

(def customers (om/factory Customers))


(defui RootView

  static om/IQuery
  (query [this]
    [:search-text])

  Object
  (render [this]
    (let [{:keys [page] :as props} (om/props this)]
      ;(println "Rendering root" (om/props this))
      (dom/div nil
               (customers props)))))


(def reconciler
  (om/reconciler
    {:state  app-state
     :parser (om/parser {:read read :mutate mutate})
     }))



(om/add-root! reconciler
              RootView (gdom/getElement "app"))

when I use Customers as root view, everything's fine of course