diff --git a/src/actions/background.js b/src/actions/background.js
new file mode 100644
index 0000000..40b901b
--- /dev/null
+++ b/src/actions/background.js
@@ -0,0 +1,11 @@
+import actions from '../actions';
+
+export function requestCompletions(line) {
+  let command = line.split(' ', 1)[0];
+  let keywords = line.replace(command + ' ', '');
+  return {
+    type: actions.BACKGROUND_REQUEST_COMPLETIONS,
+    command,
+    keywords
+  };
+}
diff --git a/src/actions/index.js b/src/actions/index.js
index 38ced9d..8f22193 100644
--- a/src/actions/index.js
+++ b/src/actions/index.js
@@ -2,5 +2,7 @@ export default {
   CONSOLE_SHOW_COMMAND: 'vimvixen.console.show.command',
   CONSOLE_SET_COMPLETIONS: 'vimvixen.console.set.completions',
   CONSOLE_SHOW_ERROR: 'vimvixen.console.show.error',
-  CONSOLE_HIDE: 'vimvixen.console.hide'
+  CONSOLE_HIDE: 'vimvixen.console.hide',
+
+  BACKGROUND_REQUEST_COMPLETIONS: 'vimvixen.background.request.completions'
 };
diff --git a/src/background/index.js b/src/background/index.js
index 61d4895..a80d1ea 100644
--- a/src/background/index.js
+++ b/src/background/index.js
@@ -2,6 +2,7 @@ import * as actions from '../shared/actions';
 import * as tabs from './tabs';
 import * as zooms from './zooms';
 import KeyQueue from './key-queue';
+import backgroundReducers from '../reducers/background';
 
 const queue = new KeyQueue();
 
@@ -81,22 +82,11 @@ browser.runtime.onMessage.addListener((request, sender) => {
     return keyPressHandle(request, sender);
   case 'event.cmd.enter':
     return cmdEnterHandle(request, sender);
-  case 'event.cmd.tabs.completion':
-    return tabs.getCompletions(request.text).then((tabs) => {
-      let items = tabs.map((tab) => {
-        return {
-          caption: tab.title,
-          content: tab.title,
-          url: tab.url,
-          icon: tab.favIconUrl
-        }
-      });
-      return {
-        name: "Buffers",
-        items: items
-      };
-    });
   default:
     return browser.tabs.sendMessage(sender.tab.id, request);
   }
 });
+
+browser.runtime.onMessage.addListener((action, sender) => {
+  return backgroundReducers(undefined, action, sender.tab.id);
+});
diff --git a/src/console/console-frame.js b/src/console/console-frame.js
index 8b4c17a..063026c 100644
--- a/src/console/console-frame.js
+++ b/src/console/console-frame.js
@@ -45,8 +45,4 @@ export default class ConsoleFrame {
   isErrorShown() {
     return this.element.style.display === 'block' && this.errorShown;
   }
-
-  setCompletions(completions) {
-    return browser.runtime.sendMessage(consoleActions.setCompletions(completions));
-  }
 }
diff --git a/src/console/console.js b/src/console/console.js
index 35d98e0..d79e154 100644
--- a/src/console/console.js
+++ b/src/console/console.js
@@ -1,4 +1,5 @@
 import './console.scss';
+import * as backgroundActions from '../actions/background';
 import Completion from './completion';
 import consoleReducer from '../reducers/console';
 
@@ -21,13 +22,6 @@ const keydownMessage = (input) => {
   };
 };
 
-const keyupMessage = (input) => {
-  return {
-    type: 'vimvixen.command.change',
-    value: input.value
-  };
-};
-
 const handleBlur = () => {
   return browser.runtime.sendMessage(blurMessage());
 };
@@ -88,7 +82,9 @@ const handleKeyup = (e) => {
     return;
   }
   prevValue = e.target.value;
-  return browser.runtime.sendMessage(keyupMessage(e.target));
+  return browser.runtime.sendMessage(
+    backgroundActions.requestCompletions(e.target.value)
+  );
 };
 
 window.addEventListener('load', () => {
diff --git a/src/content/index.js b/src/content/index.js
index deb3506..1a7fa55 100644
--- a/src/content/index.js
+++ b/src/content/index.js
@@ -68,23 +68,6 @@ window.addEventListener("keypress", (e) => {
     });
 });
 
-const doCompletion = (line) => {
-  if (line.startsWith('buffer ')) {
-    let keyword = line.replace('buffer ', '');
-
-    browser.runtime.sendMessage({
-      type: 'event.cmd.tabs.completion',
-      text: keyword
-    }).then((completions) => {
-      vvConsole.setCompletions([completions]);
-    }).catch((err) => {
-      console.error("Vim Vixen:", err);
-      vvConsole.showError(err.message);
-    });
-  }
-  return Promise.resolve();
-};
-
 browser.runtime.onMessage.addListener((action) => {
   switch (action.type) {
   case 'vimvixen.command.blur':
@@ -100,8 +83,6 @@ browser.runtime.onMessage.addListener((action) => {
       console.error("Vim Vixen:", err);
       vvConsole.showError(err.message);
     });
-  case 'vimvixen.command.change':
-    return doCompletion(action.value);
   default:
     return Promise.resolve();
   }
diff --git a/src/reducers/background.js b/src/reducers/background.js
new file mode 100644
index 0000000..eccc8ca
--- /dev/null
+++ b/src/reducers/background.js
@@ -0,0 +1,38 @@
+import * as tabs from '../background/tabs';
+import * as consoleActions from '../actions/console';
+import actions from '../actions';
+
+const doCompletion = (command, keywords, sendto) => {
+  if (command === 'buffer') {
+    return tabs.getCompletions(keywords).then((tabs) => {
+      let items = tabs.map((tab) => {
+        return {
+          caption: tab.title,
+          content: tab.title,
+          url: tab.url,
+          icon: tab.favIconUrl
+        }
+      });
+      let completions = {
+        name: "Buffers",
+        items: items
+      };
+      return browser.tabs.sendMessage(
+        sendto, 
+        consoleActions.setCompletions([completions]));
+    });
+  }
+  return Promise.resolve();
+};
+
+
+
+export default function reducer(state, action = {}, sendto) {
+  // TODO hide sendto object
+  switch (action.type) {
+  case actions.BACKGROUND_REQUEST_COMPLETIONS:
+    return doCompletion(action.command, action.keywords, sendto);
+  default:
+    return Promise.resolve();
+  }
+}
diff --git a/test/actions/background.test.js b/test/actions/background.test.js
new file mode 100644
index 0000000..a3203ee
--- /dev/null
+++ b/test/actions/background.test.js
@@ -0,0 +1,14 @@
+import { expect } from "chai";
+import actions from '../../src/actions';
+import * as backgroundActions from '../../src/actions/background';
+
+describe("background actions", () => {
+  describe("requestCompletions", () => {
+    it('create BACKGROUND_REQUEST_COMPLETIONS action', () => {
+      let action = backgroundActions.requestCompletions('buffer hoge fuga');
+      expect(action.type).to.equal(actions.BACKGROUND_REQUEST_COMPLETIONS);
+      expect(action.command).to.equal('buffer');
+      expect(action.keywords).to.equal('hoge fuga');
+    });
+  });
+});