Native Messaging!

chrome/common/extensions/api/extension.json

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 [
   {
     "namespace": "extension",
     "nocompile": true,
     "dependencies": [ "events", "tabs" ],
     "types": [
@@ skipping 219 matching lines @@
           }
         ]
       },
       {
         "name": "setUpdateUrlData",
         "type": "function",
         "description": "Sets the value of the ap CGI parameter used in the extension's update URL.  This value is ignored for extensions that are hosted in the Chrome Extension Gallery.",
         "parameters": [
           {"type": "string", "name": "data", "maxLength": 1024}
         ]
+      },
+      {
+        "name": "sendNativeMessage",
+        "type": "function",
+        "description": "Send a single message to a registered native application.",
+        "parameters": [
+          {
+            "name": "registeredNativeApp",
+            "description": "The name of the registered native app.",
+            "type": "string"
+          },
+          {
+            "name": "data",
+            "description": "The object that will be passed to the registered native app.",
+            "type": "object",
+            "additionalProperties": {
+              "type": "any"
+            }
+          },
+          {
+            "type": "function",
+            "name": "callback",
+            "optional": true,
+            "description": "Called with the response from the native app.",
+            "parameters": [
+              {
+                "name": "nativeResponse",
+                "type": "object",
+                "description": "Whatever the native app responds with.",
+                "additionalProperties": {
+                  "type": "any"
+                }
+              }
+            ]
+          }
+        ]
       }
     ],
     "events": [
       {
         "name": "onConnect",
         "type": "function",
         "unprivileged": true,
         "anonymous": true,
         "description": "Fired when a connection is made from either an extension process or a content script.",
         "parameters": [
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         ],
         "returns": {
           "type": "boolean",
           "optional": "true",
           "description": "Return true from the event listener if you wish to call <code>sendResponse</code> after the event listener returns."
         }
       }
     ]
   }
 ]