diff --git a/klippy/msgproto.py b/klippy/msgproto.py
index 5feb350d..6bb5c159 100644
--- a/klippy/msgproto.py
+++ b/klippy/msgproto.py
@@ -6,8 +6,8 @@
 import json, zlib, logging
 
 DefaultMessages = {
-    0: "identify_response offset=%u data=%.*s",
-    1: "identify offset=%u count=%c",
+    "identify_response offset=%u data=%.*s": 0,
+    "identify offset=%u count=%c": 1,
 }
 
 MESSAGE_MIN = 5
@@ -190,7 +190,7 @@ class MessageParser:
         self.config = {}
         self.version = self.build_versions = ""
         self.raw_identify_data = ""
-        self._init_messages(DefaultMessages, DefaultMessages.keys())
+        self._init_messages(DefaultMessages)
     def check_packet(self, s):
         if len(s) < MESSAGE_MIN:
             return 0
@@ -296,10 +296,10 @@ class MessageParser:
             #traceback.print_exc()
             raise error("Unable to encode: %s" % (msgname,))
         return cmd
-    def _init_messages(self, messages, parsers):
-        for msgid, msgformat in messages.items():
+    def _init_messages(self, messages, output_ids=[]):
+        for msgformat, msgid in messages.items():
             msgid = int(msgid)
-            if msgid not in parsers:
+            if msgid in output_ids:
                 self.messages_by_id[msgid] = OutputFormat(msgid, msgformat)
                 continue
             msg = MessageFormat(msgid, msgformat)
@@ -311,11 +311,14 @@ class MessageParser:
                 data = zlib.decompress(data)
             self.raw_identify_data = data
             data = json.loads(data)
-            messages = data.get('messages')
             commands = data.get('commands')
-            self.command_ids = commands
             responses = data.get('responses')
-            self._init_messages(messages, commands+responses)
+            output = data.get('output', {})
+            all_messages = dict(commands)
+            all_messages.update(responses)
+            all_messages.update(output)
+            self.command_ids = sorted(commands.values())
+            self._init_messages(all_messages, output.values())
             static_strings = data.get('static_strings', {})
             self.static_strings = {int(k): v for k, v in static_strings.items()}
             self.config.update(data.get('config', {}))
diff --git a/scripts/buildcommands.py b/scripts/buildcommands.py
index 2b892366..1c3448fe 100644
--- a/scripts/buildcommands.py
+++ b/scripts/buildcommands.py
@@ -131,7 +131,7 @@ class HandleCommandGeneration:
     def __init__(self):
         self.commands = {}
         self.encoders = []
-        self.msg_to_id = { m: i for i, m in msgproto.DefaultMessages.items() }
+        self.msg_to_id = dict(msgproto.DefaultMessages)
         self.messages_by_name = { m.split()[0]: m for m in self.msg_to_id }
         self.all_param_types = {}
         self.ctr_dispatch = {
@@ -172,16 +172,20 @@ class HandleCommandGeneration:
             # The mcu currently assumes all message ids encode to one byte
             error("Too many message ids")
     def update_data_dictionary(self, data):
-        messages = { msgid: msg for msg, msgid in self.msg_to_id.items() }
-        data['messages'] = messages
-        commands = [self.msg_to_id[msg]
-                    for msgname, msg in self.messages_by_name.items()
-                    if msgname in self.commands]
-        data['commands'] = sorted(commands)
-        responses = [self.msg_to_id[msg]
-                     for msgname, msg in self.messages_by_name.items()
-                     if msgname not in self.commands]
-        data['responses'] = sorted(responses)
+        command_ids = [self.msg_to_id[msg]
+                       for msgname, msg in self.messages_by_name.items()
+                       if msgname in self.commands]
+        response_ids = [self.msg_to_id[msg]
+                        for msgname, msg in self.messages_by_name.items()
+                        if msgname not in self.commands]
+        data['commands'] = { msg: msgid for msg, msgid in self.msg_to_id.items()
+                             if msgid in command_ids }
+        data['responses'] = {msg: msgid for msg, msgid in self.msg_to_id.items()
+                             if msgid in response_ids }
+        output = { msg: msgid for msg, msgid in self.msg_to_id.items()
+                   if msgid not in command_ids and msgid not in response_ids }
+        if output:
+            data['output'] = output
     def build_parser(self, parser, iscmd):
         if parser.name == "#output":
             comment = "Output: " + parser.msgformat
@@ -412,7 +416,7 @@ class HandleIdentify:
         data = {}
         for h in Handlers:
             h.update_data_dictionary(data)
-        datadict = json.dumps(data, separators=(',', ':'))
+        datadict = json.dumps(data, separators=(',', ':'), sort_keys=True)
 
         # Write data dictionary
         if options.write_dictionary: