Add wake word phrase to voice assistant start command (#6290)

esphome/components/voice_assistant/__init__.py

@@ -42,6 +42,8 @@ CONF_AUTO_GAIN = "auto_gain"
 CONF_NOISE_SUPPRESSION_LEVEL = "noise_suppression_level"
 CONF_VOLUME_MULTIPLIER = "volume_multiplier"
 
+CONF_WAKE_WORD = "wake_word"
+
 
 voice_assistant_ns = cg.esphome_ns.namespace("voice_assistant")
 VoiceAssistant = voice_assistant_ns.class_("VoiceAssistant", cg.Component)
@@ -285,6 +287,7 @@ VOICE_ASSISTANT_ACTION_SCHEMA = cv.Schema({cv.GenerateID(): cv.use_id(VoiceAssis
     VOICE_ASSISTANT_ACTION_SCHEMA.extend(
         {
             cv.Optional(CONF_SILENCE_DETECTION, default=True): cv.boolean,
+            cv.Optional(CONF_WAKE_WORD): cv.templatable(cv.string),
         }
     ),
 )
@@ -293,6 +296,9 @@ async def voice_assistant_listen_to_code(config, action_id, template_arg, args):
     await cg.register_parented(var, config[CONF_ID])
     if CONF_SILENCE_DETECTION in config:
         cg.add(var.set_silence_detection(config[CONF_SILENCE_DETECTION]))
+    if wake_word := config.get(CONF_WAKE_WORD):
+        templ = await cg.templatable(wake_word, args, cg.std_string)
+        cg.add(var.set_wake_word(templ))
     return var