From 9df461964abee23e1bf1f6dd00be886987fff086 Mon Sep 17 00:00:00 2001
From: Erik Montnemery <erik@montnemery.com>
Date: Fri, 11 Jun 2021 23:16:06 +0200
Subject: [PATCH] Document trigger id (#18159)

---
 source/_docs/automation/trigger.markdown | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/source/_docs/automation/trigger.markdown b/source/_docs/automation/trigger.markdown
index d1b448b7875..e1477349cbd 100644
--- a/source/_docs/automation/trigger.markdown
+++ b/source/_docs/automation/trigger.markdown
@@ -22,6 +22,27 @@ An automation can be triggered by an event, with a certain entity state, at a gi
 - [Geolocation trigger](#geolocation-trigger)
 - [Device triggers](#device-triggers)
 
+## Trigger id
+
+All triggers can be assigned an optional `id`. If the id is omitted, it will instead be set to the index of the trigger. The `id` can be referenced from trigger conditions.
+
+```yaml
+automation:
+  trigger:
+    - platform: event
+      event_type: "MY_CUSTOM_EVENT"
+      id: "custom_event"
+    - platform: mqtt
+      topic: "living_room/switch/ac"
+      id: "ac_on"
+    - platform: state  # This trigger will be assigned id="2"
+      entity_id:
+        - device_tracker.paulus
+        - device_tracker.anne_therese
+      to: "home"
+```
+
+
 ## Trigger variables
 
 Similar to [script level variables](/integrations/script/#variables), `trigger_variables` will be available in trigger templates with the difference that only [limited templates](/docs/configuration/templating/#limited-templates) can  be used to pass a value to the trigger variable.