Triggers are the door into a flow. This guide covers what each of the ten types waits for, which one wins when several match the same event, and which ones cut into a conversation already in progress.
You built the automation, wrote the message, added the buttons — and nothing happens, because you never said when the flow should start. That is exactly what a trigger says: which event sets this flow in motion. This guide shows where triggers live in the panel, what each of the ten types waits for, and what decides the winner when several of them match at once.
💡 To add a trigger, open the automation, go to the Flow tab, click the When… box on the canvas and use Add trigger in the panel on the right. That box is the flow's start step; it cannot be deleted and you cannot add a second one.
In this article you will find:
Where triggers live
The ten trigger types and the events they wait for
When several triggers match the same event
Which triggers cut into a running conversation
What happens when an event has no trigger of its own
Testing triggers before you publish
Limits and known issues
Where triggers live
Triggers are not steps; they are filters that sit inside the start step. They send nothing themselves and change nothing about the person. Their only job is to answer "does this event match me?". The first step of the flow sends the message.
To add one:
Open the automation from the automations list.
Click the box labelled When… on the Flow tab.
Press Add trigger in the panel on the right.
Pick the type from the list. The list is filtered by the account's channel: a type with no counterpart never appears.
Fill in the fields that belong to that type (words, post, tag, date…).
Press Publish at the top right. Until you publish, the trigger does nothing live.
Every trigger also has a Channel choice. It only appears when more than one channel is connected to the account; on single-channel accounts it is hidden and the trigger already runs on that channel. With several channels you can leave All channels or pick one account.
A start step holds up to 20 triggers, and all of them start the same flow. A flow with no trigger cannot be published; the pre-publish check reports "Add at least one trigger."
The ten trigger types and the events they wait for
The types fall into three families by the event they wait for. Each one has its own article.
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Events that arrive as a message
Keyword — When the person writes one of the words you chose.
Any message — On every message that arrives while the person has no open session.
Story reply — When the person replies to your story.
Story mention — When the person tags your account in their own story.
Post share — When the person sends you a post or reel in DM.
Events that arrive from the comment box
Post comment — On comments under posts, reels or live videos.
Mention — When someone tags you on somebody else's post or comment.
Events that wait for no message
Link / ad — When the chat starts from an ad, a short link or a QR code.
Date and time — On a clock, without waiting for the person to write at all.
Post comment, Mention, Story reply, Story mention and Post share exist on Instagram only. WhatsApp has no posts, stories or comments, so those events never reach the queue and the type list hides them on a WhatsApp account. An old choice saved in a flow is not deleted: the pre-publish check warns that "Comment, mention, story and share triggers only work on Instagram" and leaves the decision to you.
When several triggers match the same event
One event can match triggers in several different automations at once. A comment saying "what is the price" on your pricing post matches both "every comment on this post" and "all posts + the word price". Only one flow starts, and a score decides which: the narrower one wins.
The score adds up from three parts:
Choosing a specific target: 10 points. Picking one post on a comment trigger, writing one link tag (ref) on a link trigger. This is the heaviest narrowing there is.
Match mode: 1–4 points. Exact match 4, whole word 3, starts with 2, contains 1. The detail is in match modes.
Narrowing the source: 1 point. Only post comments or only live video; only ads, only short links or only QR codes.
In the example above "every comment on this post" scores 10 and "all posts + contains" scores 1, so the first one wins. When scores tie, the trigger created first wins.
⚠️ Note: the scoring runs across automations too. Putting the same word in two automations does not run both; only the higher score starts. Splitting words between automations on purpose is easier than hunting down which one ran.
Which triggers cut into a running conversation
The person may have a session half-finished: we may be waiting for them to answer a question. Some triggers cut that session, others do not.
Explicit triggers cut the running session and start their own flow: keyword, post comment, mention, story reply, story mention, post share, link/ad. The reasoning is that someone arriving through a new door — a new comment, a new ad — should not be left stranded in the middle of an old conversation.
Any message and Default reply never cut. They run only while the person has no open session; text that arrives during a session goes to that session.
On an incoming message the engine works through this order:
If the person tapped a button, triggers are not consulted at all; the session continues down that button's branch.
The highest-scoring explicit trigger is looked for. If one is found, the person's running sessions are closed and the new flow starts.
If there is no explicit trigger and the person has a session waiting for an answer, the text goes to that session.
If the person has another open session (a wait, a handover pause), no new automation starts.
If the person is completely idle, Any message is tried.
If that fails too, Default reply is tried.
There are two exceptions. Turning off A new keyword can interrupt this automation on the automation's Settings tab protects that automation: a keyword arriving while the person is expected to reply is ignored and the text goes to the flow instead. This is recommended for flows that collect data. The second exception is Mention, where the re-entry rule never applies because the person's identity is unknown.
What happens when an event has no trigger of its own
Story replies, post shares and link/ad chats arrive with the person's own message. If no trigger matches those events, the message is reconsidered as an ordinary message: keyword, any message and default reply triggers are tried.
In practice that means someone who replies to your story with the word "price" lands in your pricing flow even if you have no story reply trigger at all.
Post comment is the exception. A comment is not a conversation: if no comment trigger matches, the text of the comment is not handed to the person's running DM flow and nothing happens. Story mention does not fall back either.
Testing triggers before you publish
The simulator on the automation's Test tab lets you try triggers while the flow is still a draft. Nothing is sent to the real channel.
Open the Test tab.
Pick the account's channel from the Channel list above the phone frame.
Pick the event you want to try from the Event list next to it. The list shows the event triggers your flow actually contains; if you have no trigger beyond message-based ones, the list does not appear.
For events that carry text (message, keyword, comment, story reply) type the text into the box and press Send. For events without text, send directly.
Read the log on the right. When nothing matched you see the note "This message did not match any trigger."
The simulator and the engine use the same matching rule, so text that matches in the simulator matches live as well. To try it on a real channel, use Try on a real channel on the same tab and choose someone who wrote in the last 24 hours; that session is marked as a test and stays out of your statistics.
Limits and known issues
A start step holds at most 20 triggers.
A keyword, comment or story reply trigger holds at most 30 words, and each word is at most 100 characters.
If Default reply is added twice to the same flow the pre-publish check warns you; the second one has no effect.
Comment, mention, story and share events come from Instagram only. This is a limit on Meta's side: WhatsApp has no equivalent of those events.
If your plan does not cover a trigger type the flow stays published, but the session stops at that step and the pre-publish check shows a "Your plan does not include…" warning.
A trigger only runs while the automation is Published. Triggers on a draft or a switched-off automation are never tried.
If the flow still does not start after you set the triggers up, see the automation never starts guide or contact our Support team.