Building automations

Send an auto-reply when someone DMs a keyword

The DM keyword trigger answers an inbound Instagram DM that matches your words: what counts as a keyword, the 24-hour window, AI fallback and your inbox.

Updated 26 October 2026

Plenty of people never comment. They open your profile and type “price?” straight into your DMs. The Someone DMs a keyword trigger answers that message automatically when it contains one of your words. It’s the same idea as a comment automation, except the fan started the conversation in your inbox.

Where to find it

Switch the Automation Studio to Advanced, then under *Account-wide* pick Someone DMs a keyword (“An inbound DM matches a keyword → auto-reply.”). Like story triggers it isn’t tied to a post: it watches every DM your account receives. For the basics of the studio see Build your first automation.

What counts as a keyword DM

Dartzo sorts each incoming message before it looks for a keyword, so these cases don’t get mixed up:

What the fan sends	What Dartzo does
A typed text message	Checks it against your DM keyword rules. This is the one that can fire this trigger.
A reply to one of your stories	Treated as a story reply, not a DM keyword. See Story replies and mentions.
A tap on one of your buttons or quick replies	Treated as a button tap that continues a conversation you already started. A tap never fires a keyword rule, even if the button’s label contains your keyword.
A photo, voice note, sticker or shared reel with no words	Nothing to match, so no automation fires. It still counts as the fan getting in touch, which keeps the 24-hour window open.

Words are matched the same way as on comments: capital letters don’t matter, and each automation has a match type. New automations built in the web studio use Contains, which means the keyword can appear anywhere in the message. Read Keyword match modes before choosing short words. A keyword like hi also sits inside “this” and “which”.

Two alternatives to keywords: Reply to any message answers every typed DM, and Exclude keywords (Advanced, under *Settings* in the calm view) stops a rule from firing when a message contains words you list. A message with an excluded word never triggers that rule, whatever else it says.

“Reply to any message” answers everything

A rule with no keywords matches every typed DM, so every one gets the same reply, including “thanks!” and “ok”. It also takes priority over the AI fallback below, because the AI only speaks when no rule matched. Use it for a simple away message, not as a catch-all next to other rules without checking which one wins.

The 24-hour window

Instagram lets a business message someone for 24 hours after that person last messaged it. The fan’s DM is what opens that window, so a DM keyword automation is always replying inside it. A few things follow:

The window opens on every message they send, not only the ones that match a rule. A fan who writes “thanks!” keeps the conversation open for 24 hours from that message.
Dartzo’s deadline is 18 hours. It subtracts a 6-hour safety margin from Instagram’s 24, so a send never starts at the edge of a closing window.
If the DM can’t go out immediately (a busy moment, a retry) it waits in the queue and is sent before the deadline. If the deadline passes first, it is marked as expired in your delivery log with the reason. It doesn’t vanish.
Speed: up to 100 messages per second for DM triggers. They don’t use the hourly allowance that applies to comment replies.
One reply per person per automation per 24 hours. A fan who sends your keyword four times gets one DM from that automation. Their messages still reach your inbox.

Because the conversation is open, the first DM can carry buttons straight away. See Buttons and links. The full list of windows and caps is in Limits and windows.

When no rule matches: the AI fallback

A DM that matches no keyword rule gets no automated reply, unless you’ve turned on AI replies. In the studio this is the AI reply (FAQ) switch (“Answers when no keyword matches”), found in Advanced or under *Settings* in the calm view. When it’s on you choose When AI answers:

Setting	What it means
On no match	The AI steps in only when none of your keyword rules matched.
Every message	The AI is consulted on every inbound message, but keyword rules still win first.

The AI answers only from your knowledge base, never a made-up answer. When it can’t answer, the fan gets your fallback message instead.
It uses AI credits and needs an AI route set up. With none, the switch shows “Setup pending” and stays off. See AI replies and AI credits.
The switch lives on a DM keyword rule. The AI looks for an active DM keyword automation with AI turned on. If you only have a comment automation with AI on, it won’t answer DMs.
One AI reply per person per 24 hours, the same rule as keyword rules. A fan sending the same unanswerable question five times gets one reply.

How it shows up in your inbox

The conversation stays in your Instagram DMs, with the automated reply in the same thread, so you can take over by hand there while the window is open. Failed sends are recorded in your delivery log with their reason, so you never mistake a person nobody reached for a conversation that’s waiting.

A worked example

A salon in Bengaluru wants bookings from people who message first. The owner builds one rule: trigger Someone DMs a keyword, keywords BOOK and PRICE, with a Link button to the booking page.

Sent when someone DMs “price for haircut?” or “want to book”.

Hi {{first_name}}! 💇‍♀️ Haircut from ₹499, colour from ₹1,800.
Pick a slot that suits you here 👇
{{link}}

Anyone writing “hi” or “are you open Sunday?” matches nothing, so the owner’s inbox shows the message and she answers it herself, or the AI fallback does if she has turned it on.

Does a DM keyword automation need a post?

No. It is account-wide: it watches all the DMs your Instagram account receives, so nothing is attached to a post, reel or story.

Why didn’t my DM keyword rule fire when I tested it?

The usual causes are a rule that is paused or still a draft, a message that was a button tap or a story reply rather than typed text, an excluded word in the message, or an automation that already replied to you in the last 24 hours. Remember that your own account’s messages never trigger anything.

Can the AI answer DMs and keyword rules answer the rest?

Yes. Keep your keyword rules for the questions you want to answer word for word, and turn on AI reply on one of those rules for everything else. Keyword rules are checked first, and the AI only answers a message that no rule matched.

How long can I wait before replying?

Instagram allows 24 hours after the fan’s last message. Dartzo sends as soon as it can and treats 18 hours as its own cut-off. A message marked expired can still be answered by hand from your inbox for as long as Instagram’s window is open.