When someone comments on one of your posts, reels or Lives, a scenario can answer them with a DM. Instagram treats that first DM as a private reply, and it comes with one rule that shapes every comment flow: you get one message, and then the contact has to respond before you can send more.
The one-message rule
Instagram lets you send one private reply per comment. Text, a photo, a voice note, a link card: whatever the first action sends counts as that one message.
To send anything else, the contact has to interact. The moment they reply, tap a button or open a link card, Instagram opens its standard 24-hour messaging window and the rest of your flow goes through normally.
Two time limits apply:
7 days from the comment. The private reply has to go out within 7 days of the comment being posted. After that the comment can no longer be answered by DM.
24 hours for Lives. Comments made during an Instagram Live give you 24 hours, not 7 days.
Instagram created these limits to stop comment spam. They apply to every tool, not only Inrō.
What happens if a flow sends two messages in a row
If a comment-triggered scenario sends a second DM without waiting for the contact to respond, Instagram may hold or refuse it.
Inrō handles this in three ways:
A warning in the builder. When a comment scenario sends a DM and the next step is another message with nothing in between that waits for the contact, the scenario shows a suggestion on that action. The same warning is returned by the API and the MCP server when you build scenarios programmatically.
The Requested status. Contacts who don't follow you receive your private reply in their message requests rather than their main inbox. Until they accept or reply, the contact shows as Requested in Inrō and further messages can't be delivered. See Understanding Contact Status for the full list.
Existing relationships get through. If the contact already follows you or has messaged you before, the window is usually already open and follow-up messages send normally.
How to design a comment flow that gets through
Make the first DM something the contact can act on right away. The interaction is what opens the door.
Reply to the comment publicly if you like, then send one DM.
Put a tappable step first. Use a Send message with button, an Ask a question, an Ask for follow or a Conversion link action as the opening message. A tap or a reply opens the 24-hour window.
Wait before you say more. If your first message is plain text, follow it with a Wait for reply step before any further messages. Set an expiry so the flow ends cleanly if nobody answers. See Ask a Question & Wait for Reply.
Keep the rest of the flow behind that step. Links, files and follow-ups all go after the contact has responded.
The full build, with screenshots, is in Comment-to-DM: Turn Comments Into Customers.
Reaching commenters you missed
The 7-day window also works backwards. When you switch on a comment scenario, Inrō can run it on matching comments from the last 7 days that haven't triggered it yet, using the Trigger on existing comments option in the trigger settings. Details are in Triggers: The Complete Reference.
🐾 Netsuke's Tips
Lead with a question people want to answer, like "Want the link?", rather than a statement. A reply is worth more than a like here.
Contacts sitting in Requested have seen your message but haven't accepted it. A nudge from your Instagram app directly, not through Inrō, can get them to accept.
If a flow that used to work stops sending its second message, check the builder warning first. A message action was probably added before the wait step.
Don't try to work around the rule by sending the same content in one long message. Shorter first messages get more replies, and the reply is what opens everything after it.