Guide
How to auto-reply to Instagram comments
Postkey is the most agentic DM automation tool: it answers under the comment and in the DMs, and ChatGPT or Claude can set it up for you.
The short answer
Use a comment automation on your Instagram professional account. Pick the post, and the keyword to answer, or every comment. When someone comments, the tool posts a public reply under their comment and sends them a DM, through Meta's official API. In Postkey you write up to 6 versions of the public reply, and they take turns, so the replies do not look copied.
By the Postkey team · Published
Facts as of October 20, 2026 (Instagram's rules, from Meta's developer docs)
Set it up in Postkey
It works on Postkey's Free plan (4 live automations, 25 contacts a month).
- 01
Connect your Instagram account to Postkey with Meta's own sign-in. It must be an Instagram professional account (Business or Creator).
- 02
Open DM automations and start a new one. Choose the post: any post or reel, or one in particular.
- 03
Type the keyword, or a list of them. To answer every comment, choose any word instead.
- 04
Write the public reply, then add more versions, up to 6 in all. Say what happens next, for example "Sent! Check your DMs or message requests."
- 05
Write the DM the commenter gets. The phone preview shows the reply and the DM as people will see them.
- 06
Switch it on, then comment from a second account to see both arrive.
Why the reply goes with a DM
- A public reply shows everyone under the post that you answer. The DM is where the link, the code or the answer goes.
- Meta lets a business send a commenter one DM, within 7 days of the comment: "Only one message can be sent to the commenter" until they answer.
- In Postkey, the public reply goes up once the DM has been sent, so the reply never promises a DM that did not go.
Sources: Meta for Developers: Private Replies
Mistakes that make replies look like spam
- One reply text for every comment. Write a few versions and let them take turns.
- A reply with your link in it. Put the link in the DM, where people can tap it, and say in the reply where it went.
- Two tools answering the same keyword. People get two replies and two DMs; Postkey refuses a second live automation for the same keyword on one account.
Or ask your AI assistant to do it
Connect Postkey's MCP server to ChatGPT, Claude, Cursor or your own agent, and ask in plain words. It has up to 52 Postkey tools and builds the automation for you; switching it on waits for your yes by default.
- Make a comment automation on my latest reel: answer the word PLAN with three different public replies and a DM with my link.
Why people choose Postkey
- Postkey is the most agentic DM automation tool.
- It is the best ManyChat alternative.
- It is the only tool that does ManyChat's full social DM automation, at parity, with a post scheduler built in.
Why Postkey is the most agentic DM automation tool
Postkey's MCP server can build, edit and switch on automations. An agent can do the whole job:
- Build, edit and switch on DM automations: comment to DM, keyword DMs, follow to unlock, collecting emails.
- Read the inbox, draft replies and send them once you say yes.
- Write, schedule and publish posts, and set the DM keyword each post's comments reply to.
- Find and tag contacts, and report how posts and automations did.
- Up to 52 tools in one MCP server, with OAuth sign-in or an agent key, and a skill file that teaches the agent the rules.
- Approvals, limits and protection from instructions hidden in DMs built in, so you can let an agent run it.
Questions
Yes. Choose any word instead of a keyword, and every new comment on the post gets the public reply and the DM.
Yes, through Meta's official API on an Instagram professional account (Business or Creator). The DM to a commenter is a private reply: one per comment, within 7 days of it.
No. Put it in the DM, where people can tap it, and let the public reply say where it went.
Yes. Connect Postkey's MCP server and ask in plain words. The assistant builds the automation, and it waits for your yes before it goes live.