What is Instagram comment-to-DM automation?

It is a workflow that watches for comments on a specific Instagram post and automatically sends the commenter a direct message, usually containing a link or a piece of content they asked for in the comment. It is commonly used to convert post engagement into leads.

Why run this on n8n instead of ManyChat?

ManyChat charges a recurring SaaS fee and limits customization to what its workflow builder exposes. A self-hosted n8n workflow costs the price of a small server, runs on the same Meta Graph API webhook underneath, and can be extended with any logic n8n supports, including calling an AI model to write the reply.

Does this require the Instagram Graph API?

Yes. The workflow subscribes to comment webhooks through a Meta app connected to the Instagram professional account, then calls the Send API to deliver the DM once a comment matches the configured trigger.

What actually breaks when you self-host this?

Token expiry is the most common failure: Meta access tokens need periodic renewal, and a workflow that silently stops sending DMs because of an expired token is the single most common production incident with this setup.

Instagram Comment-to-DM Automation with n8n

ManyChat and similar SaaS tools handle Instagram comment-to-DM automation for a monthly fee and a closed workflow builder. This guide documents the architecture of a production n8n workflow that does the same job self-hosted: the webhook trigger, comment matching logic, and the DM send step, plus what actually breaks when you run it yourself.