how i built heyghe, an instagram comment-to-dm tool, on cloudflare workers

i spent the last few months building heyghe, a tool that turns instagram comments into dms automatically. someone comments a keyword on your post or reel, and it dms them a link, lead form, or price list within a couple of seconds, then saves the lead. this is the build log, mostly for other devs who might touch the meta api and regret it.

the stack

• api: cloudflare workers + d1 (sqlite at the edge). the whole backend is one worker.
• auth: better-auth, running on the worker against d1. magic link, google, and passkeys.
• dashboard: react + vite spa.
• marketing site: next.js on cloudflare pages.
• billing: razorpay. email: resend. instagram: the official meta instagram api, not a scraping hack.

i wanted the whole thing on cloudflare so i wasn't paying for idle servers, and d1 was enough for the data model. no separate postgres, no redis.

the parts that were annoying

the 24 hour window. meta only lets you dm a user inside 24 hours of them interacting with you. so the "comment triggers a dm" flow is fine, but anything proactive is out. i leaned into that instead of fighting it. the tool only ever replies to people who already commented, which is also the honest, non-spammy version of this product. i wrote more about that here: is instagram dm automation safe.

webhook verification and rate limits. the comment webhook is easy to wire, harder to make reliable. you have to verify the payload, dedupe, and respect per-account send limits or you get flagged. edge functions made the latency good. getting the comment-to-dm time under about 2 seconds was mostly about not doing dumb sequential work in the handler.

better-auth on workers. smoother than i expected. magic link, passkeys, and google all ran fine against d1. the only real config pain was getting the oauth redirect uris right across local and prod.

what i'd tell another dev

if you build on the meta instagram api: read the actual policy first, respect the 24 hour window, and do not try to auto-dm strangers or new followers. it will get the account limited and it is against the rules anyway. the compliant version is also the better product.

if you're curious what it turned into, it's live at heyghe, and there's a rundown of the best instagram dm automation tools if you want to see how it compares.