Can I vibecode Soccial AI?

Build a self-hosted Instagram DM auto-responder for my own Instagram professional account, in this empty folder.

Stack: Node 22 + Hono + better-sqlite3 + the Anthropic SDK (claude-sonnet-5). One small server, no frontend. Secrets in .env: IG_ACCESS_TOKEN, IG_ACCOUNT_ID, META_APP_SECRET, META_VERIFY_TOKEN, ANTHROPIC_API_KEY.

Endpoints:
- GET /webhook: Meta's hub.challenge verification handshake.
- POST /webhook: verify X-Hub-Signature-256 with META_APP_SECRET, ACK 200 immediately, process async.

On each incoming DM: skip echoes of my own outbound messages (is_echo); dedupe by message id in SQLite; load the last 10 messages of that conversation from SQLite as context; generate a reply with Claude using the editable system prompt in persona.md; send it via POST https://graph.instagram.com/v23.0/me/messages with recipient.id set to the sender's IGSID; log both sides to SQLite.

Guardrails: never reply twice to the same message id; hard cap of one auto-reply per user per two minutes; if the model's reply contains the token HUMAN, send nothing and log it for me instead.

Write a README that walks through the Meta side, which is the actual hard part: create a Meta app, add the Instagram API with Instagram Login, generate a long-lived access token for my account, subscribe the app to the messages webhook field, and expose this server with a Cloudflare Tunnel. Note plainly that in development mode this works only for my own account, and that is the point.

Deliberately out of scope: comment automation, multiple accounts, any CRM, Shopify or calendar integrations, and Meta App Review.