DNS Provisioning

Records to configure for useatrium.me via your registrar (Namecheap, Cloudflare, etc.).

Required records

Type	Host	Value / Target	TTL	Notes
CNAME	verify	cname.vercel-dns.com	300	Production frontend
CNAME	verify-staging	cname.vercel-dns.com	300	Staging preview
A	codex	`<DROPLET_IP>`	300	Caddy auto-TLS → :3000
A	tablet	`<DROPLET_IP>`	300	Caddy auto-TLS → :3001
CNAME	status	atrium-protocol.github.io	300	Upptime status page
A	@	Vercel IP (76.76.21.21)	300	Root domain redirect
TXT	@	`v=spf1 include:_spf.google.com ~all`	3600	Email (if using Google Workspace)

Replace <DROPLET_IP> with the IP printed by scripts/provision-do-droplet.sh.

Step-by-step (Namecheap)

Log in → Domain List → useatrium.me → Advanced DNS.
Add each record from the table above.
Save all changes.

Vercel custom domains

After DNS records propagate:

Vercel dashboard → Project (atrium-verify) → Settings → Domains.
Add verify.useatrium.me → assign to Production.
Add verify-staging.useatrium.me → assign to Preview (branch: staging).
Vercel will verify DNS automatically.

Verification

# Each should resolve correctly
nslookup verify.useatrium.me
nslookup codex.useatrium.me
nslookup tablet.useatrium.me
nslookup status.useatrium.me

# TLS check (after Caddy is running on droplet)
curl -I https://codex.useatrium.me/healthz
curl -I https://tablet.useatrium.me/healthz

Caddyfile reference

The droplet runs Caddy as reverse proxy. See services/codex/Caddyfile and runbooks/caddy-on-droplet.md for installation.

Combined Caddyfile installed at /etc/caddy/Caddyfile:

codex.useatrium.me {
  reverse_proxy localhost:3000
}

tablet.useatrium.me {
  reverse_proxy localhost:3001
}

Caddy handles TLS certificate provisioning via Let's Encrypt ACME automatically.