Infrastructure · Coolify

Branded temp links for every app on Coolify

Turn Coolify's ugly auto-generated URLs into short, on-brand links like replyee.t.boommedia.us — one DNS record, one Coolify field, applies to all 15 SaaS apps.

Droplet 159.65.235.140
Wildcard *.t.boommedia.us
Cost $0
Time ~10 min

What actually happens when someone opens a link

1 · Browser
Asks DNS: where is
abc123.t.boommedia.us
2 · DNS wildcard
*.t record answers with your droplet IP
159.65.235.140
3 · Coolify (Traefik)
Matches the host to the right app + auto-issues TLS
4 · Your app
Served over HTTPS on a clean branded URL

Right now, an app deployed without a domain falls back to Coolify's default — something like a1b2c3.159.65.235.140.sslip.io. It works, but it's long, unbrandable, and leaks the raw IP. The fix is to give Coolify a wildcard domain to build links from. You do it once at the server level and every app inherits it.

Step 1 — Add the DNS records

In whatever manages boommedia.us DNS (the same place db.boommedia.us lives), add two A records pointing at the droplet.

TypeName / HostValue
A*.t159.65.235.140wildcard
At159.65.235.140root
Registrar quirk: some panels want just the host part (*.t), others want the full *.t.boommedia.us. Both mean the same thing. Leave any proxy / “orange cloud” CDN toggle OFF — this must resolve straight to the IP so Coolify can do the TLS handshake.
Why two records? The *.t wildcard covers every generated subdomain (abc123.t…, replyee.t…). The bare t record covers the root itself, so nothing 404s if it's ever hit directly.

Step 2 — Point Coolify at the wildcard

1

Open your server's settings

Coolify → Serversyour dropletConfiguration / General

You're setting this at the server level, not per-app — that's why it applies to all 15 apps at once.

2

Fill the “Wildcard Domain” field

https://t.boommedia.us
Keep the https:// prefix. That's the signal that tells Coolify to auto-request a Let's Encrypt certificate for every host it generates. Drop it and you'll get plain HTTP links.
3

Save

No restart needed. New domains generated from now on use the wildcard. Existing apps keep whatever domain they already have.

Step 3 — Use it on an app

Two ways, per app, under its Domains section:

A

Auto-generate (fastest)

Click Generate Domain → Coolify hands you a random branded host with TLS already sorted:

https://a1b2c3d4.t.boommedia.us
B

Name it yourself (nicer for sharing)

Type a memorable host in the Domains field — cleaner than a random hash when you're sending previews to a client:

https://replyee.t.boommedia.us
https://displayee.t.boommedia.us
https://rewardee.t.boommedia.us

Step 4 — Verify it works

Before trusting a link, confirm DNS resolves. Run this from anywhere (your Mac, the droplet, wherever):

# should print the droplet IP
dig +short foo.t.boommedia.us
159.65.235.140
Green light: if that returns 159.65.235.140 for any made-up subdomain, the wildcard is live and Coolify can issue certs on demand. If it returns nothing, DNS hasn't propagated yet — give it a few minutes (up to ~30 for some providers).

No dig on Windows? Use nslookup foo.t.boommedia.us in PowerShell instead — same idea.

Details & edge cases

The things that trip people up.

Do I need a wildcard SSL certificate?
No. Coolify issues a separate Let's Encrypt cert per generated host using the HTTP-01 challenge, which only needs the hostname to resolve to the server. The wildcard is in DNS (so any label resolves), not in the cert. You'd only need a wildcard cert if you used the DNS-01 challenge — you don't here.
Why the label “t” — can I use something else?
Purely a naming choice — t = “temp” and is the shortest sensible label. Swap it for on (echoes your .online app domains), link, go, or app. Just use the same word in both the DNS record and the Coolify field. Links become x.on.boommedia.us, etc.
Does this touch my production domains?
No. Production apps keep their real domains (replyee.online, displayee.online…). The wildcard only fills in the blank when an app has no explicit domain — i.e. previews, staging, and quick shares. Both can coexist on the same app.
Is exposing the droplet IP in DNS a security risk?
The IP is already public the moment anything is served from it — the current sslip.io fallback literally puts the IP in the URL. A wildcard A record is no different from any normal DNS record. If you later want the IP hidden, that's a separate project (put Cloudflare proxy in front) and unrelated to this setup.
A generated link shows a cert warning — what now?
Almost always DNS hadn't propagated when Coolify first tried to issue the cert, so Let's Encrypt failed. Fix the DNS (confirm with dig), then in the app's Domains section re-save / redeploy to retry issuance. Also make sure ports 80 and 443 are open on the droplet firewall — 80 is required for the HTTP-01 challenge.