Custom domains

Before you start#

• Custom domains are part of the Business plan (one domain) and the Enterprise plan (up to 3 domains).
• You need access to the DNS settings of the domain, at your registrar or DNS host.
• Use a subdomain such as go.acme.com or link.acme.com. It needs one CNAME record and leaves your website on acme.com untouched.
• A root domain such as acme.com works only if your DNS provider supports CNAME flattening or an ALIAS/ANAME record on the root, as Cloudflare, DNSimple and Namecheap do. Route 53 and GoDaddy cannot point the root to another hostname, so use a subdomain there.

Set up a domain#

1. 1

   Add the hostname

   In the dashboard, open Custom domains from Settings or the Links page and click Add domain. Enter only the hostname, such as go.acme.com, without https:// or a path.

2. 2

   Add the CNAME record

   Appy shows the record to add: type CNAME, the name (for go.acme.com that is go) and the value cname.appy.to. Add it at your DNS provider exactly as shown.

3. 3

   Wait for the check

   Appy checks the record every minute for the first hour, then every 10 minutes. You can also click Check now. Most providers publish a new record within minutes; a long TTL on an old record can delay it.

4. 4

   Certificate and live

   Once the record points to Appy, the HTTPS certificate is issued and renewed automatically. The status turns Active and https://go.acme.com/<slug> opens the same link as https://appy.to/<slug>.

Adding the record at common DNS providers#

Delete any existing A, AAAA or CNAME record for the same name first; a name can hold only one CNAME and nothing else.

Statuses#

Common errors and fixes#

Default domain#

Make one active domain the default. The dashboard then shows and copies short links on it, QR codes encode it, and the REST API returns it in the url field of links. Every link keeps working on every active domain of your account and on appy.to, so changing the default never breaks a URL you already shared or printed.

The root and unknown paths#

Set a root redirect URL, usually your website, for visits to https://go.acme.com/ and to paths that are not one of your links. Without it, those visits see a plain not-found page without Appy branding. Links of other Appy accounts never open on your domain.

App links on your domain (Enterprise)#

On the Enterprise plan you can assign an active domain to one of your SDK apps. Appy then serves the app’s apple-app-site-association and assetlinks.json on the domain, so Universal Links and Android App Links open the app from go.acme.com just as they do from your app subdomain.

1. 1

   Assign the domain

   On the domain page, choose the app under Use for app links. You can also send appId with PATCH /v1/domains/{id}.

2. 2

   iOS

   Add applinks:go.acme.com to Associated Domains, next to your existing entry.

3. 3

   Android

   Add <data android:host="go.acme.com" /> to the intent filter with android:autoVerify="true".

4. 4

   SDK

   Add the domain to linkDomains. Put it first if links built in the app should use it.

Appy.configure(AppyConfiguration(publishableKey: "appy_pk_live_...", linkDomains: ["go.acme.com", "acme.appy.to"]))

Apple and Google cache these files. A new domain can take up to a day to open the app on devices that already have it installed; reinstalling the app refreshes the cache. See the iOS and Android guides for the full setup.

Removing a domain or changing plans#

• Removing a domain stops it right away: links on that hostname no longer open, while the same links keep working on appy.to and on your other domains. If the domain is printed on QR codes, packaging or posters, keep it.
• After removing a domain you can delete its CNAME record. Removing frees the slot in your plan, and you can add the same hostname again later.
• If the account leaves the Business or Enterprise plan, its domains keep answering: every request is redirected with 301 to the same path on appy.to for as long as the CNAME record points to Appy, so printed QR codes and shared links keep working.

Managing domains with the API#

Every step of the dashboard is also available in the REST API with a secret key, on the Business and Enterprise plans. The MCP server has a read-only list_domains tool.

curl https://api.appy.to/v1/domains \
  -H "Authorization: Bearer $APPY_SECRET_KEY" \
  -H "Content-Type: application/json" \
  -d '{"hostname": "go.acme.com", "rootRedirectUrl": "https://acme.com"}'

{
  "id": "5b1e9c2a-7d4f-4e8a-b3c6-0f2d8a6e4c19",
  "hostname": "go.acme.com",
  "status": "pending",
  "isDefault": false,
  "rootRedirectUrl": "https://acme.com",
  "appId": null,
  "dns": {
    "type": "CNAME",
    "name": "go",
    "host": "go.acme.com",
    "value": "cname.appy.to",
    "apex": false,
    "note": null
  },
  "verification": [],
  "lastError": null,
  "lastCheckedAt": null,
  "verifiedAt": null,
  "createdAt": "2026-10-01T09:00:00Z",
  "updatedAt": "2026-10-01T09:00:00Z"
}

Errors follow the usual format: validation_failed for a hostname or URL that cannot be used, conflict when the hostname is already in use, limit_reached when every domain slot of the plan is taken, and plan_required below Business.