Domains

A form’s share link normally lives on the fomr host. With a custom domain, it can live on your own domain or on a fomr subdomain, under a path you choose. Domains are added and verified in the app, as described in Custom domains. The Platform API lists them and binds them to forms.

Operation	What it does	Permission
GET /v1/domains	Lists the domains of the organization.	domains:read
PUT /v1/forms/{form_public_id}/domain	Sets the custom domain and slug of the share link.	forms:write and domains:write
DELETE /v1/forms/{form_public_id}/domain	Removes the custom domain from the share link.	forms:write and domains:write

Listing domains

curl -s -H "Authorization: Bearer $FOMR_TOKEN" \
  https://platform.fomr.io/v1/domains

GET /v1/domains

{
  "data": [
    {
      "host": "acme.fomr.io",
      "status": "verified",
      "is_active": true,
      "is_fomr_subdomain": true,
      "created_at": "2026-09-14T08:30:00.000Z"
    },
    {
      "host": "forms.acme.com",
      "status": "verified",
      "is_active": true,
      "is_fomr_subdomain": false,
      "created_at": "2026-09-20T12:00:00.000Z"
    },
    {
      "host": "events.acme.com",
      "status": "pending",
      "is_active": true,
      "is_fomr_subdomain": false,
      "created_at": "2026-10-20T16:45:00.000Z"
    }
  ]
}

Every field of a domain is listed in the response of List domains.

Only a domain whose status is verified and whose is_active is true can be bound to a form. A domain turns inactive when the organization’s plan no longer includes custom domains.

Setting a form’s domain

curl -s -X PUT "https://platform.fomr.io/v1/forms/Ev3ntReg01/domain" \
  -H "Authorization: Bearer $FOMR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"domain":"forms.acme.com","slug":"/register"}'

The response is the form resource. Its domain block shows the binding, and urls.share uses it once a version is published.

• domain is the host from GET /v1/domains, matched without regard to case.
• slug is the path after the host. Trailing slashes are removed and a leading slash is added, the same normalization the Share link tab applies, so register/ is stored as /register. Send / to serve the form at the root of the domain. Left out, the slug is /{form_public_id}.
• A slug is unique per domain. A slug another form already uses on the same domain is 400 INVALID_INPUT at slug.
• Sending the current binding changes nothing and answers 200, so the call is safe to retry.
• Setting a domain replaces the previous one. A form has at most one custom domain.

Refusal	Answer
The organization’s plan has no custom domains	402 PRO_FEATURE_REQUIRED with feature: "domains"
The host is unknown, not verified, or inactive	400 INVALID_INPUT at domain
The slug holds characters other than letters, digits, -, _, and /	400 INVALID_INPUT at slug
The resource is a Private Template, which has no share link	400 INVALID_INPUT at domain
The form is archived	409 FORM_ARCHIVED
The member lacks domains:write	403 FORBIDDEN

The binding is stored the way the app stores it, so the editor shows it at once and publishing checks it like any other custom domain.

Removing a form’s domain

DELETE /v1/forms/{form_public_id}/domain removes the binding and answers the form resource, which uses the fomr link again. A form without a custom domain answers 200 and writes nothing. Removing a domain needs no plan feature.