POST /accounts/{account_id}/registrar/domain-check

Performs real-time, authoritative availability checks directly against domain registries. Use this endpoint to verify a domain is available before attempting registration via POST /registrations.

Important: Unlike the Search endpoint, these results are authoritative and reflect current registry status. Always check availability immediately before registration as domain status can change rapidly.

Note: This endpoint uses POST to accept a list of domains in the request body. It is a read-only operation — it does not create, modify, or reserve any domains.

Extension support

Only domains on extensions supported for programmatic registration by this API can be registered. If you check a domain on an unsupported extension, the response will include registrable: false with a reason field explaining why:

extension_not_supported_via_api — Cloudflare Registrar supports this extension in the dashboard, but it is not yet available for programmatic registration via this API. Register via https://dash.cloudflare.com/{account_id}/domains/registrations instead.
extension_not_supported — This extension is not supported by Cloudflare Registrar.
extension_disallows_registration — The extension's registry has temporarily or permanently frozen new registrations. No registrar can register domains on this extension at this time.
domain_premium — The domain is premium priced. Premium registration is not currently supported by this API.
domain_unavailable — The domain is already registered, reserved, or otherwise not available for registration on a supported extension.

The reason field is only present when registrable is false.

Behavior

Maximum 20 domains per request
Pricing is only returned for domains where registrable: true
Results are not cached; each request queries the registry

Workflow

Call this endpoint with domains the user wants to register.
For each domain where registrable: true, present pricing to the user.
If tier: premium, note that premium registration is not currently supported by this API and do not proceed to POST /registrations.
Proceed to POST /registrations only for supported non-premium domains.

Servers

https://api.cloudflare.com/client/v4

Path parameters

Name	Type	Required	Description
`account_id`	String	Yes	Cloudflare account ID. Required for all Registrar API operations.

Request headers

Name	Type	Required	Description
`Content-Type`	String	Yes	The media type of the request body. Default value: "application/json"

Request body fields

Name Type Required Description

Name	Type	Required	Description
`domains[]`	Array	Yes	List of fully qualified domain names (FQDNs) to check for availability. Each domain must include the extension. Minimum: 1 domain Maximum: 20 domains per request Domains on unsupported extensions are returned with `registrable: false` and a `reason` field Malformed domain names (e.g., missing extension) may be omitted from the response

domains[]

Array

Yes

List of fully qualified domain names (FQDNs) to check for availability. Each domain must include the extension.

Minimum: 1 domain
Maximum: 20 domains per request
Domains on unsupported extensions are returned with registrable: false and a reason field
Malformed domain names (e.g., missing extension) may be omitted from the response

How to start integrating

Add HTTP Task to your workflow definition.
Search for the API you want to integrate with and click on the name.
- This loads the API reference documentation and prepares the Http request settings.
Click Test request to test run your request to the API and see the API's response.