> ## Documentation Index > Fetch the complete documentation index at: https://cactal.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # Add a custom domain > Claims `hostname` for this website and registers it with the Cactal edge. Custom domains must first be enabled for the website (`websiteDomains.setEnabled`, owner-only — enabling is the billing moment); the request fails with 403 `custom_domains_disabled` otherwise. Adding or removing domains on an enabled website never changes billing. The domain is created in `pending_dns` status, and the returned `dnsRecords` list exactly what to create at your DNS provider: an ownership TXT record on `_cactal.` plus a routing record (a CNAME for subdomains or an A record for apex domains). Hostnames must be lowercase ASCII domains (not IP addresses or Cactal platform hosts), each website can have at most 10 custom domains, and a hostname can be claimed by only one website; claims that never verify expire after 7 days. After creating the records, call the verify endpoint or wait for the automatic re-checks. ## OpenAPI ````yaml /api-reference/openapi.json post /websites/{websiteId}/domains openapi: 3.1.0 info: title: Cactal API version: 1.0.0 description: >- The Cactal public API. Create, edit, publish, and operate websites programmatically. Authenticate every request with an API key sent as `Authorization: Bearer `. servers: - url: https://api.cactal.ai/v1 security: - apiKey: [] tags: - name: Documentation description: >- Search and read the Cactal product documentation for concepts, guides, agent workflows, platform behavior, and API operations. - name: Feedback description: >- Submit free-form product feedback from users and agents to the Cactal feedback inbox. - name: Websites description: >- Create and manage websites — the top-level resource that owns source code, content, assets, domains, and analytics. - name: Website editors description: >- Grant, list, and revoke website-scoped editor access, and invite collaborators to a single website by email. - name: API keys description: >- Create, scope, rotate, and revoke the API keys that authenticate programmatic and agent access. - name: Source code description: >- Read and edit the framework source files of a website draft. Mutations require an edit lease. - name: Publishing description: Validate, build, publish, and roll back website versions. - name: CMS collections description: >- Define the content model: collections of structured content owned by a website. - name: CMS fields description: Manage the typed fields that make up a collection schema. - name: CMS items description: >- Create, query, publish, and organize the content entries inside a collection. - name: Domains description: >- Manage platform subdomains and custom domains, including DNS verification and the primary domain. - name: Assets description: Upload and manage website files and images served from the Cactal CDN. - name: Media generation description: >- Generate reference-guided website images that are stored as ordinary Cactal CDN assets. - name: Project Context description: >- Upload private durable reference material that the website agent can search, read, and inspect. - name: Analytics description: >- Read first-party traffic analytics for a website and export datasets as CSV. - name: Organizations description: Manage organizations, members, and organization-wide invitations. - name: Audit log description: >- Read the immutable record of actions performed in an organization by users and API keys. - name: Billing description: >- Read billing state and manage plans, site capacity, and prepaid usage balance. Every billing operation requires the organization owner role, which API keys cannot hold — today these operations are performed from the dashboard, return 403 for API-key callers, and are hidden from MCP tool lists. paths: /websites/{websiteId}/domains: post: tags: - Domains summary: Add a custom domain description: >- Claims `hostname` for this website and registers it with the Cactal edge. Custom domains must first be enabled for the website (`websiteDomains.setEnabled`, owner-only — enabling is the billing moment); the request fails with 403 `custom_domains_disabled` otherwise. Adding or removing domains on an enabled website never changes billing. The domain is created in `pending_dns` status, and the returned `dnsRecords` list exactly what to create at your DNS provider: an ownership TXT record on `_cactal.` plus a routing record (a CNAME for subdomains or an A record for apex domains). Hostnames must be lowercase ASCII domains (not IP addresses or Cactal platform hosts), each website can have at most 10 custom domains, and a hostname can be claimed by only one website; claims that never verify expire after 7 days. After creating the records, call the verify endpoint or wait for the automatic re-checks. operationId: websiteDomains.createCustomDomain parameters: - name: websiteId in: path required: true schema: type: string minLength: 1 requestBody: required: true content: application/json: schema: type: object properties: hostname: type: string minLength: 1 required: - hostname responses: '200': description: >- The created domain in `pending_dns` status. Next: create the `dnsRecords` at your DNS provider, then call `websiteDomains.verifyCustomDomain`. content: application/json: schema: type: object properties: id: type: string description: Unique domain id. hostname: type: string description: >- Fully-qualified lowercase hostname, e.g. `blog.example.com`. status: type: string enum: - pending_dns - pending_verification - active - failed - removing - suspended description: >- `pending_dns`: waiting for the required DNS records; `pending_verification`: DNS found, waiting for the edge host to become ready; `active`: serving traffic; `failed`: verification failed (see `failureMessage`); `removing`: being deregistered from the edge; `suspended`: disabled by Cactal trust & safety. Platform subdomains are always `active`. kind: type: string enum: - platform_subdomain - custom description: >- Every website automatically gets one `platform_subdomain`; `custom` domains are added through this API. isPrimary: type: boolean description: >- Whether this is the canonical custom domain that published traffic redirects to. Always `false` for platform subdomains. dnsRecords: type: array items: type: object properties: type: type: string enum: - TXT - CNAME - A description: DNS record type to create. name: type: string description: Fully-qualified name (host) to create the record on. value: type: string description: Exact value the record must resolve to. purpose: type: string enum: - ownership - routing description: >- `ownership` records prove control of the hostname (TXT); `routing` records point traffic at the Cactal edge (CNAME for subdomains, A for apex domains). required: - type - name - value - purpose additionalProperties: false description: >- DNS records the domain owner must create for verification to succeed. Empty for platform subdomains. failureMessage: anyOf: - type: string - type: 'null' description: >- What the most recent verification check found wrong, including whether ownership is missing, the hostname is unreachable, or traffic reaches a service other than Cactal. `null` when nothing is wrong. lastCheckedAt: anyOf: - type: string format: date-time - type: 'null' description: >- When DNS and edge status were last checked. `null` before the first check. createdAt: description: When the domain record was created. type: string format: date-time required: - id - hostname - status - kind - isPrimary - dnsRecords - failureMessage - lastCheckedAt - createdAt additionalProperties: false '400': description: >- Validation failed. The response `message` names the first invalid field. content: application/json: schema: $ref: '#/components/schemas/ServiceError' '401': description: Missing, invalid, expired, or revoked API key. content: application/json: schema: $ref: '#/components/schemas/ServiceError' '403': description: The authenticated principal lacks the required capability. content: application/json: schema: $ref: '#/components/schemas/ServiceError' '404': description: >- The resource does not exist or is outside the principal’s access scope. content: application/json: schema: $ref: '#/components/schemas/ServiceError' '409': description: The request conflicts with the current state of the resource. content: application/json: schema: $ref: '#/components/schemas/ServiceError' '429': description: >- Rate limit exceeded. Retry after the number of seconds in the `Retry-After` header. content: application/json: schema: $ref: '#/components/schemas/ServiceError' components: schemas: ServiceError: type: object required: - kind - message description: >- Canonical error body returned by every non-2xx response. Extra fields carry error-specific details. properties: kind: type: string enum: - validation - unauthorized - forbidden - not_found - conflict - rate_limited - internal description: Stable, machine-readable error category. message: type: string description: Human-readable explanation of the failure. suggestion: type: string description: >- What to do next when the failure has a known fix; may name the exact operation to call. validValues: type: array items: type: string description: The acceptable values for the failing field, when the set is closed. additionalProperties: true securitySchemes: apiKey: type: http scheme: bearer description: >- Cactal API key. Create one in the dashboard or via `POST /apiKeys`. The plaintext key is shown once at creation. ````