> ## Documentation Index
> Fetch the complete documentation index at: https://docs.projectdiscovery.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Get Associated Domains

> Discover domains related to a given domain through acquisition history, certificate transparency logs, and WHOIS records. Returns associated domains with evidence of their relationship.

<Note>
  This endpoint discovers domains related to a given domain through multiple intelligence sources: acquisition history, certificate transparency logs, and WHOIS records.

  **Default Behavior:** When called without the `domain` parameter, returns associated domains for all your verified domains. Optionally provide a `domain` parameter to query associated domains for a specific domain.

  **Result Limits:** Results are limited to 10 associated domains per query. Enterprise plans include full results with pagination support. Contact [sales](https://projectdiscovery.io/request-demo) to access complete results.
</Note>

<Tip>
  Retrieve your API key from [Settings → API Key](https://cloud.projectdiscovery.io/settings/api-key) in the ProjectDiscovery Cloud Platform.
</Tip>

## Discovery Sources

The Associated Domains API correlates data from three primary sources:

| Source                | Description                                                                      |
| --------------------- | -------------------------------------------------------------------------------- |
| `acquisition_history` | Corporate subsidiaries and acquired companies from business intelligence sources |
| `certificate_history` | SSL/TLS certificate transparency logs revealing shared infrastructure            |
| `whois_history`       | Domain registration records identifying common ownership                         |

## Example Requests

### Get all associated domains

```bash theme={null}
curl -X GET "https://api.projectdiscovery.io/v1/domain/associated?domain=meta.com" \
  -H "X-Api-Key: YOUR_API_KEY"
```

### Filter by specific source

```bash theme={null}
# Only certificate-based associations
curl -X GET "https://api.projectdiscovery.io/v1/domain/associated?domain=meta.com&source=certificate_history" \
  -H "X-Api-Key: YOUR_API_KEY"

# Multiple sources
curl -X GET "https://api.projectdiscovery.io/v1/domain/associated?domain=meta.com&source=acquisition_history,whois_history" \
  -H "X-Api-Key: YOUR_API_KEY"
```

### Filter by liveness

```bash theme={null}
# Only active/reachable domains
curl -X GET "https://api.projectdiscovery.io/v1/domain/associated?domain=meta.com&active=true" \
  -H "X-Api-Key: YOUR_API_KEY"
```

### Paginated results

```bash theme={null}
curl -X GET "https://api.projectdiscovery.io/v1/domain/associated?domain=meta.com&limit=50&page=1&sort=subdomain_count" \
  -H "X-Api-Key: YOUR_API_KEY"
```

### Raw output (plain text)

```bash theme={null}
# Get just domain names, one per line (useful for piping to other tools)
curl -X GET "https://api.projectdiscovery.io/v1/domain/associated?domain=meta.com&raw=true" \
  -H "X-Api-Key: YOUR_API_KEY"
```

## Related Resources

* [Associated Domains Discovery Guide](/cloud/assets/associated-domains) - Comprehensive feature documentation
* [Asset Discovery Overview](/cloud/assets/overview) - Platform asset management capabilities


## OpenAPI

````yaml get /v1/domain/associated
openapi: 3.1.0
info:
  title: PDCP API
  version: '1.0'
  summary: ProjectDiscovery Cloud Platform
  description: >-
    For more details, checkout
    https://docs.projectdiscovery.io/api-reference/editor/scan
servers:
  - url: https://api.projectdiscovery.io
    description: Production
  - url: https://api.dev.projectdiscovery.io
    description: Development
  - url: http://localhost:8085
    description: Localhost
security:
  - X-API-Key: []
paths:
  /v1/domain/associated:
    parameters: []
    get:
      tags:
        - chaos
      summary: Get Associated Domains
      description: >-
        Discover domains related to a given domain through acquisition history,
        certificate transparency logs, and WHOIS records. Returns associated
        domains with evidence of their relationship.
      operationId: associated-domains
      parameters:
        - schema:
            type: string
          in: query
          name: domain
          description: >-
            Domain name to fetch associated domains. If omitted, returns
            associated domains for all your verified domains.
        - schema:
            type: string
          in: query
          name: source
          description: >-
            Comma-separated source filter (acquisition_history,
            certificate_history, whois_history)
        - schema:
            type: boolean
          in: query
          name: active
          description: Filter by liveness (true=alive, false=unreachable)
        - schema:
            type: string
            enum:
              - active
              - domain
              - source
              - subdomain_count
              - update_date
          in: query
          name: sort
          description: Sort results
        - schema:
            type: integer
          in: query
          name: limit
          description: Maximum results per page (pagination). If omitted, returns all.
        - schema:
            type: integer
          in: query
          name: page
          description: Page number (pagination, starts at 1)
        - schema:
            type: boolean
          in: query
          name: raw
          description: If true, returns plain text list (one domain per line)
        - schema:
            type: string
          in: header
          name: X-Team-Id
      responses:
        '200':
          $ref: '#/components/responses/AssociatedDomainsResults'
        '400':
          $ref: '#/components/responses/ErrorResponse'
        '401':
          $ref: '#/components/responses/ErrorResponse'
        '500':
          $ref: '#/components/responses/ErrorResponse'
        default:
          $ref: '#/components/responses/ErrorResponse'
components:
  responses:
    AssociatedDomainsResults:
      description: Associated domains response
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/AssociatedDomainsResultSet'
        text/plain:
          schema:
            type: string
            description: Plain text list of domains when raw=true
    ErrorResponse:
      description: Example response
      content:
        application/json:
          schema:
            type: object
            required:
              - message
            properties:
              message:
                type: string
              kind:
                type: string
              code:
                type: string
              error:
                type: string
              error_id:
                type: string
              param:
                type: string
              status:
                type: integer
  schemas:
    AssociatedDomainsResultSet:
      title: AssociatedDomainsResultSet
      type: object
      required:
        - domain
        - results
        - sources
      properties:
        domain:
          description: Queried domain
          type: string
        results:
          description: List of associated domains
          type: array
          items:
            $ref: '#/components/schemas/AssociatedDomainResult'
        sources:
          description: List of sources used in the query
          type: array
          items:
            type: string
        sources_count:
          description: Count of results per source
          type: object
          additionalProperties:
            type: integer
        unique_count:
          description: Unique associated domains count
          type: integer
        limit:
          description: Maximum results per page when paginated
          type: integer
        page:
          description: Current page when paginated
          type: integer
        total_count:
          description: Total associated domains when paginated
          type: integer
        total_pages:
          description: Total pages when paginated
          type: integer
    AssociatedDomainResult:
      title: AssociatedDomainResult
      type: object
      required:
        - domain
        - sources
      properties:
        domain:
          description: Associated domain name
          type: string
        evidence:
          $ref: '#/components/schemas/AssociatedDomainEvidence'
        sources:
          description: Sources that reported the association
          type: array
          items:
            type: string
    AssociatedDomainEvidence:
      title: AssociatedDomainEvidence
      type: object
      properties:
        acquired_company:
          description: Acquired company name
          type: string
        acquired_date:
          description: Acquisition date
          type: string
        acquirer_name:
          description: Acquirer organization name
          type: string
        active:
          description: Whether the domain is reachable
          type: boolean
        as_name:
          description: Autonomous system name
          type: string
        as_number:
          description: Autonomous system number
          type: integer
        cert_common_name:
          description: Certificate common name
          type: string
        cert_expiry_date:
          description: Certificate expiry date
          type: string
        cert_issued_date:
          description: Certificate issued date
          type: string
        cert_issuer:
          description: Certificate issuer
          type: string
        cert_org_name:
          description: Certificate organization name
          type: string
        cert_serial:
          description: Certificate serial number
          type: string
        crunchbase_url:
          description: Crunchbase URL
          type: string
        expiry_date:
          description: Domain expiry date
          type: string
        location:
          description: Geographic location
          type: string
        orgname:
          description: WHOIS organization name
          type: string
        probe:
          description: Probe information
          type: string
        registrant_org:
          description: Registrant organization
          type: string
        registrar:
          description: Registrar name
          type: string
        registration_date:
          description: Domain registration date
          type: string
        search_identifier:
          description: Search identifier
          type: string
        status_code:
          description: HTTP status code
          type: integer
        subdomain_count:
          description: Number of discovered subdomains
          type: integer
        title:
          description: HTTP title
          type: string
        update_date:
          description: Last update date
          type: string
        whois_server:
          description: WHOIS server
          type: string
  securitySchemes:
    X-API-Key:
      name: X-API-Key
      type: apiKey
      in: header

````