openapi: 3.2.0
info:
  title: Cisco Umbrella Investigate Popularity List-Top Million Domains API
  description: 'The Umbrella Investigate API provides a complete view of domains in relation to IP and autonomous system number (ASN) information.

    You can get the following domain information:


    * Domain status, risk score, and geolocation

    * Number of domain searches

    * Co-occurring domains

    * Subdomains of a domain

    * Tagged timeline of a domain, IP, or URL

    * Security reputation of a domain

    * Top accessed domains

    * WHOIS information for the domain

    * Threat intelligence data for domains, IPs, and URLs

    * Threat intelligence samples by file hash'
  version: 2.0.0
  contact:
    name: Cloud Security Developer Community
  x-provenance:
    method: harvested
    authored_by: Cisco Umbrella
    harvested_by: API Evangelist
    harvested_on: '2026-08-19'
    first_party: true
    provider_published: true
    source_host: pubhub.devnetcloud.com
    note: 26 first-party OpenAPI 3.0 documents (256 operations) listed by Cisco's own docs-nav config and fetched anonymously. Byte-identity reconfirmed 2026-08-19 by SHA-256 against the live source.
  x-evidence:
  - type: source
    url: https://pubhub.devnetcloud.com/media/cloud-security-apis-in-eft/docs/umbrella-config.json
  - type: source
    url: https://developer.cisco.com/docs/cloud-security/
servers:
- url: https://api.umbrella.com/{basePath}
  variables:
    basePath:
      default: investigate/v2
security:
- oauthFlow: []
tags:
- name: Popularity List-Top Million Domains
paths:
  /topmillion:
    get:
      summary: Get Top Most Seen Domains
      operationId: getTopmillion
      tags:
      - Popularity List-Top Million Domains
      description: 'List the most seen domains in Umbrella. You can download the data in a zip file,

        or use the Investigate API to stream the data into a SIEM.

        The popularity list contains our most queried domains based on passive DNS usage across

        our Umbrella global network of more than 180 billion requests per day with many tens of millions

        of unique active users, in more than 165 countries.

        The metric does not only consist of browser-based http requests from users but also takes

        in to account the number of unique client IPs invoking this domain relative to the sum of all requests

        to all domains.

        Our popularity ranking reflects the domain''s relative internet activity agnostic

        to the invocation protocols and applications where as site ranking models (such as Alexa) focus

        on the web activity over port 80 (primarily from browsers).

        In addition, the Umbrella popularity algorithm also applies data normalization techniques

        to smooth potential biases that may occur due to sampling of DNS usage data.

        '
      parameters:
      - name: limit
        in: query
        required: false
        description: 'The maximum number of domains to return in the list.

          If you do not set a limit, Investigate returns up to one million results.'
        schema:
          type: integer
        example: 1000
      security:
      - oauthFlow:
        - investigate.investigate:read
      responses:
        '200':
          description: OK
          headers:
            Content-Type:
              $ref: '#/components/headers/Content-Type'
            Date:
              $ref: '#/components/headers/Date'
          content:
            application/json:
              schema:
                type: array
                description: The list of the most popular domains identified by the Umbrella DNS resolvers.
                items:
                  type: string
                  description: A popular domain name identified by the Umbrella DNS resolvers.
                  example: g.doubleclick.net
              example:
              - google.com
              - netflix.com
              - api-global.netflix.com
              - microsoft.com
              - www.google.com
              - facebook.com
              - doubleclick.net
              - g.doubleclick.net
              - googleads.g.doubleclick.net
              - hola.org
        '400':
          $ref: '#/components/responses/400Error'
        '401':
          $ref: '#/components/responses/401Error'
        '403':
          $ref: '#/components/responses/403Error'
        '404':
          $ref: '#/components/responses/404Error'
        '500':
          $ref: '#/components/responses/500Error'
components:
  headers:
    Content-Type:
      schema:
        type: string
      description: The MIME content type of the response body.
      example: application/json
    Date:
      schema:
        type: string
        pattern: ^[0-90-90-90-9-0-90-9-0-90-9T0-90-9:0-90-9:0-90-9Z]+$
      description: The timestamp of the response.
      example: '2023-03-14T18:34:25Z'
  responses:
    403Error:
      description: Forbidden
      headers:
        Content-Type:
          $ref: '#/components/headers/Content-Type'
        Date:
          $ref: '#/components/headers/Date'
      content:
        application/json:
          schema:
            type: object
            properties:
              message:
                type: string
    500Error:
      description: Internal Server Error
      headers:
        Content-Type:
          $ref: '#/components/headers/Content-Type'
        Date:
          $ref: '#/components/headers/Date'
      content:
        application/json:
          schema:
            type: object
            properties:
              message:
                type: string
    401Error:
      description: Unauthorized
      headers:
        Content-Type:
          $ref: '#/components/headers/Content-Type'
        Date:
          $ref: '#/components/headers/Date'
      content:
        application/json:
          schema:
            type: object
            properties:
              message:
                type: string
    404Error:
      description: Not Found
      headers:
        Content-Type:
          $ref: '#/components/headers/Content-Type'
        Date:
          $ref: '#/components/headers/Date'
      content:
        application/json:
          schema:
            type: object
            properties:
              message:
                type: string
    400Error:
      description: Bad Request
      headers:
        Content-Type:
          $ref: '#/components/headers/Content-Type'
        Date:
          $ref: '#/components/headers/Date'
      content:
        application/json:
          schema:
            type: object
            properties:
              message:
                type: string
  securitySchemes:
    oauthFlow:
      type: oauth2
      description: The client credential flow.
      flows:
        clientCredentials:
          scopes:
            investigate.investigate:read: Investigate read access
            investigate.bulk:read: Investigate bulk read access
          tokenUrl: https://api.umbrella.com/auth/v2/token
x-provenance:
  method: harvested
  first_party: true
  harvested: '2026-08-19'
  source: https://pubhub.devnetcloud.com/media/cloud-security-apis-in-eft/docs/reference/investigate/investigate.yaml
  publisher: Cisco Systems, Inc. (Cisco DevNet Cloud Security docs)
x-evidence:
  fetched: '2026-08-19'
  url: https://pubhub.devnetcloud.com/media/cloud-security-apis-in-eft/docs/reference/investigate/investigate.yaml
  http_status: 200
  docs: https://developer.cisco.com/docs/cloud-security/