openapi: 3.0.3
info:
  title: BuiltWith Change Bulk Processing Technology Changes API
  description: 'Track technology additions and removals on websites with business context. Returns AI-generated summaries explaining the business significance of technology changes. Credits are only consumed when changes are found.

    '
  version: change1
  contact:
    name: BuiltWith Support
    url: https://builtwith.com/contact
  termsOfService: https://builtwith.com/terms
  license:
    name: Commercial
    url: https://builtwith.com/plans
servers:
- url: https://api.builtwith.com/change1
  description: BuiltWith Change API v1
security:
- apiKeyQuery: []
- apiKeyHeader: []
tags:
- name: Technology Changes
  description: Track technology additions and removals on websites
paths:
  /api.json:
    get:
      summary: Get technology changes for domain(s)
      description: 'Returns technology additions and removals for one or more domains, with optional SINCE parameter to scope the detection window. AI-generated summaries explain the business significance of each change. 1 API credit per domain with changes; no charge for domains with none.

        '
      operationId: getDomainChanges
      tags:
      - Technology Changes
      parameters:
      - $ref: '#/components/parameters/KEY'
      - $ref: '#/components/parameters/LOOKUP'
      - $ref: '#/components/parameters/SINCE'
      responses:
        '200':
          description: Technology changes for the requested domain(s)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ChangesResponse'
              example:
                Results:
                - Lookup: example.com
                  Changes:
                    since_utc: '2026-05-01T00:00:00Z'
                    last_checked_utc: '2026-06-10T12:00:00Z'
                    summary: Example.com adopted HubSpot CRM and removed Salesforce.
                    events:
                    - type: technology_added
                      technology: HubSpot CRM
                      category:
                      - CRM
                      - Marketing Automation
                      tag: analytics
                      first_seen_utc: '2026-05-15T08:00:00Z'
                      importance: high
                      why_this_matters: Switching to HubSpot typically signals a focus on inbound marketing.
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  schemas:
    ChangesResponse:
      type: object
      properties:
        Results:
          type: array
          items:
            $ref: '#/components/schemas/DomainChanges'
    DomainChanges:
      type: object
      properties:
        Lookup:
          type: string
          description: The queried domain
        Changes:
          $ref: '#/components/schemas/ChangeSet'
    ChangeSet:
      type: object
      properties:
        since_utc:
          type: string
          format: date-time
          description: Detection window start
        last_checked_utc:
          type: string
          format: date-time
          description: Most recent scan timestamp
        summary:
          type: string
          description: AI-generated overview of additions and removals
        events:
          type: array
          items:
            $ref: '#/components/schemas/ChangeEvent'
    ChangeEvent:
      type: object
      properties:
        type:
          type: string
          enum:
          - technology_added
          - technology_removed
          description: Whether the technology was added or removed
        technology:
          type: string
          description: Name of the technology
        category:
          type: array
          items:
            type: string
          description: BuiltWith technology categories
        tag:
          type: string
          description: Technology tag classification
        first_seen_utc:
          type: string
          format: date-time
          description: Timestamp when the addition was first detected
        last_seen_utc:
          type: string
          format: date-time
          description: Timestamp when the removal was last detected
        importance:
          type: string
          enum:
          - low
          - medium
          - high
          description: Priority level of the change
        why_this_matters:
          type: string
          description: AI-generated explanation of the business significance
    ErrorResponse:
      type: object
      properties:
        Errors:
          type: array
          items:
            type: object
            properties:
              Code:
                type: integer
              Message:
                type: string
  responses:
    Unauthorized:
      description: Unauthorized — invalid or missing API key
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    BadRequest:
      description: Bad request — invalid parameters
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
  parameters:
    SINCE:
      name: SINCE
      in: query
      description: Time window for change detection; natural language or ISO 8601 date
      required: false
      schema:
        type: string
        example: last month
    LOOKUP:
      name: LOOKUP
      in: query
      description: Single domain or comma-separated list of domains
      required: true
      schema:
        type: string
        example: hotelscombined.com
    KEY:
      name: KEY
      in: query
      required: false
      schema:
        type: string
        format: uuid
        example: 00000000-0000-0000-0000-000000000000
  securitySchemes:
    apiKeyQuery:
      type: apiKey
      in: query
      name: KEY
    apiKeyHeader:
      type: apiKey
      in: header
      name: Authorization
      description: 'Format: ''Authorization: API {key}'''
externalDocs:
  description: BuiltWith Change API Documentation
  url: https://api.builtwith.com/change-api