BuiltWith Free Lookup API

openapi: 3.0.3
info:
  title: BuiltWith Change Bulk Processing Free Lookup 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: Free Lookup
  description: Technology count lookups for free tier
paths:
  /api.json:
    get:
      summary: Get technology group counts (JSON)
      description: 'Returns technology category group counts (live and dead) for a domain, organized by tag groups and subcategories. Free tier; rate limited to 1 request/second.

        '
      operationId: getFreeDomainJson
      tags:
      - Free Lookup
      parameters:
      - $ref: '#/components/parameters/KEY'
      - $ref: '#/components/parameters/LOOKUP'
      responses:
        '200':
          description: Technology group counts for the domain
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/FreeResult'
              example:
                domain: builtwith.com
                first: 1262304000
                last: 1748736000
                groups:
                - name: javascript
                  live: 12
                  dead: 45
                  latest: 1748736000
                  oldest: 1262304000
                  categories:
                  - name: social-sdk
                    live: 3
                    dead: 8
                    latest: 1748736000
                    oldest: 1262304000
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
  /api.xml:
    get:
      summary: Get technology group counts (XML)
      operationId: getFreeDomainXml
      tags:
      - Free Lookup
      parameters:
      - $ref: '#/components/parameters/KEY'
      - $ref: '#/components/parameters/LOOKUP'
      responses:
        '200':
          description: Technology group counts in XML
          content:
            application/xml:
              schema:
                type: object
components:
  schemas:
    TechSubcategory:
      type: object
      properties:
        name:
          type: string
          description: Subcategory name
          example: social-sdk
        live:
          type: integer
          description: Active technology count
        dead:
          type: integer
          description: Inactive technology count
        latest:
          type: integer
          format: int64
          description: Most recent detection timestamp
        oldest:
          type: integer
          format: int64
          description: Earliest detection timestamp
    TechGroup:
      type: object
      properties:
        name:
          type: string
          description: Technology tag/category name
          example: javascript
        live:
          type: integer
          description: Count of active technologies
        dead:
          type: integer
          description: Count of inactive technologies
        latest:
          type: integer
          format: int64
          description: Most recent detection timestamp
        oldest:
          type: integer
          format: int64
          description: Earliest detection timestamp
        categories:
          type: array
          items:
            $ref: '#/components/schemas/TechSubcategory'
    ErrorResponse:
      type: object
      properties:
        Errors:
          type: array
          items:
            type: object
            properties:
              Code:
                type: integer
              Message:
                type: string
    FreeResult:
      type: object
      properties:
        domain:
          type: string
          description: The queried domain
        first:
          type: integer
          format: int64
          description: Unix timestamp of first indexing
        last:
          type: integer
          format: int64
          description: Unix timestamp of last indexing
        groups:
          type: array
          items:
            $ref: '#/components/schemas/TechGroup'
  parameters:
    LOOKUP:
      name: LOOKUP
      in: query
      description: Root domain to analyze
      required: true
      schema:
        type: string
        example: builtwith.com
    KEY:
      name: KEY
      in: query
      required: false
      schema:
        type: string
        format: uuid
        example: 00000000-0000-0000-0000-000000000000
  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'
    RateLimited:
      description: Too many requests — free tier limited to 1 request per second
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
  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