openapi: 3.0.1
info:
  title: US Senate Lobbying Disclosure Act (LDA) Clients Registrants API
  description: The Senate Lobbying Disclosure Act (LDA) REST API provides public access to lobbying filings, registrations, quarterly activity reports (LD-2), and semi-annual contribution reports (LD-203). An optional API key increases the rate limit from 15 to 120 requests per minute.
  version: '1.0'
  contact:
    name: Senate Office of Public Records
    email: lobby@sec.senate.gov
    url: https://lda.senate.gov/api/
servers:
- url: https://lda.senate.gov/api/v1
security:
- ApiKeyAuth: []
- {}
tags:
- name: Registrants
  description: Lobbying firm and self-employed lobbyist registrations
paths:
  /registrants/:
    get:
      tags:
      - Registrants
      operationId: listRegistrants
      summary: List Lobbying Registrants
      description: Returns a paginated list of lobbying registrants (firms and individuals).
      parameters:
      - name: name
        in: query
        description: Filter by registrant name (partial match)
        schema:
          type: string
      - name: page
        in: query
        schema:
          type: integer
          default: 1
      - name: format
        in: query
        schema:
          type: string
          enum:
          - json
          default: json
      responses:
        '200':
          description: Paginated list of registrants
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/RegistrantListResponse'
  /registrants/{id}/:
    get:
      tags:
      - Registrants
      operationId: getRegistrant
      summary: Get Registrant by ID
      description: Retrieve a specific lobbying registrant by ID.
      parameters:
      - name: id
        in: path
        required: true
        description: Registrant ID
        schema:
          type: integer
      - name: format
        in: query
        schema:
          type: string
          enum:
          - json
          default: json
      responses:
        '200':
          description: Registrant details
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Registrant'
        '404':
          description: Not found
components:
  schemas:
    Registrant:
      type: object
      description: A lobbying firm or self-employed lobbyist registration
      properties:
        id:
          type: integer
        url:
          type: string
          format: uri
        house_registrant_id:
          type: integer
        name:
          type: string
          description: Name of the lobbying firm or individual
        description:
          type: string
          nullable: true
        address_1:
          type: string
          nullable: true
        city:
          type: string
          nullable: true
        state:
          type: string
          nullable: true
        zip:
          type: string
          nullable: true
        country:
          type: string
        contact_name:
          type: string
        contact_telephone:
          type: string
        dt_updated:
          type: string
          format: date-time
    RegistrantListResponse:
      type: object
      properties:
        count:
          type: integer
        next:
          type: string
          format: uri
          nullable: true
        previous:
          type: string
          format: uri
          nullable: true
        results:
          type: array
          items:
            $ref: '#/components/schemas/Registrant'
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: Authorization
      description: 'Token-based auth. Format: ''Token YOUR_API_KEY'''