openapi: 3.0.3
info:
  title: Unum HR Connect Authentication Billing API
  description: The Unum HR Connect API provides a secure, real-time connection between Unum benefits and major HR platforms including Workday, ADP, and UKG. It automates eligibility checks, evidence of insurability (EOI) processing, premium billing calculations, leave and absence management, and enrollment data synchronization for employers and HR technology partners.
  version: '1.0'
  contact:
    name: Unum Developer Support
    url: https://developer.unum.com/s/
  termsOfService: https://www.unum.com/legal
servers:
- url: https://api.unum.com/v1
  description: Unum Production API
security:
- OAuth2:
  - eligibility:read
  - enrollment:read
  - leave:read
  - eoi:read
  - billing:read
tags:
- name: Billing
  description: Premium billing and payment management
paths:
  /billing/invoices:
    get:
      operationId: listBillingInvoices
      summary: List Billing Invoices
      description: Retrieve premium billing invoices for an employer group.
      tags:
      - Billing
      parameters:
      - name: groupId
        in: query
        required: true
        schema:
          type: string
        description: Employer group identifier
      - name: startDate
        in: query
        schema:
          type: string
          format: date
        description: Filter invoices from this date
      - name: endDate
        in: query
        schema:
          type: string
          format: date
        description: Filter invoices up to this date
      - name: page
        in: query
        schema:
          type: integer
          default: 1
      - name: limit
        in: query
        schema:
          type: integer
          default: 100
      responses:
        '200':
          description: List of billing invoices
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/BillingInvoiceList'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /billing/invoices/{invoiceId}:
    get:
      operationId: getBillingInvoice
      summary: Get Billing Invoice
      description: Retrieve details of a specific premium billing invoice.
      tags:
      - Billing
      parameters:
      - name: invoiceId
        in: path
        required: true
        schema:
          type: string
        description: Invoice identifier
      responses:
        '200':
          description: Billing invoice details
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/BillingInvoice'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
components:
  responses:
    NotFound:
      description: Resource not found
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    Unauthorized:
      description: Authentication credentials missing or invalid
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  schemas:
    BillingLineItem:
      type: object
      properties:
        lineItemId:
          type: string
        memberId:
          type: string
        productType:
          type: string
        planCode:
          type: string
        premium:
          type: number
          format: double
        coverageLevel:
          type: string
    Error:
      type: object
      properties:
        code:
          type: string
          description: Error code
        message:
          type: string
          description: Human-readable error message
        details:
          type: array
          items:
            type: object
            properties:
              field:
                type: string
              message:
                type: string
    BillingInvoice:
      type: object
      properties:
        invoiceId:
          type: string
        groupId:
          type: string
        billingPeriodStart:
          type: string
          format: date
        billingPeriodEnd:
          type: string
          format: date
        totalPremium:
          type: number
          format: double
        currency:
          type: string
          example: USD
        status:
          type: string
          enum:
          - pending
          - paid
          - overdue
          - void
        dueDate:
          type: string
          format: date
        lineItems:
          type: array
          items:
            $ref: '#/components/schemas/BillingLineItem'
        createdAt:
          type: string
          format: date-time
    BillingInvoiceList:
      type: object
      properties:
        data:
          type: array
          items:
            $ref: '#/components/schemas/BillingInvoice'
        total:
          type: integer
        page:
          type: integer
        limit:
          type: integer
  securitySchemes:
    OAuth2:
      type: oauth2
      flows:
        clientCredentials:
          tokenUrl: https://api.unum.com/v1/oauth/token
          scopes:
            eligibility:read: Read member eligibility
            eligibility:write: Write member eligibility
            enrollment:read: Read enrollment elections
            enrollment:write: Write enrollment elections
            leave:read: Read leave requests
            leave:write: Write leave requests
            eoi:read: Read EOI submissions
            eoi:write: Write EOI submissions
            billing:read: Read billing invoices