openapi: 3.0.3
info:
  title: Unum HR Connect Authentication 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: Authentication
  description: OAuth 2.0 token management
paths:
  /oauth/token:
    post:
      operationId: getAccessToken
      summary: Get Access Token
      description: Obtain an OAuth 2.0 access token using client credentials for API authorization.
      tags:
      - Authentication
      requestBody:
        required: true
        content:
          application/x-www-form-urlencoded:
            schema:
              type: object
              required:
              - grant_type
              - client_id
              - client_secret
              properties:
                grant_type:
                  type: string
                  enum:
                  - client_credentials
                  description: OAuth grant type
                client_id:
                  type: string
                  description: Client application identifier
                client_secret:
                  type: string
                  description: Client application secret
      responses:
        '200':
          description: Access token response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AccessToken'
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  responses:
    Unauthorized:
      description: Authentication credentials missing or invalid
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  schemas:
    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
    AccessToken:
      type: object
      properties:
        access_token:
          type: string
          description: Bearer access token
        token_type:
          type: string
          example: Bearer
        expires_in:
          type: integer
          description: Token expiration in seconds
          example: 3600
        scope:
          type: string
          description: Granted OAuth scopes
  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