> ## Documentation Index
> Fetch the complete documentation index at: https://apidocs.specurate.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Add Alternative



## OpenAPI

````yaml /openapi.json post /v1/workspaces/{workspaceId}/projects/{projectId}/item-slots/{id}/alternatives
openapi: 3.1.0
info:
  title: Specurate API
  description: ''
  version: 1.0.0
  contact: {}
servers:
  - url: https://app.specurate.com/api
    description: API Server
security: []
tags: []
paths:
  /v1/workspaces/{workspaceId}/projects/{projectId}/item-slots/{id}/alternatives:
    post:
      tags:
        - Project Item Slots
      summary: Add Alternative
      operationId: ProjectItemSlotsController_addAlternative_v1
      parameters:
        - name: workspaceId
          required: true
          in: path
          schema:
            type: string
        - name: projectId
          required: true
          in: path
          schema:
            type: string
        - name: id
          required: true
          in: path
          schema:
            type: string
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AddAlternativeDto'
      responses:
        '409':
          description: ''
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponseDto'
components:
  schemas:
    AddAlternativeDto:
      type: object
      properties:
        mode:
          enum:
            - pick
            - create
          type: string
          description: pick = link to existing catalog entry; create = new family + item
        catalogFamilyId:
          type: string
          description: (mode=pick) BigInt ID of the catalog family to link
        catalogItemId:
          type: string
          description: (mode=pick) BigInt ID of the catalog item to link
        sourceSelection:
          oneOf:
            - $ref: '#/components/schemas/ExactCatalogSourceSelectionDto'
            - $ref: '#/components/schemas/EstimateCatalogSourceSelectionDto'
        name:
          type: string
          maxLength: 200
          description: (mode=create) Name for the new catalog family / project item
        categoryId:
          type: string
          description: (mode=create) BigInt ID of the category for the new family
      required:
        - mode
    ErrorResponseDto:
      type: object
      properties:
        statusCode:
          type: number
          example: 409
        message:
          type: string
          example: Conflict
        code:
          type: string
          example: VARIANT_COMBO_TAKEN
          description: >-
            UPPER_SNAKE_CASE domain error code. Present on validation /
            business-rule errors; absent on generic HTTP errors.
        entity:
          type: string
          description: >-
            Entity type that caused the conflict (e.g. "ProjectItem"). Present
            when the error is entity-specific.
      required:
        - statusCode
        - message
    ExactCatalogSourceSelectionDto:
      type: object
      properties:
        mode:
          enum:
            - catalog_item_source
          type: string
        catalogItemSourceId:
          type: string
      required:
        - mode
        - catalogItemSourceId
    EstimateCatalogSourceSelectionDto:
      type: object
      properties:
        mode:
          enum:
            - estimate
          type: string
      required:
        - mode

````