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

# Assign reference number to FBA warehouse inventory

Assigns or updates the seller-side reference number on an FBA warehouse-inventory record. The reference number is yours to use however you want.


## OpenAPI

````yaml post /api/Fba/FbaWarehouseInventory/assignReferenceNumber
openapi: 3.1.0
info:
  title: Return Helper API
  description: API documentation for Return Helper — covering User and Public endpoints.
  version: 1.0.0
servers:
  - url: https://api.returnshelper.com/uat/user
    description: Sandbox — User API
  - url: https://api.returnshelper.com/uat/public
    description: Sandbox — Public API
  - url: https://api.returnhelpercentre.com/v1/user
    description: Production — User API
  - url: https://api.returnhelpercentre.com/v1/public
    description: Production — Public API
  - url: https://api.returnhelperchina.com/user
    description: Production — User API (China)
security:
  - ApiKey: []
    ApiToken: []
paths:
  /api/Fba/FbaWarehouseInventory/assignReferenceNumber:
    post:
      tags:
        - FbaWarehouseInventory
      summary: Assign reference number to FBA warehouse inventory
      operationId: ReturnUserApi_AssignReferenceNumber
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: >-
                #/components/schemas/UserAssignFbaWarehouseInventoryReferenceNumberRequest
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: >-
                  #/components/schemas/GeneralUserAssignFbaWarehouseInventoryReferenceNumberReply
        '401':
          description: >-
            Authentication failed. Returned when the `x-rr-apikey` or
            `x-rr-apitoken` header is missing or invalid. The body uses the
            standard `ApiResponse` envelope with `meta.error.message` describing
            the auth failure.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ApiResponse'
      security:
        - ApiKey: []
          ApiToken: []
      servers:
        - url: https://api.returnshelper.com/uat/user
          description: Sandbox — User API
components:
  schemas:
    UserAssignFbaWarehouseInventoryReferenceNumberRequest:
      type: object
      properties:
        fnsku:
          type: string
          description: FBA SKU
        referenceNumber:
          type: string
          description: Reference number to assign
        warehouseId:
          type: integer
          description: Warehouse where the FBA inventory is located
      required:
        - warehouseId
        - fnsku
        - referenceNumber
    GeneralUserAssignFbaWarehouseInventoryReferenceNumberReply:
      type: object
      properties:
        data:
          $ref: >-
            #/components/schemas/UserAssignFbaWarehouseInventoryReferenceNumberReply
          description: Updated inventory reference number
    ApiResponse:
      type: object
      description: >-
        Universal response envelope. Successful responses include the business
        payload as additional top-level fields alongside `correlationId` and
        `meta`. Failed responses (auth errors, validation errors) only populate
        `correlationId` and `meta`, with `meta.errorCode` and `meta.error`
        describing the failure.
      properties:
        correlationId:
          type:
            - string
            - 'null'
          description: >-
            Unique correlation ID for tracing the request through Return Helper
            systems.
        meta:
          $ref: '#/components/schemas/ApiResponseMeta'
    UserAssignFbaWarehouseInventoryReferenceNumberReply:
      type: object
      properties:
        fbaWarehouseInventoryId:
          type: string
          format: uuid
        warehouseId:
          type: integer
          format: int32
        warehouseDescription:
          type:
            - string
            - 'null'
        fnsku:
          type:
            - string
            - 'null'
        referenceNumber:
          type:
            - string
            - 'null'
        remark:
          type:
            - string
            - 'null'
        quantity:
          type: integer
          format: int32
        availableQuantity:
          type: integer
          format: int32
        modifyBy:
          type:
            - string
            - 'null'
        modifyOn:
          type: string
          format: date-time
    ApiResponseMeta:
      type: object
      description: >-
        Application-level metadata for every API response. Inspect `status` and
        `errorCode` to detect soft-error responses (validation failures arrive
        as HTTP 200 with `meta.status: 400`).
      properties:
        status:
          type: integer
          description: >-
            Application-level status code. For successful operations this
            mirrors the HTTP status (e.g. 200). For validation failures it
            reports the logical status (e.g. 400) even though the wire HTTP
            status is 200.
        data:
          type: object
          additionalProperties:
            type: string
          description: Reserved free-form metadata key/value pairs. Usually empty.
        errorCode:
          type:
            - string
            - 'null'
          description: >-
            Machine-readable error code (e.g. `VALIDATION_FAILED`). Non-null
            only when the operation failed.
        error:
          type: object
          additionalProperties: true
          description: >-
            Field-level or message-level error detail keyed by request property
            name. Empty object on success.
  securitySchemes:
    ApiKey:
      type: apiKey
      in: header
      name: x-rr-apikey
      description: Your API key
    ApiToken:
      type: apiKey
      in: header
      name: x-rr-apitoken
      description: Your API token — keep this private

````