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

# Move a package item

> Moves an item, or a partial quantity, from one package to another package on the same order, useful for re-packing before labels are purchased. Both packages must be in `draft` or `packed` status; requires `fulfillment:write` scope.



## OpenAPI

````yaml /openapi.yaml post /packages/{id}/items/{item_id}/move
openapi: 3.1.0
info:
  title: Arcus ERP Public API
  version: 1.0.0
  description: >
    Arcus ERP public REST API. Designed for external integrations and data
    migration.


    **Authentication.** Bearer token (API key) via the `Authorization` header.

    Format: `Authorization: Bearer ark_live_ent_<code>_<random>` (or
    `ark_test_*` for sandbox).

    API keys are issued per-entity in **Settings > Developers > API Keys**.


    **Entity scoping.** The entity is encoded in the API key prefix; routes are
    flat

    (e.g. `/v1/accounts`, `/v1/orders`, `/v1/products`). A small set of platform
    endpoints

    (migration, reconciliation, events, webhook endpoints, API keys) use the

    `/v1/entities/{entity_id}/...` form -- those are noted in their tags.


    **Key capabilities.**
      - Related-resource hydration via `?expand[]=` (see `x-arcus-expand` on each resource).
      - Cursor-based pagination (`starting_after` / `ending_before` / `limit`).
      - Idempotency via the `Idempotency-Key` header.
      - Webhook events for asynchronous notification.
      - Conditional requests / ETag for cache validation.

    **Changelog.** Entries are dated and name every published contract whose
    MEANING moved, not

    only the ones whose field names changed. The narrative version of the same
    entries, written

    for integrators, is published at https://arcuserp.mintlify.app/changelog.


    **2026-09-22 (planned 2026-09-21), REORDER-BUYER-TRUTH: demand changed what
    it MEANS on three

    published contracts, with no field renamed.** An integrator that pins field
    names sees no

    breakage and different numbers, which is why this entry exists.

      - **Demand now counts build consumption.** `demand_avg_per_day` on the public product, kit
        and inventory-balance objects, and `daily_demand` / `demand_basis` / `net_suggested_qty`
        on `GET /v1/purchasing/reorder-report`, are composed from fulfilled sales lines PLUS
        posted `build_consume` inventory draws: each physical decrement of a product counts
        exactly once. The previous rule adopted an internal-consumption basis only when the sales
        blend was exactly zero, so a product both sold AND consumed into work orders planned as
        if the build draws did not exist. Products drawn into work orders move; on one
        production-shaped dataset five did, the largest from 0.05/day to 14.95/day.
      - **`demand_basis` now carries four values, not two:** `sales`, `sales_and_builds`,
        `builds` and `consumption`. A consumer with a two-branch reader (anything that is not
        `consumption` is `sales`) silently hides the two new ones.
      - **`current_demand_units` on `GET /v1/inventory/balances/:id` moved, by a second rule.**
        It counts committed-but-unshipped CUSTOMER demand, and it now counts a kit component's
        own line rather than its parent kit line, and excludes non-sales documents. On one
        production dataset 269 of 1,043 balance rows changed, 227 of them downward; the largest
        single move was 1,941 to 25, on a product whose open PURCHASE order line had been
        reported as customer demand. Re-baseline anything that alerts or reorders off this field.
      - `run_rate_30/90/180/365` and `blended_daily` on the same balance object move for the
        first reason above.
      - **Added, not changed:** `GET /v1/purchasing/reorder-report` accepts `demand_window` and
        returns the unit, cover-through and reorder-point-provenance fields documented on that
        operation; `order_multiple` is accepted and returned on the product-vendor doors.
      - **Volume note.** The `inventory.low_stock`, `inventory.out_of_stock` and
        `inventory.back_in_stock` webhook events are population-gated on
        `on_hand <= reorder_point`, and reorder points move with the demand above, so
        subscribers should expect a one-time step change in event volume around the release.
servers:
  - url: https://api.arcuserp.com/v1
    description: Arcus ERP API (accepts both live `ark_live_*` and test `ark_test_*` keys)
  - url: https://dev-api.arcuserp.com/v1
    description: >-
      Dev sandbox API (test-only data, accepts `ark_test_*` keys against dev
      RDS)
security: []
paths:
  /packages/{id}/items/{item_id}/move:
    parameters:
      - name: id
        in: path
        required: true
        schema:
          type: string
          format: uuid
      - name: item_id
        in: path
        required: true
        schema:
          type: string
          format: uuid
    post:
      tags:
        - Fulfillment
      summary: Move a package item
      description: >-
        Moves an item, or a partial quantity, from one package to another
        package on the same order, useful for re-packing before labels are
        purchased. Both packages must be in `draft` or `packed` status; requires
        `fulfillment:write` scope.
      operationId: movePackageItem
      parameters:
        - $ref: '#/components/parameters/IdempotencyKey'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - target_package_id
              properties:
                target_package_id:
                  type: string
                  format: uuid
                quantity:
                  type: integer
                  minimum: 1
      responses:
        '200':
          description: Item moved; returns updated source and target package items
          content:
            application/json:
              schema:
                type: object
                properties:
                  source:
                    $ref: '#/components/schemas/PackageItem'
                  target:
                    $ref: '#/components/schemas/PackageItem'
        '400':
          $ref: '#/components/responses/Error'
        '401':
          $ref: '#/components/responses/Error'
        '403':
          $ref: '#/components/responses/Error'
        '404':
          $ref: '#/components/responses/Error'
      security:
        - ApiKeyAuth: []
components:
  parameters:
    IdempotencyKey:
      name: Idempotency-Key
      in: header
      required: false
      description: |
        Client-generated unique key for idempotent POST/PATCH/DELETE operations.
        Alias for the Idempotency parameter. Max 255 chars. On retry with the
        same key, the original response is returned without re-executing the
        operation. Keys expire after 24 hours.
      schema:
        type: string
        maxLength: 255
  schemas:
    PackageItem:
      type: object
      description: >-
        A line item placed inside a package (one order_item can be split across
        packages).
      properties:
        id:
          type: string
          format: uuid
        package_id:
          type: string
          format: uuid
        order_item_id:
          type: string
          format: uuid
        product_id:
          type: string
          format: uuid
          nullable: true
        quantity:
          type: integer
          description: Qty of this order_item packed into this package.
        sku:
          type: string
          nullable: true
        title:
          type: string
          nullable: true
        serial_numbers:
          type: array
          items:
            type: string
          nullable: true
        created_at:
          type: string
          format: date-time
          readOnly: true
    ErrorEnvelope:
      type: object
      description: |
        Canonical error response envelope. All API errors use this shape.
      required:
        - error
        - code
      properties:
        error:
          type: string
          description: Machine-readable error key
          example: not_found
        code:
          type: string
          description: Machine-readable error code (often same as error)
          example: not_found
        type:
          type: string
          enum:
            - validation_error
            - permission_error
            - not_found
            - conflict
            - rate_limit
            - internal
            - expand_error
            - not_implemented
          example: not_found
        hint:
          type: string
          description: Human-readable one-sentence explanation (English)
          example: >-
            The requested order does not exist or does not belong to this
            entity.
        param:
          type: string
          description: The parameter that caused the error, if applicable
          example: expand[0]
        required:
          type: string
          description: The scope required (only on insufficient_scope errors)
          example: accounts:read
        request_id:
          type: string
          description: >-
            Unique request ID for support tracing (maps to CloudWatch log
            stream)
          example: req_abc123
  responses:
    Error:
      description: Error response (400/401/403/404/409/422/429/500)
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorEnvelope'
  securitySchemes:
    ApiKeyAuth:
      type: http
      scheme: bearer
      description: |
        API key issued per entity via Settings > Developers > API Keys.
        Each key carries scopes (e.g. orders:read, products:write).
        Bearer token format: Authorization: Bearer ark_live_ent_<code>_<random>
        Test keys use ark_test_ent_<code>_<random>. Both are issued per entity
        via Settings > Developers > API Keys.

````

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