> ## 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. # Preview an order's allocation plan > Returns the proposed per-line multi-warehouse sourcing plan for an order without reserving any stock, so it can be reviewed before committing it with the allocate operation. Read-only; it writes no inventory and posts no journal entry. ## OpenAPI ````yaml /openapi.yaml post /orders/{id}/allocation-plan 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__` (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: /orders/{id}/allocation-plan: parameters: - name: id in: path required: true schema: type: string format: uuid post: tags: - Orders summary: Preview an order's allocation plan description: >- Returns the proposed per-line multi-warehouse sourcing plan for an order without reserving any stock, so it can be reviewed before committing it with the allocate operation. Read-only; it writes no inventory and posts no journal entry. operationId: getOrderAllocationPlan responses: '200': description: The proposed allocation plan. content: application/json: schema: type: object properties: data: type: object properties: order_id: type: string format: uuid order_number: type: string preferred_location_id: type: string format: uuid order_allocation_strategy: type: string enum: - allocate_now - allocate_at_pack any_multi_location: type: boolean any_shortfall: type: boolean lines: type: array items: type: object properties: order_item_id: type: string format: uuid product_id: type: string format: uuid product_title: type: string nullable: true sku: type: string nullable: true qty_needed: type: integer qty_plannable: type: integer shortfall: type: integer fully_sourceable: type: boolean multi_location: type: boolean allocation_strategy: type: string enum: - allocate_now - allocate_at_pack plan: type: array items: type: object properties: location_id: type: string format: uuid location_name: type: string qty: type: integer available: type: integer '404': description: Order not found. '422': description: >- No resolvable location (order has no location and entity has no default). security: - ApiKeyAuth: [] components: 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__ Test keys use ark_test_ent__. Both are issued per entity via Settings > Developers > API Keys. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.