> ## 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. # Advance a migration counter > Moves a document-numbering counter forward to match the highest number already used in the source system, so newly created documents don't collide with migrated ones. The counter can only move forward; requires `migration:admin` and `migration:write` scopes. ## OpenAPI ````yaml /openapi.yaml post /entities/{entity_id}/migration/counters/advance 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: /entities/{entity_id}/migration/counters/advance: post: tags: - Migration summary: Advance a migration counter description: >- Moves a document-numbering counter forward to match the highest number already used in the source system, so newly created documents don't collide with migrated ones. The counter can only move forward; requires `migration:admin` and `migration:write` scopes. operationId: postMigrationCounterAdvance parameters: - name: entity_id in: path required: true schema: type: string format: uuid - name: Idempotency-Key in: header required: false schema: type: string description: > Optional idempotency key. If supplied, retrying the same call within 24 hours returns the previous result. requestBody: required: true content: application/json: schema: oneOf: - $ref: '#/components/schemas/MigrationCounterAdvanceSingle' - $ref: '#/components/schemas/MigrationCounterAdvanceBatch' examples: single: summary: Single counter advance value: counter_type: invoice advance_to: 342665 batch: summary: Batch counter advance (all counters at cutover) value: counters: - counter_type: invoice advance_to: 342665 - counter_type: order advance_to: 250000 - counter_type: vendor_bill advance_to: 24044 responses: '200': description: Counter advance result content: application/json: schema: $ref: '#/components/schemas/MigrationCounterAdvanceResult' '400': $ref: '#/components/responses/Error' '401': $ref: '#/components/responses/Error' '403': $ref: '#/components/responses/Error' security: - ApiKeyAuth: [] components: schemas: MigrationCounterAdvanceSingle: type: object required: - counter_type - advance_to description: Single-counter advance payload. properties: counter_type: type: string description: > One of the counter_type enum values: order, invoice, quote, po, rma, journal, account, vendor_bill, ap_payment, check, transfer, vendor_return, refund, inventory_txn, work_order, fixed_asset, lease, lease_payment, deposit, vendor_credit, payment_batch. example: invoice advance_to: type: integer minimum: 0 description: > New current_value for the counter. Next-issued = advance_to + 1. Must be >= existing current_value (monotonic; decrement not allowed). example: 342665 prefix: type: string maxLength: 20 description: > Required only when creating a new counter row (entity does not have one yet). Existing rows preserve their prefix. padding: type: integer minimum: 1 maximum: 12 description: | Optional. Used only when creating a new counter row. Defaults to 7. MigrationCounterAdvanceBatch: type: object required: - counters description: Batch advance payload (up to 50 counters per call). properties: counters: type: array minItems: 1 maxItems: 50 items: $ref: '#/components/schemas/MigrationCounterAdvanceSingle' MigrationCounterAdvanceResult: type: object description: > Result envelope for counter advance. Each row in `results` reports independently; a failure on one counter does not roll back the others. properties: object: type: string enum: - migration_counter_advance_result total: type: integer succeeded: type: integer failed: type: integer results: type: array items: $ref: '#/components/schemas/MigrationCounterAdvanceItem' MigrationCounterAdvanceItem: type: object description: Result for one counter advance attempt. properties: counter_type: type: string previous_value: type: integer description: current_value before the call (0 if newly created). current_value: type: integer description: current_value after the call. prefix: type: string padding: type: integer version: type: integer advanced: type: boolean description: > true if current_value changed; false on idempotent no-op (existing value already >= advance_to). next_issued_preview: type: string description: > Padded preview of the next-to-be-issued document number, e.g. "INV-342666". error: type: string description: Present only on failure (validation, conflict, etc.). code: type: string description: Machine-readable error code. 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__ 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.