> ## 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. # Apply a reconciliation baseline > Anchors a bank account's reconciliation history at a given date and balance in one operation, reconciling GL lines and closing or adopting bank feed lines dated on or before the anchor except any ids passed in `keep_open_gl_line_ids` or `keep_open_bank_txn_ids`. Requires `accounting:write` scope, posts no journal entry, returns 422 with the variance math if the anchor does not balance unless `force: true` is set, and is idempotent when called again with the same date and balance. ## OpenAPI ````yaml /openapi.yaml post /bank-accounts/{id}/reconciliation-baseline 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: /bank-accounts/{id}/reconciliation-baseline: post: tags: - Accounting summary: Apply a reconciliation baseline description: >- Anchors a bank account's reconciliation history at a given date and balance in one operation, reconciling GL lines and closing or adopting bank feed lines dated on or before the anchor except any ids passed in `keep_open_gl_line_ids` or `keep_open_bank_txn_ids`. Requires `accounting:write` scope, posts no journal entry, returns 422 with the variance math if the anchor does not balance unless `force: true` is set, and is idempotent when called again with the same date and balance. operationId: applyReconciliationBaselineV1 parameters: - name: id in: path required: true schema: type: string format: uuid description: Bank account UUID. requestBody: required: true content: application/json: schema: type: object required: - baseline_date - baseline_balance properties: baseline_date: type: string format: date description: The cutover/anchor date (YYYY-MM-DD). baseline_balance: type: number description: The REAL bank statement balance at the anchor date. keep_open_gl_line_ids: type: array items: type: string format: uuid description: >- Journal-entry-line UUIDs to KEEP unreconciled (in-transit checks/deposits not yet cleared at the anchor). keep_open_bank_txn_ids: type: array items: type: string format: uuid description: >- Bank transaction UUIDs to KEEP unexcluded (feed lines that must remain matchable). Since 2026-09-18 this list also holds a line back from the adopt in step 3b, so a line the operator marks keep-open stays `matched` with no session instead of being filed under the anchor. force: type: boolean description: >- Accept a nonzero anchor variance (default false -> 422 when |variance| > $0.01). notes: type: string nullable: true description: Appended to the system session's notes (capped 500 chars). responses: '200': description: Idempotent re-run (same date + balance already stamped) content: application/json: schema: type: object properties: data: type: object properties: already_applied: type: boolean enum: - true baseline_date: type: string format: date baseline_balance: type: number reconciliation: type: object nullable: true '201': description: Baseline applied content: application/json: schema: type: object properties: data: type: object properties: reconciliation: type: object description: The completed system session row. baseline_date: type: string format: date baseline_balance: type: number gl_lines_reconciled: type: integer bank_transactions_excluded: type: integer deprecated: true description: >- ALWAYS 0 since 2026-09-21. The baseline no longer excludes anything; a pre-anchor line is a real bank event and is CLOSED under the session instead. Retained so existing readers do not break. Use `pre_anchor_closed_count`. pre_anchor_closed_count: type: integer description: >- Unreconciled feed lines dated on or before the anchor that this baseline CLOSED (step 3): `reconciliation_status` is set to `reconciled` and `reconciliation_id` to this session. They stay inside the bank register balance history, they leave the review queue, and the first statement after the anchor cannot count them again. pre_anchor_closed_net: type: number description: >- The signed net of those lines, in account currency. The wizard states this figure before the one press that cannot be re-anchored. adopted_sessionless_count: type: integer description: >- Already-matched feed lines dated on or before the anchor that this baseline session CLAIMED (step 3b). They are filed under the anchor and are not counted again by the first statement after it. orphan_matched_count: type: integer description: >- Feed lines that are `matched` with NO books link and no session, dated on or before the anchor. Never adopted (a baseline must not bury an unexplained claim); reported so they can be inspected. kept_open_matched_count: type: integer description: >- Already-matched feed lines the caller listed in `keep_open_bank_txn_ids`, held back from the adopt. ALWAYS 0 since 2026-09-21: such a request is now refused with 422 `keep_open_matched_row` before anything is written. Retained as a live assertion rather than a hardcoded zero. kept_open_gl_line_count: type: integer kept_open_bank_txn_count: type: integer math: type: object properties: gl_balance_at_baseline: type: number kept_open_total: type: number cleared_balance: type: number variance: type: number '400': description: invalid_baseline_date / invalid_baseline_balance / invalid UUID content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '401': $ref: '#/components/responses/Error' '403': $ref: '#/components/responses/Error' '404': $ref: '#/components/responses/Error' '409': description: >- baseline_already_exists (different params) OR reconciliation_in_progress (cancel it first) content: application/json: schema: $ref: '#/components/schemas/Error' '422': description: > `baseline_variance_nonzero` -- the body carries the full variance math; pass `force: true` to accept. `keep_open_matched_row` (2026-09-21) -- one or more ids in `keep_open_bank_txn_ids` name a line that is already `matched`. Both halves of a matched line are already claimed, so keeping it open would put its amount in the next statement twice and that session could never reach zero. NOTHING is written: no anchor, no session, no row state changes. The body carries `bank_transaction_ids`, a `rows` array (id, date, amount, description) capped at 50, and a `hint` naming the two ways forward. A kept-open line that is `unreconciled` is unaffected. content: application/json: schema: type: object properties: error: type: string enum: - baseline_variance_nonzero - keep_open_matched_row code: type: string bank_transaction_ids: type: array description: >- keep_open_matched_row only: the kept-open ids that are already matched. items: type: string format: uuid rows: type: array description: >- keep_open_matched_row only: up to 50 of those lines, enough to render them. items: type: object properties: id: type: string format: uuid transaction_date: type: string format: date amount: type: number description: type: string baseline_balance: type: number gl_balance_at_baseline: type: number kept_open_total: type: number cleared_balance: type: number variance: type: number hint: type: string security: - ApiKeyAuth: [] components: schemas: 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 Error: description: | Alias for ErrorEnvelope. Canonical error response shape used by all API endpoints. Refer to ErrorEnvelope for the full field definition. allOf: - $ref: '#/components/schemas/ErrorEnvelope' 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.