> ## 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. # Relink migrated inventory transaction reference_id to Arcus order UUIDs > A migrated historical inventory transaction is born with `reference_id = NULL` because Phase 6 (orders/invoices) runs concurrently or after Phase 4 (inventory transactions); the Arcus order UUID does not exist yet at ITX-insert time. Native Arcus order fulfillments set `reference_id` = the Arcus order UUID, and the per-order drill-through resolves inventory movements via that UUID. This endpoint is the corrective reconciliation pass (Phase 9c) run AFTER orders and invoices are migrated. The caller supplies a batch of items, each mapping the Versa source transaction id (`external_id`, carried on `inventory_transactions.transaction_id`) to its Arcus order UUID (`source_id`). **Lookup key.** The column `inventory_transactions.transaction_id` holds the Versa source transaction id (set by `recordHistoricalInventoryTransaction`). There are no `external_source` / `external_id` columns on this table. **Strict-resolve safety.** `source_id` must be a UUID that resolves to an order in the entity. A non-UUID or non-resolving value is rejected, never written. **Idempotent.** When an ITX already carries the target `reference_id`, the item returns `relinked=false` (no-op). Re-running the whole pass is safe. **Provenance guard.** Only ITXs with `reference_type = 'versa_migration'` can be relinked. Native Arcus ITXs are never matched. **Pure UPDATE.** Touches only `inventory_transactions.reference_id`. No quantity, cost, balance, or FIFO layer is modified. **Scope:** `migration:write`. ## OpenAPI ````yaml /openapi.yaml post /entities/{entity_id}/migration/inventory-transactions/relink-source 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. 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/inventory-transactions/relink-source: post: tags: - Migration summary: Relink migrated inventory transaction reference_id to Arcus order UUIDs description: > A migrated historical inventory transaction is born with `reference_id = NULL` because Phase 6 (orders/invoices) runs concurrently or after Phase 4 (inventory transactions); the Arcus order UUID does not exist yet at ITX-insert time. Native Arcus order fulfillments set `reference_id` = the Arcus order UUID, and the per-order drill-through resolves inventory movements via that UUID. This endpoint is the corrective reconciliation pass (Phase 9c) run AFTER orders and invoices are migrated. The caller supplies a batch of items, each mapping the Versa source transaction id (`external_id`, carried on `inventory_transactions.transaction_id`) to its Arcus order UUID (`source_id`). **Lookup key.** The column `inventory_transactions.transaction_id` holds the Versa source transaction id (set by `recordHistoricalInventoryTransaction`). There are no `external_source` / `external_id` columns on this table. **Strict-resolve safety.** `source_id` must be a UUID that resolves to an order in the entity. A non-UUID or non-resolving value is rejected, never written. **Idempotent.** When an ITX already carries the target `reference_id`, the item returns `relinked=false` (no-op). Re-running the whole pass is safe. **Provenance guard.** Only ITXs with `reference_type = 'versa_migration'` can be relinked. Native Arcus ITXs are never matched. **Pure UPDATE.** Touches only `inventory_transactions.reference_id`. No quantity, cost, balance, or FIFO layer is modified. **Scope:** `migration:write`. operationId: postMigrationInventoryTransactionRelinkSource 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: $ref: '#/components/schemas/MigrationInventoryTransactionRelinkBatch' examples: batch: summary: Relink a batch of migrated ITXs value: items: - external_id: '123456' source_id: 6b1e9a4f-1d2c-4f8e-9c8a-8b1d2e3f4a5b - external_id: '123457' source_id: 7c2f0b5e-2e3d-5f9f-ad9b-9c2e3f4a5b6c responses: '200': description: ITX source-relink result content: application/json: schema: $ref: '#/components/schemas/MigrationInventoryTransactionRelinkResult' '400': $ref: '#/components/responses/Error' '401': $ref: '#/components/responses/Error' '403': $ref: '#/components/responses/Error' security: - ApiKeyAuth: [] components: schemas: MigrationInventoryTransactionRelinkBatch: type: object required: - items description: Batch ITX source-relink payload (up to 500 items per call). properties: items: type: array minItems: 1 maxItems: 500 items: $ref: '#/components/schemas/MigrationInventoryTransactionRelinkItem' MigrationInventoryTransactionRelinkResult: type: object description: | Result envelope for ITX source relink. Each row in `results` reports independently; a failure on one item does not roll back the others. Pure column UPDATE on reference_id. No quantity, cost, balance, or FIFO layer is modified. properties: object: type: string enum: - migration_itx_source_relink_result total: type: integer relinked: type: integer already_linked: type: integer not_found: type: integer failed: type: integer results: type: array items: $ref: '#/components/schemas/MigrationInventoryTransactionRelinkResultItem' MigrationInventoryTransactionRelinkItem: type: object required: - external_id - source_id description: One ITX source-relink request. properties: external_id: type: string description: > The Versa source transaction id stored in `inventory_transactions.transaction_id` (set by `recordHistoricalInventoryTransaction` as `sourceTxnId`). Matched alongside the entity_id and `reference_type = 'versa_migration'` to locate the migrated ITX. source_id: type: string format: uuid description: > The Arcus order UUID to write into `inventory_transactions.reference_id`. Strictly validated: must be a UUID that resolves to an order in the entity. A non-UUID or non-resolving value is rejected, never written. MigrationInventoryTransactionRelinkResultItem: type: object description: Per-item result of an ITX source-relink attempt. properties: external_id: type: string inventory_transaction_id: type: string format: uuid description: >- The Arcus inventory_transaction UUID matched (omitted when not found). source_id: type: string format: uuid description: The current reference_id after the call. relinked: type: boolean description: > true if reference_id was updated; false on idempotent no-op (the ITX already carried the target reference_id). error: type: string description: Present only on failure. code: type: string description: Machine-readable error code. hint: type: string 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. ````