> ## 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. # List activity for a resource > Returns the activity events scoped to one resource, such as an account, product, or order, equivalent to filtering the activity list by resource type and id. Supports the same pagination and filter parameters as the main activity list. ## OpenAPI ````yaml /openapi.yaml get /resources/{type}/{id}/activity 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: /resources/{type}/{id}/activity: get: tags: - Activity summary: List activity for a resource description: >- Returns the activity events scoped to one resource, such as an account, product, or order, equivalent to filtering the activity list by resource type and id. Supports the same pagination and filter parameters as the main activity list. operationId: listResourceActivity parameters: - in: path name: type required: true schema: type: string description: Resource type (e.g. account, product, order, journal_entry). - in: path name: id required: true schema: type: string format: uuid description: Resource UUID. - name: limit in: query schema: type: integer minimum: 1 maximum: 100 default: 20 - in: query name: starting_after schema: type: string description: Cursor for pagination. - in: query name: actor_type schema: type: string enum: - user - api_key - system - in: query name: actor_id schema: type: string responses: '200': description: Paginated list of activity events for the resource. content: application/json: schema: type: object properties: object: type: string enum: - list data: type: array items: $ref: '#/components/schemas/ActivityEvent' has_more: type: boolean next_cursor: type: string nullable: true url: type: string '400': $ref: '#/components/responses/Error' '401': $ref: '#/components/responses/Error' '403': $ref: '#/components/responses/Error' security: - ApiKeyAuth: [] components: schemas: ActivityEvent: type: object description: | A single activity log event (R11 envelope). Activity events are created automatically by canonical handlers via logActivity(). The public id uses the format act_ (UUID without dashes, prefixed with 'act_'). Internal-only fields stripped from this envelope: prev_hash, entry_hash (audit chain integrity), archived_at, archive_uri (S3 archive pointer). These fields are admin-only and not exposed via the public API. required: - id - object - entity_id - created_at - actor - action - resource_type properties: id: type: string description: Public activity id in format act_. example: act_550e8400e29b41d4a716446655440000 object: type: string enum: - activity_event entity_id: type: string format: uuid description: Entity this event belongs to (Layer 1 scoping). created_at: type: string format: date-time description: Timestamp when the event was created (immutable; point-in-time). actor: $ref: '#/components/schemas/ActivityActor' action: type: string description: > Action string from the canonical ACTION_VALUES vocabulary (utils/activity-actions.mjs). Examples: account.created, product.updated, order.fulfilled, journal_entry.posted. example: account.created resource_type: type: string description: >- Type of the resource this event concerns (e.g. account, product, order). example: account resource_id: type: string format: uuid nullable: true description: >- UUID of the resource this event concerns (null for entity-level events). resource_label: type: string nullable: true description: >- Human-readable label of the resource at time of event (denormalized snapshot). description: type: string nullable: true description: Human-readable description of what happened. severity: type: string enum: - info - notice - warning - critical description: Severity level of the event. example: info outcome: type: string enum: - success - failure - denied description: Outcome of the action. example: success error_code: type: string nullable: true description: Error code if outcome=failure (null for success). request_id: type: string nullable: true description: HTTP request_id for tracing (maps to CloudWatch log stream). metadata: type: object description: | Additional structured metadata for this event. The internal _actor block is stripped and surfaced as the top-level actor field. diff: $ref: '#/components/schemas/ActivityDiff' ActivityActor: type: object description: > The actor who performed the action. actor.label is a point-in-time snapshot (denormalized at insert time; the live user may have been renamed since). properties: type: type: string enum: - user - api_key - system description: >- Actor type. user=Cognito JWT caller; api_key=public API key; system=cron/scheduler. id: type: string nullable: true description: >- Actor id (Cognito user_id for user; entity_api_keys.id for api_key; null for system). label: type: string nullable: true description: >- Human-readable label at time of action (e.g. 'Jane Smith' or 'API: Migration Key'). on_behalf_of: nullable: true description: > When actor.type=api_key, the human user who created/owns the key (on_behalf_of.type='user'). Null for user and system actors. properties: type: type: string enum: - user id: type: string nullable: true description: on_behalf_of user_id. label: type: string nullable: true description: on_behalf_of display_name. ActivityDiff: type: object description: State snapshot diff for the activity event. properties: before: nullable: true description: State before the action (null if not captured or not applicable). after: nullable: true description: State after the action (null if not captured or not applicable). 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.