> ## 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. # Get a single audit log entry by ID > Returns the full detail of a single audit log entry by ID. Each entry includes the actor (user ID or API key ID), timestamp, resource type, resource ID, action performed, and a structured `changes` object showing before and after values for every modified field. Requires `audit:read` scope. ## OpenAPI ````yaml /openapi.yaml get /audit_log_entries/{id} 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: /audit_log_entries/{id}: get: tags: - AuditLog summary: Get a single audit log entry by ID description: > Returns the full detail of a single audit log entry by ID. Each entry includes the actor (user ID or API key ID), timestamp, resource type, resource ID, action performed, and a structured `changes` object showing before and after values for every modified field. Requires `audit:read` scope. operationId: getAuditLogEntry parameters: - name: id in: path required: true schema: type: string format: uuid - name: expand in: query required: false schema: type: array items: type: string enum: - actor - resource - diff - chain explode: true description: | actor: resolve actor name/email from users table. resource: join full resource row (product, order, account, etc.). diff: include before_state, after_state, diff JSONB. chain: include prev_hash, entry_hash, archived_at. responses: '200': description: Single audit log entry content: application/json: schema: $ref: '#/components/schemas/AuditLogEntry' '401': $ref: '#/components/responses/Error' '403': $ref: '#/components/responses/Error' '404': $ref: '#/components/responses/Error' security: - ApiKeyAuth: [] components: schemas: AuditLogEntry: type: object description: > A single audit log entry from activity_log. Audit log entries are created automatically by canonical handlers via logActivity() and are immutable. The public API exposes read-only access only (Rule 20, append-only design). Chain integrity fields (prev_hash, entry_hash) are included when expand[]=chain is requested. properties: id: type: string format: uuid object: type: string enum: - audit_log_entry entity_id: type: string format: uuid actor: type: object description: Actor who performed the action. Resolved from metadata.actor JSONB. properties: type: type: string enum: - user - api_key - system - webhook id: type: string nullable: true label: type: string nullable: true name: type: string nullable: true description: Present when expand[]=actor. email: type: string nullable: true description: Present when expand[]=actor. on_behalf_of_user_id: type: string nullable: true action: type: string description: Dot-namespaced action slug, e.g. order.created. resource: type: object properties: type: type: string id: type: string format: uuid nullable: true label: type: string nullable: true description: type: string nullable: true metadata: type: object nullable: true description: >- Arbitrary JSONB payload. Internal keys (_actor, _api_key_id, etc.) prefixed with underscore. ip_address: type: string nullable: true user_agent: type: string nullable: true session_id: type: string nullable: true request_id: type: string nullable: true severity: type: string enum: - info - warning - critical - security nullable: true outcome: type: string enum: - success - failure nullable: true error_code: type: string nullable: true before_state: nullable: true description: State before the action. Present when expand[]=diff. after_state: nullable: true description: State after the action. Present when expand[]=diff. diff: nullable: true description: Computed diff of before/after state. Present when expand[]=diff. _chain: type: object nullable: true description: Cryptographic chain fields. Present when expand[]=chain. properties: prev_hash: type: string nullable: true entry_hash: type: string nullable: true archived_at: type: string format: date-time nullable: true created_at: type: string format: date-time 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. ````