> ## Documentation Index > Fetch the complete documentation index at: https://docs.joinluminous.com/llms.txt > Use this file to discover all available pages before exploring further. # Set custom field values on a fulfillment order > Sets one or more custom field values on a fulfillment order. Each key in the `fields` object must match the **label** of a pre-configured `CustomField` definition that is set up for `FulfillmentOrder` records. **Unlike** the tote-ID endpoint, this endpoint does **not** auto-create field definitions — tenants must configure them in advance under Settings → Custom Fields. When `set_on_sales_order=true`, the same field values are also written to the associated sales order (if a matching `SalesOrder` custom field definition exists). Returns **404** if any label has no matching definition, or the matched definition isn't configured for the target record type. ## OpenAPI ````yaml /api-reference/build.yaml put /fulfillment-orders/{fulfillmentOrderId}/custom-fields openapi: 3.0.0 info: title: Luminous API version: 1.0.0 description: API documentation for Luminous servers: - url: https://{companyName}.api.joinluminous.com/external/api/v1 variables: companyName: default: companyName description: Your company-specific subdomain security: [] tags: - name: Products description: Get and manage products - name: Pricing description: Manage price schedules, levels, and customizations - name: BOMs description: Manage Bills of Materials (BOMs) - name: Labels description: Label rendering via Labelary ZPL service - name: Companies description: Manage business accounts and their associated data - name: Contacts description: Manage contact information for individuals - name: Suppliers description: Manage suppliers (factories) — vendors used on purchase orders - name: Supplier SKUs description: Manage per-supplier SKU and unit-cost overrides for products - name: Locations description: Manage warehouses and locations - name: Inventory description: Get and adjust product stock levels - name: Lots description: Create, update, and delete product lots (batches) - name: Transfer Orders description: Manage transfer orders - name: Fulfillment Orders description: Manage fulfillment orders and picklists - name: Purchase Orders description: Get and modify purchase orders - name: Receiving Reports description: Manage receiving reports - name: Payment Obligations description: Manage payment obligations for purchase orders - name: Sales Orders description: Manage sales orders and sales order shipments - name: Purgatory description: >- Inspect and resolve non-posted sales orders in the purgatory staging workflow - name: PickFlow Shipping description: >- Provider-agnostic shipping rates, services, packages, and label purchase for PickFlow - name: Cycle Counts description: >- Create, drive, and post PickFlow cycle counts — batches, per-warehouse sessions, and CSV import/export - name: Print Stations description: List paired print stations and enqueue print jobs to them - name: Invoices description: Get and manage invoices - name: Work Orders description: >- Manage work orders — production lifecycle, steps, materials, links, shipments, and comments - name: Production Batches description: Group and manage work orders as production batches - name: Bills description: >- Accounts payable bill management, payments, attachments, allocations, and variance - name: Prepayments description: Manage vendor prepayments and applications - name: Vendor Credits description: Manage vendor credits and applications - name: Vendor Returns description: Manage vendor returns and credit generation - name: Customer Returns description: Manage customer returns (sales returns), receiving, and restock behavior - name: Stock Snapshot description: Point-in-time stock snapshots with export support - name: Consumption description: Consumption reports and exports - name: Inventory Aging description: Cost-layer-based inventory aging reports - name: Bills Reports description: Accounts payable bills aging reports - name: Forecast description: Materialized forecast data - name: Reports description: Close the books, inventory discrepancy, transaction COGS, and EDI reports - name: Tags description: Add/remove tags across various resources - name: Custom Fields description: Get and set custom fields across various resources - name: Currency description: Currency configuration, exchange rates, and conversion - name: Integration Mappings description: Manage integration mappings for external systems - name: Integration Field Mappings description: Manage field-level mappings between Luminous and external systems paths: /fulfillment-orders/{fulfillmentOrderId}/custom-fields: put: tags: - Fulfillment Orders summary: Set custom field values on a fulfillment order description: > Sets one or more custom field values on a fulfillment order. Each key in the `fields` object must match the **label** of a pre-configured `CustomField` definition that is set up for `FulfillmentOrder` records. **Unlike** the tote-ID endpoint, this endpoint does **not** auto-create field definitions — tenants must configure them in advance under Settings → Custom Fields. When `set_on_sales_order=true`, the same field values are also written to the associated sales order (if a matching `SalesOrder` custom field definition exists). Returns **404** if any label has no matching definition, or the matched definition isn't configured for the target record type. operationId: setFulfillmentOrderCustomFields parameters: - in: path name: fulfillmentOrderId required: true schema: type: integer description: Fulfillment order ID requestBody: required: true content: application/json: schema: type: object required: - fields properties: fields: type: object minProperties: 1 description: > Map of custom field label → value. The label must exactly match a pre-configured `CustomField` definition for `FulfillmentOrder`. additionalProperties: {} example: Tote ID: TOTE-001 Priority: High set_on_sales_order: type: boolean default: false description: > When `true`, also write the same field values to the associated sales order (requires matching definitions on `SalesOrder`). responses: '200': description: Custom fields set successfully content: application/json: schema: type: object properties: message: type: string data: type: object properties: fulfillment_order_id: type: integer sales_order_id: type: integer nullable: true order_key: type: string nullable: true set_on_sales_order: type: boolean fields: type: object additionalProperties: {} '401': description: Unauthorized content: application/json: schema: type: object properties: message: type: string '404': description: >- Fulfillment order not found, or no custom field definition matches a given label content: application/json: schema: type: object properties: message: type: string '422': description: Type validation error (e.g. invalid dropdown option) content: application/json: schema: type: object properties: message: type: string security: - BearerAuth: [] components: securitySchemes: BearerAuth: type: http scheme: bearer description: >- Authenticate using a bearer token. To create a token, navigate to /settings/api-tokens and click Create API Token. ````