writing-inbound-jsonata

To map custom fields in inbound 850 JSONata, use the transaction.userDefinedFields structure. The critical rule is that this object replaces rather than merges, so you must include all desired custom fields in a single write to avoid accidentally dropping existing values.

Custom date fields (custbody_*/custentity_*) fail during Sales Order save because NetSuite expects a specific text format. You must apply the _textFields workaround in your JSONata expression to properly format these date fields and prevent the transaction save from failing.

To resolve contacts and item identifiers from raw Mosaic EDI 850 input, use pre-registered helper functions like $lookupContact, $lookupItems, and $lookupRecords within your JSONata expression. These functions query NetSuite data directly during the mapping process.

Yes, the Orderful NetSuite SuiteApp supports overriding default values by starting from $defaultValues and applying the correct ~> overlay pattern in your JSONata expression. This workflow allows you to safely change specific fields like contacts and custom fields while preserving required defaults.

The safest way to populate custom fields in a NetSuite 850 JSONata mapping is to construct the complete userDefinedFields object and apply it via the ~> overlay pattern onto $defaultValues. Because userDefinedFields replaces rather than merges, providing the full object prevents unintended data loss.