StopCustomData

Optional client-specific metadata for this stop. Use string keys; each value may be a string, number, boolean, array of JSON-safe values, or a nested object with the same rules. The serialized JSON must not exceed 2,000 characters.

Use this field to attach stop-specific references such as pickup numbers, BOL numbers, or PO numbers to individual stops rather than flattening them into load-level customData.

On update, sending this field replaces the stored value for that stop. Because routes are replaced wholesale on every write, omitting customData from a stop clears it to null. Send null explicitly to clear a previously stored value.