Value:
| Readonly<{ data: string; kind: "string" }>
| Readonly<{ data: boolean; kind: "bool" }>
| Readonly<{ data: bigint; kind: "int64" }>
| Readonly<{ data: number; kind: "double" }>
| Readonly<{ data: Uint8Array; kind: "bytes" }>
| Readonly<{ data: string; kind: "json" }>
Contains one validated SDK value before protocol mapping.