# Type Alias: ExternalItemFunction

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title: "Type Alias: ExternalItemFunction"
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- Type: {((data: ExternalItemFunctionData, callback: (err?: null | Error, result?: string | boolean | string[] | ExternalItemValueObjectKnown & ExternalItemValueObjectUnknown) => void) => void) | ((data: ExternalItemFunctionData) => Promise<ExternalItemValue>)}