[Home](./index.md) > [@firebase/firestore](./firestore.md) > [lite](./firestore_lite.md) > [WriteBatch](./firestore_lite.writebatch.md) > [set](./firestore_lite.writebatch.set.md) ## WriteBatch.set() method Writes to the document referred to by the provided [DocumentReference](./firestore_.documentreference.md). If the document does not exist yet, it will be created. Signature: ```typescript set(documentRef: DocumentReference, data: T): WriteBatch; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | documentRef | [DocumentReference](./firestore_lite.documentreference.md)<T> | A reference to the document to be set. | | data | T | An object of the fields and values for the document. | Returns: [WriteBatch](./firestore_lite.writebatch.md) This `WriteBatch` instance. Used for chaining method calls.