[Home](./index.md) > [@firebase/firestore](./firestore.md) > [/](./firestore_.md) > [addDoc](./firestore_.adddoc.md) ## addDoc() function Add a new document to specified `CollectionReference` with the given data, assigning it a document ID automatically. Signature: ```typescript export declare function addDoc(reference: CollectionReference, data: T): Promise>; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | reference | [CollectionReference](./firestore_.collectionreference.md)<T> | A reference to the collection to add this document to. | | data | T | An Object containing the data for the new document. | Returns: Promise<[DocumentReference](./firestore_.documentreference.md)<T>> A Promise resolved with a `DocumentReference` pointing to the newly created document after it has been written to the backend (Note that it won't resolve while you're offline).