[Home](./index.md) > [@firebase/storage-types](./storage-types.md) > [StorageObserver](./storage-types.storageobserver.md) ## StorageObserver interface A stream observer for Firebase Storage. Signature: ```typescript export interface StorageObserver ``` ## Properties | Property | Type | Description | | --- | --- | --- | | [complete](./storage-types.storageobserver.complete.md) | CompleteFn \| null | | | [error](./storage-types.storageobserver.error.md) | (error: [FirebaseStorageError](./storage-types.firebasestorageerror.md)) => void \| null | | | [next](./storage-types.storageobserver.next.md) | NextFn<T> \| null | |