Attachments are binary data files that can be attachment to an RxDocument, like a file that is attached to an email.

Using attachments instead of adding the data to the normal document, ensures that you still have a good performance when querying and writing documents, even when a big amount of data, like an image file has to be stored.

  • You can store string, binary files, images and whatever you want side by side with your documents.
  • Deleted documents automatically loose all their attachments data.
  • Not all replication plugins support the replication of attachments.
  • Attachments can be stored encrypted.

Add the attachments plugin

To enable the attachments, you have to add the attachments plugin.

import { addRxPlugin } from 'rxdb';
import { RxDBAttachmentsPlugin } from 'rxdb/plugins/attachments';

Enable attachments in the schema

Before you can use attachments, you have to ensure that the attachments-object is set in the schema of your RxCollection.

const mySchema = {
    version: 0,
    type: 'object',
    properties: {
        // .
        // .
        // .
    attachments: {
        encrypted: true // if true, the attachment-data will be encrypted with the db-password

const myCollection = await myDatabase.addCollections({
    humans: {
        schema: mySchema


Adds an attachment to a RxDocument. Returns a Promise with the new attachment.

const attachment = await myDocument.putAttachment(
        id,     // (string) name of the attachment like 'cat.jpg'
        data,   // (string|Blob|Buffer) data of the attachment
        type    // (string) type of the attachment-data like 'image/jpeg'
    true // (boolean, optional, default=true) skipIfSame:If true and attachment already exists with same data, the write will be skipped


Returns an RxAttachment by its id. Returns null when the attachment does not exist.

const attachment = myDocument.getAttachment('cat.jpg');


Returns an array of all attachments of the RxDocument.

const attachments = myDocument.allAttachments();


Gets an Observable which emits a stream of all attachments from the document. Re-emits each time an attachment gets added or removed from the RxDocument.

const all = [];
    attachments => all = attachments


The attachments of RxDB are represented by the type RxAttachment which has the following attributes/methods.


The RxDocument which the attachment is assigned to.


The id as string of the attachment.


The type as string of the attachment.


The length of the data of the attachment as number.


The md5-sum of the attachments data as string.


The revision-number of the attachment as number.


Removes the attachment. Returns a Promise that resolves when done.

const attachment = myDocument.getAttachment('cat.jpg');
await attachment.remove();


Returns a Promise which resolves the attachment's data as Blob or Buffer. (async)

const attachment = myDocument.getAttachment('cat.jpg');
const blobBuffer = await attachment.getData();


Returns a Promise which resolves the attachment's data as string.

const attachment = await myDocument.getAttachment('cat.jpg');
const data = await attachment.getStringData();

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