File Storage

What is File Storage and what is it for?

File Storage is a reusable module that lets a Holochain app upload files into its own shared data store and read them back. It exists so that builders do not have to write file handling from scratch, and it ships both the backend zome and browser components for the interface.

File Storage is a small module published by holochain-open-dev for Holochain apps, rather than an app of its own. Its README describes a zome to create and retrieve files, built to be dropped into somebody else's DNA and to assume as little as possible about that DNA. Alongside the zome it ships an npm package of native web components, so the same module covers the backend pieces and a browser interface.

An app that wants people to publish documents, images or other files would otherwise have to write that storage layer itself. This module supplies it: files are uploaded into the app's shared data store, and the accompanying components give a ready-made upload and browse interface. The project's own documentation notes that uploading and downloading are handled with built-in chunking, and the README states that the module currently assumes a single DNA per app holds the files.

A typical adoption adds the zome as a Cargo dependency, registers it in the app's dna.yaml under the name file_storage, and installs the UI package with npm. In that last step the elements expect a running conductor at ws://localhost:8888 during development, and the repository includes a working demo page to copy from. The Storybook at holochain-open-dev.github.io/file-storage documents the components, and the README covers the zome side.

From 3 public sources, checked 23 September 2026.