Wallet Attached Storage Client (@did-coop/wallet-attached-storage)

A Wallet Attached Storage Javascript/TypeScript client for Node, browser and React Native.

Table of Contents

• Background
• Security
• Install
• Usage
• Contribute
• License

Background

See in progress spec: https://did-coop.github.io/wallet-attached-storage-spec/

App Identity and Key Management

To use Wallet Attached Storage (to provision data spaces, to create collections, and to read and write resources), the application or service using this client will need its own cryptographically provable identity (in the form of a DID).

At minimum, this means that the app or service using this client will need to create and manage its own public-private key pair. The challenges and security considerations of cryptographic key management are beyond the scope of this usage document, but roughly:

• For in browser client-only Single Page Applications (SPAs), the app's identity is ephemeral -- essentially a key pair will be generated for each new user session, and stored in the browser.

• For traditional server side web applications, it is recommended that the app's DID and key pairs are managed securely, on the server side, preferably using an HSM (Hardware Security Module).

• For mobile apps, key pairs may be generated during setup, and can take advantage of the mobile operating system's keychain and encrypted app storage.

Security

TBD

Install

• Node.js 18+ is recommended.

NPM

To install via NPM:

npm install @did-coop/wallet-attached-storage

Development

To install locally (for development):

git clone https://github.com/did-coop/wallet-attached-storage.git
cd wallet-attached-storage
npm install

Usage

This client assumes:

• a remote Wallet Attached Storage server is available
• the app is able to create and store a public-private key pair, see the App Identity and Key Management section for more details.

Example key pair generation (for an in-browser SPA), for persistence in local storage.

import { Ed25519Signer } from '@did.coop/did-key-ed25519'

const appDidSigner = await Ed25519Signer.generate()

Example storing and loading:

// Serialize to JSON for storage
const exportedKeyPair = appDidSigner.toJSON()
localStorage.setItem('app-DID', JSON.stringify(exportedKeyPair))

// Load from storage and turn back into a DID Signer
const loadedKeyPair = localStorage.getItem('app-DID')
const appDidSigner = Ed25519Signer.fromJSON(loadedKeyPair)

Create a Wallet Attached Storage Client, connect it to a remote url:

import { WalletStorage } from '@did-coop/wallet-attached-storage'

const url = 'https://data.pub' // load this from config

let storage
try {
  storage = WalletStorage.connect({ url, signer: appDidSigner })
} catch (e) {
  console.error('Error connecting:', e)
  throw e
}

Now you can read and write resources to and from collections:

// Create a reference to the Credentials collection (note that no API calls are
//   made yet)
const credentials = storage.collection('credentials')

// Iterate through the collection, fetch the resources
for await (const resource of credentials) {
  const response = await resource.get()
  const vc = await response.json()
  console.log(JSON.stringify(vc, null, 2))
}

// Upload a VC
await credentials.resource().put(
  new Blob(JSON.stringify(vc), { type: 'application/vc' })
)

// Upload Evidence / Documents
await storage.collection('documents')
  .resource().put(getDocumentBlob())

Contribute

PRs accepted.

If editing the Readme, please conform to the standard-readme specification.

License

MIT License © 2025 DID.coop.