Iota Browser

Install Dependency

Package: @affinidi-tdk/iota-browser

npm install @affinidi-tdk/iota-browser --save

Check the latest version on the npm registry or view the source on GitHub.

Implementation Note

The Iota Browser library is a browser-only module; make sure to invoke the library on the client side. It creates a WebSocket connection and requires access to the browser window object to initiate a data request to the Affinidi Vault.

If you are using a framework that has a server-side rendering like NextJS, you can do the following:

• Window Checking
• Dynamic Import

useEffect(() => {
    if (typeof window !== 'undefined') {
        const initIota = async () => {
            const iotaSession = new Session({ credentials: iotaCredentials });
            await iotaSession.initialize();

        }
        initIota()
    }
}

import dynamic from 'next/dynamic'

const IotaClientComponent = dynamic(() => import('components/Iota/IotaClientComponent'), {
  ssr: false,
})

export default function Page() {
  return <IotaClientComponent />
}

Classes and Methods

Session

Sets up and manages the request to Affinidi Iota Framework. To initialise Session, generate the Iota Credential using the iota-core package and pass it as a parameter.

Constructor parameters

Example

const credentials = await getIotaCredentials(configurationId)
const iotaSession = new Session({ credentials })

getIotaCredentials is an async function that calls an exposed API endpoint from the backend to generate the Iota Credentials.

initialize

Initialises the Iota Session, opening a WebSocket that listens for callback events from the Affinidi Iota Framework service.

No parameters required.

Example

const iotaSession = new Session({ credentials })

await iotaSession.initialize()

prepareRequest

Creates an IotaRequest object from the initialised Iota Session. The response contains the signed Request Token for the Affinidi Vault to request data.

Parameters

Example

const request = await iotaSession.prepareRequest({ queryId })

IotaRequest

Initiates the data-sharing flow between the application and Affinidi Vault. Obtained from the prepareRequest method.

openVault

Opens Affinidi Vault with the signed Request Token and queries the data.

Parameters

Example

const iotaRequest = await iotaSession.prepareRequest({ queryId })

iotaRequest.openVault({ mode: openMode })

getResponse

Retrieves the response from Affinidi Vault through the open WebSocket.

No parameters required.

Example

const iotaRequest = await iotaSession.prepareRequest({ queryId })
iotaRequest.openVault({ mode: openMode })

const response = await iotaRequest.getResponse()

Check for Iota Request Response

To check if an Iota Request is a valid response and parse the Verifiable Presentation (verifiablePresentation), use the IotaResponse instance.

Example

const iotaRequest = await iotaSession.prepareRequest({ queryId })
iotaRequest.openVault({ mode: openMode })

const response = await iotaRequest.getResponse()

if (response instanceof IotaResponse) {
  // parse the Verifiable Presentation and do business logic
}

Check for Iota Request Error

To check if an Iota Request has failed and parse the error information, use the IotaError instance.

Example

try {
  const iotaCredentials = await getIotaCredentials()
  const iotaSession = new Session({ credentials: iotaCredentials })
  await iotaSession.initialize()
} catch (error) {
  if (error instanceof IotaError) {
    console.log(error.code)
  }
}