CAIP-10 Link client¶

A CAIP-10 Link is a stream that stores a proof that links a blockchain address to a Ceramic account (DID), using the CAIP-10 standard to represent blockchain addresses.

The stream-caip10-link module export a Caip10Link class used to link and unlink a DID to a CAIP-10 address using the CIP-7 "CAIP-10 Link" program.

Installation¶

npm install @ceramicnetwork/stream-caip10-link

Additional requirements¶

In order to load CAIP-10 Links, a Ceramic client instance must be available
To add/remove links, the client must also have an authenticated DID
An authentication provider is needed to sign the payload for the given CAIP-10 account, using the blockchain-utils-linking module that should be installed as needed:

npm install @ceramicnetwork/blockchain-utils-linking

Common usage¶

Load a link¶

In this example we load a Caip10Link for the account 0x054...7cb8 on the Ethereum mainnet blockchain (eip155:1).

import { CeramicClient } from '@ceramicnetwork/http-client'
import { Caip10Link } from '@ceramicnetwork/stream-caip10-link'

const ceramic = new CeramicClient()

async function getLinkedDID() {
  // Using the Ceramic client instance, we can load the link for a given CAIP-10 account
  const link = await Caip10Link.fromAccount(
    ceramic,
    '0x0544dcf4fce959c6c4f3b7530190cb5e1bd67cb8@eip155:1',
  )
  // The `did` property of the loaded link will contain the DID string value if set
  return link.did
}

Create a link¶

Here we can see the full flow of getting a user's Ethereum address, creating a link, and adding the users' DID account.

In this example we create a Caip10Link for the account 0x054...7cb8 on the Ethereum mainnet blockchain (eip155:1) and then associate it with the DID did:3:k2t6...ydki.

import { CeramicClient } from '@ceramicnetwork/http-client'
import { Caip10Link } from '@ceramicnetwork/stream-caip10-link'
import { EthereumAuthProvider } from '@ceramicnetwork/blockchain-utils-linking'

const ceramic = new CeramicClient()

async function linkCurrentAddress() {
  // First, we need to create an EthereumAuthProvider with the account currently selected
  // The following assumes there is an injected `window.ethereum` provider
  const addresses = await window.ethereum.request({
    method: 'eth_requestAccounts',
  })
  const authProvider = new EthereumAuthProvider(window.ethereum, addresses[0])

  // Retrieve the CAIP-10 account from the EthereumAuthProvider instance
  const accountId = await authProvider.accountId()

  // Load the account link based on the account ID
  const accountLink = await Caip10Link.fromAccount(
    ceramic,
    accountId.toString(),
  )

  // Finally, link the DID to the account using the EthereumAuthProvider instance
  await accountLink.setDid(
    'did:3:k2t6wyfsu4pg0t2n4j8ms3s33xsgqjhtto04mvq8w5a2v5xo48idyz38l7ydki',
    authProvider,
  )
}

Remove a link¶

Removing a link involves a similar flow to setting the DID, but using the clearDid method instead of setDid:

import { CeramicClient } from '@ceramicnetwork/http-client'
import { Caip10Link } from '@ceramicnetwork/stream-caip10-link'
import { EthereumAuthProvider } from '@ceramicnetwork/blockchain-utils-linking'

const ceramic = new CeramicClient()

async function unlinkCurrentAddress() {
  // First, we need to create an EthereumAuthProvider with the account currently selected
  // The following assumes there is an injected `window.ethereum` provider
  const addresses = await window.ethereum.request({
    method: 'eth_requestAccounts',
  })
  const authProvider = new EthereumAuthProvider(window.ethereum, addresses[0])

  // Retrieve the CAIP-10 account from the EthereumAuthProvider instance
  const accountId = await authProvider.accountId()

  // Load the account link based on the account ID
  const accountLink = await Caip10Link.fromAccount(
    ceramic,
    accountId.toString(),
  )

  // Finally, unlink the DID from the account using the EthereumAuthProvider instance
  await accountLink.clearDid(authProvider)
}