NFT DID Resolver

NFT is a DID method that uses the Ceramic network to resolve DID documents for NFTs

See CIP-94

Getting started

This implementation is still a prototype. Contributions are welcome!

By default, this package will resolve dids for both ERC721 and ERC1155 tokens on mainnet, if they are indexed by their respective public subgraphs:

• EIP721-Subgraph
• EIP1155-Subgraph

To resolve DIDs using your own subgraph, see Custom Subgraphs

Installation

$ npm install nft-did-resolver
// or
$ yarn add nft-did-resolver

Usage

import NftResolver, { NftResovlerConfig } from 'nft-did-resolver'
import { Resolver } from 'did-resolver'
import Ceramic from '@ceramicnetwork/http-client'

const ceramic = new Ceramic() // connects to localhost:7007 by default

const config: NftResovlerConfig = {
  ceramic,
  subGraphUrls: { // optional, there are defaults for ethereum mainnet (erc721 and erc1155)
    // CAIP2 ChainID (below is ETH mainnet)
    'eip155:1': {
      // Asset namespace
      erc721: 'https://api.thegraph.com/subgraphs/name/xxx/yyy',
      // erc721: 'http://localhost:8000/subgraphs/name/aoeu/qjkx' // also works!
      erc1155: 'https://api.thegraph.com/subgraphs/name/abc/xyz'
    },
    // Fake cosmos example
    'cosmos:nft-token-chainid': {
      erc721: 'https://api.thegraph.com/subgraphs/name/aaa/ooo'
    }
  }
}

// getResolver will return an object with a key/value pair of { 'nft': resolver }
// where resolver is a function used by the generic did resolver.
const nftResolver = NftResolver.getResolver(config)
const didResolver = Resolver(nftResolver)

const erc721result = await didResolver.resolve('did:nft:eip155.1_erc721.0xb300a43751601bd54ffee7de35929537b28e1488_2')
const erc1155result = await didResolver.resolve('did:nft:eip155.1_erc1155.0x06eb48572a2ef9a3b230d69ca731330793b65bdc_1')
console.log(erc721result, erc1155result)

Development

Start a ceramic daemon using the @ceramicnetwork/cli package, and a ganache ethereum rpc using the ganacle-cli package.

Then run tests:

$ npm test
$ yarn test

Custom Subgraphs

You may specify custom subgraph URLs in the configuration object as shown above in usage.

Note: custom subgraphs must conform to the below schemas at a minimum for assets to be resolved properly.

Note: At the moment, only ERC721 and ERC1155 asset namespaces are supported. However, CAIP2 chains beside ETH, for instance xDAI, with support for those namespaces are supported, as long as the subgraph schema is the same.

ERC721:

type Token @entity {
  id: ID!
  contract: TokenContract!
  owner: Owner!
  ...
}

type TokenContract @entity {
  id: ID!
  tokens: [Token!]! @derivedFrom(field: "contract")
  ...
}

type Owner @entity {
  id: ID!
  tokens: [Token!]! @derivedFrom(field: "owner")
  ...
}

ERC1155:

type Account @entity {
  id: ID!
  balances: [Balance!]! @derivedFrom(field: "account")
  ...
}
 
type TokenRegistry @entity {
  id: ID!
  tokens: [Token!]! @derivedFrom(field: "registry")
  ...
}

type Token @entity {
  id: ID!
  registry: TokenRegistry!
  identifier: BigInt!
  balances: [Balance!]! @derivedFrom(field: "token")
  ...
}
 
type Balance @entity {
  id: ID!
  token: Token!
  account: Account!
  ...
}

For more information on writing schemas for GraphProtocol, check out their documentation.

DID Specs

The token DIDs are prefixed with did:nft:, and the latter half is a modified CAIP format.

ERC721 (CAIP-22)

DID: did:nft:{chainNamespace}.{chainReference}_erc721.{contractAddress}_{tokenId}

CAIP-22: {chainNamespace}:{chainReference}/erc721:{contractAddress}/{tokenId}

ERC1155 (CAIP-29)

DID: did:nft:{chainNamespace}.{chainReference}_erc1155.{contractAddress}_{tokenId}

CAIP-29: {chainNamespace}:{chainReference}/erc1155:{contractAddress}/{tokenId}

Conversions

DID->CAIP

const caip = did.substr(8).replace(/_/g, '/').replace(/\./g, ':')

CAIP->DID

const did = `did:nft:${caip.replace(/\//g, '_').replace(/:/g, '.')}`

Contributing

We are happy to accept small and large contributions. Make sure to check out the Ceramic specifications for details of how the protocol works.

License

Apache-2.0 OR MIT