did-resolver

Javascript DID Resolver

This library is intended as a simple common interface for javascript applications to resolve DID documents from Decentralized Identifiers (DIDs).

This is intended to support the proposed Decentralized Identifiers spec from the W3C Credentials Community Group.

The library does not implement any specific DID method, but allows DID method implementors to release npm packages that applications can add.

Resolving a DID document

The resolver presents a simple resolver() function that returns a ES6 Promise returning the DID document.

import resolve from 'did-resolver'

resolve('did:uport:2nQtiQG6Cgm1GYTBaaKAgr76uY7iSexUkqX/some/path#fragment=123').then(doc => console.log)

// You can also use ES7 async/await syntax
const doc = await resolve('did:uport:2nQtiQG6Cgm1GYTBaaKAgr76uY7iSexUkqX/some/path#fragment=123')

Implementing a DID method

Each DID method will have it's own methods for looking up an identifier on it's respective blockchain or other decentralized storage mechanism.

A method implementer calls the registerMethod('methodname', resolver). where methodname is the method identifier. The resolver is a function that receives a DID and a parsed version of the DID. It returns a ES6 Promise that looks up the DID document.

import { registerMethod } from 'did-resolver'
registerMethod('mymethod', (did, parsed) => new Promise(resolve, reject) => {
  console.log(parsed)
  // {method: 'mymethod', id: 'abcdefg', did: 'did:mymethod:abcdefg/some/path#fragment=123', path: '/some/path', fragment: 'fragment=123'}
  const didDoc = ...// lookup doc
  resolve(didDoc)
})

The method resolver should register this so that just requiring it will register the method:

import resolve from 'did-resolver'
import MyMethod from 'mymethod-did-resolver'

resolve('did:mymethod:abcdefg/some/path#fragment=123').then(doc => console.log)