@cardstack/did-resolver
v1.0.54
Published
A javascript resolver for the cardstack DID method
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cardstack DID Resolver
This library is intended to resolve Cardstack Decentralized Identifiers to their associated DID Documents.
It supports the proposed Decentralized Identifiers spec from the W3C Credentials Community Group.
It requires the did-resolver
library, which is the primary interface for resolving DIDs.
There is a python-equivalent version for Cardstack services in another subpackage.
DID method
Cardstack supports a family of DIDs that begin with did:cardstack:
DID Document
The DID resolver takes the DID and constructs the DID Document.
Resolving a DID document
The resolver presents a simple resolver()
function that returns a ES6 Promise returning the DID
document.
import { Resolver } from 'did-resolver'
import { getResolver } from '@cardstack/did-resolver'
const cardstackResolver = getResolver()
const didResolver = new Resolver({
...cardstackResolver
//...you can flatten multiple resolver methods into the Resolver
})
didResolver.resolve('did:cardstack:1p123456...').then(result => console.log(result.didDocument))
// You can also use async/await syntax
(async () => {
const result = await didResolver.resolve('did:cardstack:1p123456...');
console.log(result.didDocument);
})();
The resolved DIDDocument will have a alsoKnownAs
property that is an array containing a URL to a json document with details of the resource.
Encoding a DID
This package exports an encodeDID
function that can be used to create a DID string.
import { encodeDID } from '@cardstack/did-resolver'
let did = encodeDID({ type: 'SupplierInfo' });
console.log(did); // => 'did:cardstack:1sicq4U2Dq678AtWufbxJBg7120d206cf61b50d4'
By default, encodeDID
will provide the version and generate a uniqueId for you, but you can also specify them:
import { encodeDID } from '@cardstack/did-resolver'
import shortUuid from 'short-uuid';
let did = encodeDID({ type: 'SupplierInfo', version: 5, uniqueId: shortUuid.generate() });
About the cardstack method identifier format
An example of a cardstack method identifier is:
1sicq4U2Dq678AtWufbxJBg7120d206cf61b50d4
12[---------3----------][------4-------]
Let's break down the parts:
First character: represents the version, uses "0"-"9" for 0-9, "A-Z" for 10-35, "a-z" for 36-61
Second character: represents the type, 'p' for PrepaidCardCustomization, 'm' for MerchantInfo, 's' for SupplierInfo, 'r' for RewardRule
Next 22 characters: unique identifier, you can generate this using
shortUuid.generate()
Last 16 characters: checksum, hash of the identifier up to this point, calculated using shake_128 with 64 bits of output