Class: Appendix

Defined in: packages/method/src/utils/appendix.ts:22

Implements 9. Appendix methods.

Appendix

Constructors

Constructor

new Appendix(): Appendix

Returns

Appendix

Methods

derefernceRootCapabilityIdentifier()

static derefernceRootCapabilityIdentifier(capabilityId): RootCapability

Defined in: packages/method/src/utils/appendix.ts:176

Implements 9.4.2 Dereference Root Capability Identifier.

This algorithm takes in capabilityId, a root capability identifier, and dereferences it to rootCapability, the root capability object.

Parameters

capabilityId

string

The root capability identifier to dereference.

Returns

RootCapability

The root capability object.

Example

for did:btcr2:k1q0rnnwf657vuu8trztlczvlmphjgc6q598h79cm6sp7c4fgqh0fkc0vzd9u SHOULD be mutated.

\{
 "@context": [
  "https://w3id.org/zcap/v1",
  "https://w3id.org/security/data-integrity/v2",
  "https://w3id.org/json-ld-patch/v1"
 ],
 "patch": [
  \{
   "op": "add",
   "path": "/service/4",
   "value": \{
      "id": "#linked-domain",
      "type": "LinkedDomains",
      "serviceEndpoint": "https://contact-me.com"
     \}
   \}
 ],
 "proof": \{
   "type": "DataIntegrityProof",
   "cryptosuite": "schnorr-secp256k1-jcs-2025",
   "verificationMethod": "did:btcr2:k1q0rnnwf657vuu8trztlczvlmphjgc6q598h79cm6sp7c4fgqh0fkc0vzd9u#initialKey",
   "invocationTarget": "did:btcr2:k1q0rnnwf657vuu8trztlczvlmphjgc6q598h79cm6sp7c4fgqh0fkc0vzd9u",
   "capability": "urn:zcap:root:did%3Abtcr2%3Ak1q0rnnwf657vuu8trztlczvlmphjgc6q598h79cm6sp7c4fgqh0fkc0vzd9u",
   "capabilityAction": "Write",
   "proofPurpose": "assertionMethod",
   "proofValue": "z381yXYmxU8NudZ4HXY56DfMN6zfD8syvWcRXzT9xD9uYoQToo8QsXD7ahM3gXTzuay5WJbqTswt2BKaGWYn2hHhVFKJLXaDz"
  \}
\}

***

### deriveRootCapability()

> `static` **deriveRootCapability**(`identifier`): [`RootCapability`](../interfaces/RootCapability.md)

Defined in: [packages/method/src/utils/appendix.ts:112](https://github.com/dcdpr/did-btcr2-js/blob/48f9a37f3a84dea95c74c5ee1add0d31eea187e3/packages/method/src/utils/appendix.ts#L112)

Implements [9.4.1 Derive Root Capability from did:btcr2 Identifier](https://dcdpr.github.io/did-btcr2/#derive-root-capability-from-didbtcr2-identifier).

The Derive Root Capability algorithm deterministically generates a ZCAP-LD root capability from a given did:btcr2
identifier. Each root capability is unique to the identifier. This root capability is defined and understood by the
did:btcr2 specification as the root capability to authorize updates to the specific did:btcr2 identifiers DID
document. It takes in a did:btcr2 identifier and returns a rootCapability object. It returns the root capability.

#### Parameters

##### identifier

`string`

The did-btcr2 identifier to derive the root capability from

#### Returns

[`RootCapability`](../interfaces/RootCapability.md)

The root capability object

#### Example

did:btcr2:k1q0rnnwf657vuu8trztlczvlmphjgc6q598h79cm6sp7c4fgqh0fkc0vzd9u

{ "@context": "https://w3id.org/zcap/v1", "id": "urn:zcap:root:did:btcr2:k1q0rnnwf657vuu8trztlczvlmphjgc6q598h79cm6sp7c4fgqh0fkc0vzd9u", "controller": "did:btcr2:k1q0rnnwf657vuu8trztlczvlmphjgc6q598h79cm6sp7c4fgqh0fkc0vzd9u", "invocationTarget": "did:btcr2:k1q0rnnwf657vuu8trztlczvlmphjgc6q598h79cm6sp7c4fgqh0fkc0vzd9u" }

***

### extractDidFragment()

> `static` **extractDidFragment**(`input`): `string` \| `undefined`

Defined in: [packages/method/src/utils/appendix.ts:28](https://github.com/dcdpr/did-btcr2-js/blob/48f9a37f3a84dea95c74c5ee1add0d31eea187e3/packages/method/src/utils/appendix.ts#L28)

Extracts a DID fragment from a given input

#### Parameters

##### input

`unknown`

The input to extract the DID fragment from

#### Returns

`string` \| `undefined`

The extracted DID fragment or undefined if not found

***

### fetchFromCas()

> `static` **fetchFromCas**(`hashBytes`): `Promise`<`string` \| `undefined`>

Defined in: [packages/method/src/utils/appendix.ts:233](https://github.com/dcdpr/did-btcr2-js/blob/48f9a37f3a84dea95c74c5ee1add0d31eea187e3/packages/method/src/utils/appendix.ts#L233)

Implements [9.3. Fetch Content from Addressable Storage](https://dcdpr.github.io/did-btcr2/#fetch-content-from-addressable-storage).

The Fetch Content from Addressable Storage function takes in SHA256 hash of some content, hashBytes, converts these
bytes to a IPFS v1 Content Identifier and attempts to retrieve the identified content from Content Addressable
Storage (CAS). It returns the retrieved content or null.

#### Parameters

##### hashBytes

[`Bytes`](../../api/type-aliases/Bytes.md)

The SHA256 hash of the content to be fetched.

#### Returns

`Promise`<`string` \| `undefined`>

The fetched content or null if not found.

***

### getVerificationMethods()

> `static` **getVerificationMethods**(`didDocument`): [`DidVerificationMethod`](../../api/interfaces/DidVerificationMethod.md)[]

Defined in: [packages/method/src/utils/appendix.ts:75](https://github.com/dcdpr/did-btcr2-js/blob/48f9a37f3a84dea95c74c5ee1add0d31eea187e3/packages/method/src/utils/appendix.ts#L75)

Extracts the verification methods from a given DID Document

#### Parameters

##### didDocument

`DidDocument`

#### Returns

[`DidVerificationMethod`](../../api/interfaces/DidVerificationMethod.md)[]

An array of DidVerificationMethod objects

#### Throws

if the didDocument is not provided

***

### isDidService()

> `static` **isDidService**(`obj`): `obj is DidService`

Defined in: [packages/method/src/utils/appendix.ts:58](https://github.com/dcdpr/did-btcr2-js/blob/48f9a37f3a84dea95c74c5ee1add0d31eea187e3/packages/method/src/utils/appendix.ts#L58)

Validates that the given object is a DidService

#### Parameters

##### obj

`unknown`

The object to validate

#### Returns

`obj is DidService`

A boolean indicating whether the object is a DidService

***

### isDidVerificationMethod()

> `static` **isDidVerificationMethod**(`obj`): `obj is DidVerificationMethod`

Defined in: [packages/method/src/utils/appendix.ts:39](https://github.com/dcdpr/did-btcr2-js/blob/48f9a37f3a84dea95c74c5ee1add0d31eea187e3/packages/method/src/utils/appendix.ts#L39)

Validates that the given object is a DidVerificationMethod

#### Parameters

##### obj

`unknown`

The object to validate

#### Returns

`obj is DidVerificationMethod`

A boolean indicating whether the object is a DidVerificationMethod