Credential Service¶

The Credential Service exposes functionality for issuance, proof generation, verification, and revocation of Verifiable Credentials.

Signature Format

The Credential service currently supports BBS+ Signatures , which enable selective disclosure of credential fields during proof generation.

Credentials are signed, and proofs are created, using a key pair unique to the signing / holding wallet. This key pair is created and managed by Trinsic upon account creation.

Issue Credential from Credential Template¶

Issues a credential from a previously-defined credential template.

Sample Request Response

TypeScriptC#PythonGoJava

import { TrinsicService } from "@trinsic/trinsic";

const trinsic = new TrinsicService({ authToken: "<auth token>" });

const request = {
    templateId: "https://schema.trinsic.cloud/default/example-credential",
    include_governance: true,
    valuesJson: JSON.stringify({
        "name": "John Doe",
        "email": "[email protected]"
    })
};
const response = await trinsic.credential().issueFromTemplate(request);

var credentialJson = await trinsic.Credential.IssueFromTemplateAsync(new() {
    TemplateId = templateId,
    ValuesJson = values
});

values = json.dumps({"firstName": "Jane", "lastName": "Doe", "age": "42"})
issue_response = await trinsic_service.credential.issue_from_template(
    request=IssueFromTemplateRequest(
        template_id=template.data.id, values_json=values
    )
)

issueTemplateResponse, err := trinsic.Credential().IssueFromTemplate(context.Background(),
    &credential.IssueFromTemplateRequest{
        ValuesJson: valuesJson,
        TemplateId: templateId,
    })

var valuesMap = new HashMap<String, Object>();
valuesMap.put("firstName", "Jane");
valuesMap.put("lastName", "Doe");
valuesMap.put("age", 42);
var valuesJson = new Gson().toJson(valuesMap);
var issueResponse =
    trinsic
        .credential()
        .issueFromTemplate(
            IssueFromTemplateRequest.newBuilder()
                .setTemplateId(templateId)
                .setValuesJson(valuesJson)
                .build())
        .get();

IssueFromTemplateRequest

Request to create and sign a JSON-LD Verifiable Credential from a template using public key tied to caller

template_id

string

ID of template to use

values_json

string

JSON document string with keys corresponding to the fields of the template referenced by template_id

save_copy

bool

Save a copy of the issued credential to this user's wallet. This copy will only contain the credential data, but not the secret proof value. Issuers may use this data to keep track of the details for revocation status.

expiration_date

string

The ISO8601 expiration UTC date of the credential. This is a reserved field in the VC specification. If specified, the issued credential will contain an expiration date. https://www.w3.org/TR/vc-data-model/#expiration

include_governance

bool

If true, the issued credential will contain an attestation of the issuer's membership in the ecosystem's Trust Registry.

signature_type

SignatureType

The type of signature to use when signing the credential. Defaults to EXPERIMENTAL.

Show enum values

IssueFromTemplateResponse

Response to IssueFromTemplateRequest

document_json

string

Verifiable Credential document, in JSON-LD form, constructed from the specified template and values; signed with public key tied to caller of IssueFromTemplateRequest

Add Trust Registry information to issued credential¶

In order to attach governance information to the credential, issuers must request this explicitly by specifying the parameter include_governance to true in the above request. This will reference the ecosystem's Trust Registry that the issuer is authorized to issue credentials of the designated type (schema).

When this parameter is set to true, the issued credential will contain extended information in the issuer field to assert authorization in the given Trust Registry. The registry identifier will be in the issuer.trustRegistry field. Here's an example of a VC with extended issuer information:

"issuer": {
    "id": "did:key:z5TcEFAQPu7RkrBCMCJDGgVziV",
    "type": "AuthoritativeMember"
    "governanceFramework": "https://acme.org/authorized-issuers",
    "trustRegistry": "urn:egf:acme:92f21b4cb3bc48dd8bb19a872f03afca",
  }

See Trust Registry Service for more information on managing your ecosystem's governance.

Create Credential Offer¶

The purpose of the "Create Offer" endpoint is to initiate interactive issuance and facilitate the issuance of a verifiable credential. This endpoint serves as the starting point for the interactive issuance process, allowing the issuing party to generate an offer to issue a credential to a specific user or entity.

By utilizing the "Create Offer" endpoint, the issuing party can initiate a request for the user's consent to issue a verifiable credential on their behalf. This interactive process ensures that the user actively participates in the credential issuance and has the opportunity to review and provide their consent before the credential is issued.

Furthermore, the "Create Offer" endpoint enables the issuing party to define and configure the holder binding properties of the credential. This means that the issued credential will be bound to the intended holder, making it non-transferable and restricted for use solely by the authorized holder.

Sample Request Response

TypeScript

let createCredentialOfferResponse = await trinsic.credential().createCredentialOffer(
    CreateCredentialOfferRequest.fromPartial({
        templateId: templateId,
        valuesJson: issueResponse.documentJson,
        holderBinding: true,
        includeGovernance: true,
        generateShareUrl: true,
        signatureType: SignatureType.EXPERIMENTAL,
    })
);

CreateCredentialOfferRequest

template_id

string

ID of template to use

values_json

string

JSON document string with keys corresponding to the fields of the template referenced by template_id

holder_binding

optional bool

If true, the credential will be issued with holder binding by specifying the holder DID in the credential subject

include_governance

optional bool

If true, the issued credential will contain an attestation of the issuer's membership in the ecosystem's Trust Registry.

generate_share_url

optional bool

If true, a short URL link will be generated that can be used to share the credential offer with the holder. This link will point to the credential offer in the wallet app.

signature_type

optional SignatureType

The type of signature to use when signing the credential. Defaults to EXPERIMENTAL.

Show enum values

CreateCredentialOfferResponse

document_json

string

The JSON document that contains the credential offer

share_url

string

If requested, a URL that can be used to share the credential offer with the holder. This is a short URL that can be used in a QR code and will redirect the holder to the credential offer using the wallet app.

Accept Credential¶

The purpose of the "Accept Offer" method is for the user to formally accept the offered verifiable credential. It enables the user to provide explicit consent and indicate their willingness to receive and possess the credential. By using this method, the user confirms their agreement to become the rightful holder of the credential.

The "Accept Offer" method is a mandatory step in the issuance process, as it solidifies the user's commitment to acquiring the verifiable credential. During this step, if the issuer requested binding information, the user's wallet will submit a proof of DID ownership bind the credential to the user and make it non-transferable. The verifiable credential is then securely generated and delivered to the user, officially establishing their possession and ownership of the credential.

Sample Request Response

TypeScript

let acceptCredentialResponse = await trinsic.credential().acceptCredential(
    AcceptCredentialRequest.fromPartial({
        documentJson: createCredentialOfferResponse.documentJson,
    })
);

AcceptCredentialRequest

document_json

string

The JSON document that contains the credential offer

item_id

optional string

The ID of the credential offer (Parameter ID inside the JSON document)

AcceptCredentialResponse

item_id

string

The ID of the item in the wallet that contains the issued credential

document_json

string

The JSON document that contains the issued credential. This item is already stored in the wallet.

Reject Credential¶

This endpoint allows users to decline or reject an offered verifiable credential. By utilizing this endpoint, users can explicitly communicate their decision not to accept the credential being offered to them. By offering this option in your application, your platform promotes user empowerment and supports a transparent workflow for the acceptance or rejection of verifiable credentials.

Sample Request Response

TypeScript

let rejectCredentialResponse = await trinsic.credential().rejectCredential(
    RejectCredentialRequest.fromPartial({
        documentJson: createCredentialOfferResponse.documentJson,
    })
);

RejectCredentialRequest

document_json

string

The JSON document that contains the credential offer

item_id

optional string

The ID of the credential offer (Parameter ID inside the JSON document)

RejectCredentialResponse

This message has no fields

Check Revocation Status¶

Checks a credential's revocation status by its credential_status_id.

A credential_status_id can be found in a credential's credentialStatus.id field, if present.

Sample Request Response

Trinsic CLITypeScriptC#PythonGoJava

trinsic vc get-status --credential-status-id <ID>

let checkStatusResponse = await trinsic
    .credential()
    .checkStatus(CheckStatusRequest.fromPartial({}));

var checkResponse = await trinsic.Credential.CheckStatusAsync(new() { CredentialStatusId = "" });

#     check_response = await trinsic_service.credential.check_status(
#         request=CheckStatusRequest(credential_status_id="")
#     )

status, err := trinsic.Credential().CheckStatus(context.Background(), &credential.CheckStatusRequest{CredentialStatusId: ""})

var checkStatusResponse =
    trinsic.credential().checkStatus(CheckStatusRequest.newBuilder().build()).get();

CheckStatusRequest

Request to check a credential's revocation status

credential_status_id

string

Credential Status ID to check. This is not the same as the credential's ID.

CheckStatusResponse

Response to CheckStatusRequest

revoked

bool

The credential's revocation status

Update Revocation Status¶

Updates the revocation status of a credential (revoke or unrevoke).

A credential_status_id can be found in a credential's credentialStatus.id field, if present.

Sample Request Response

Trinsic CLITypeScriptC#PythonGoJava

# Revoke a credential
trinsic vc update-status --revoked --credential-status-id <ID>

# Unrevoke a credential
trinsic vc update-status --unrevoked --credential-status-id <ID>

let updateStatusResponse = await trinsic
    .credential()
    .updateStatus(UpdateStatusRequest.fromPartial({}));

await trinsic.Credential.UpdateStatusAsync(new() { CredentialStatusId = "", Revoked = true });

#     update_response = await trinsic_service.credential.update_status(
#         request=UpdateStatusRequest(credential_status_id="", revoked=True)
#     )

updateStatusResponse, err := trinsic.Credential().UpdateStatus(context.Background(), &credential.UpdateStatusRequest{CredentialStatusId: "", Revoked: true})

trinsic.credential().updateStatus(UpdateStatusRequest.newBuilder().build());

UpdateStatusRequest

Request to update a credential's revocation status

credential_status_id

string

Credential Status ID to update. This is not the same as the credential's ID.

revoked

bool

New revocation status of credential

UpdateStatusResponse

Response to UpdateStatusRequest

This message has no fields

Create Proof¶

Creates and signs a proof for a valid JSON-LD credential, using the BBS+ Signature Suite.

If the credential is stored in a Trinsic cloud wallet, pass its item_id; otherwise, pass the raw JSON-LD credential via document_json.

Selective Disclosure

BBS+ Signatures support the ability to generate a proof for a subset of a credential's fields, instead of every field.

This enables increased user privacy: fields which aren't included in reveal_document_json will not be present in the generated proof.

If reveal_document_json is passed, a proof will be generated for only the fields specified. This is a JSON-LD frame.
Rather than formulating a complete JSON-LD frame, you can instead provide a list of proof attributes to reveal via reveal_template.template_attributes, and the service will construct the JSON-LD proof frame internally
If neither is provided, the entire proof will be returned.

Sample Request Response

Trinsic CLITypeScriptC#PythonGoJava

trinsic vc create-proof --document-id <STRING> --out <OUTPUT_FILE> --reveal-document <JSONLD_FRAME_FILE>

let proof = await trinsic.credential().createProof(
    CreateProofRequest.fromPartial({
        documentJson: issueResponse.documentJson,
        itemId: insertItemResponse.itemId,
    }),
);
let selectiveProof = await trinsic.credential().createProof(
    CreateProofRequest.fromPartial({
        documentJson: issueResponse.documentJson,
        itemId: insertItemResponse.itemId,
        revealTemplate: {
            templateAttributes: ["firstName", "lastName"],
        },
    }),
);

var proof = await trinsic.Credential.CreateProofAsync(new() {
    DocumentJson = credentialJson.DocumentJson,
    RevealDocumentJson = frame.ToString(Formatting.None)
});
var selectiveProof = await trinsic.Credential.CreateProofAsync(new() {
    DocumentJson = credentialJson.DocumentJson,
    RevealTemplate = new() {
        // The other field, not disclosed, is "age"
        TemplateAttributes = { "firstName", "lastName" }
    }
});

proof_response = await trinsic_service.credential.create_proof(
    request=CreateProofRequest(document_json=credential_json)
)
selective_proof_response = await trinsic_service.credential.create_proof(
    request=CreateProofRequest(
        document_json=credential_json,
        reveal_template=RevealTemplateAttributes(template_attributes=["firstName"]),
    )
)

request := &credential.CreateProofRequest{
    Proof: &credential.CreateProofRequest_DocumentJson{
        DocumentJson: credentialJson,
    },
}

proofResponse, err := trinsic.Credential().CreateProof(context.Background(), request)

selectiveRequest := &credential.CreateProofRequest{
    Proof: &credential.CreateProofRequest_DocumentJson{
        DocumentJson: credentialJson,
    },
    Disclosure: &credential.CreateProofRequest_RevealTemplate{RevealTemplate: &credential.RevealTemplateAttributes{TemplateAttributes: []string{"name"}}},
}

selectiveResponse, err2 := trinsic.Credential().CreateProof(context.Background(), selectiveRequest)

var createProofResponse =
    trinsic
        .credential()
        .createProof(
            CreateProofRequest.newBuilder().setDocumentJson(signedCredentialJson).build())
        .get();

var credentialProof = createProofResponse.getProofDocumentJson();

var selectiveProofResponse =
    trinsic
        .credential()
        .createProof(
            CreateProofRequest.newBuilder()
                .setDocumentJson(signedCredentialJson)
                .setRevealTemplate(
                    RevealTemplateAttributes.newBuilder()
                        .addTemplateAttributes("batchNumber")
                        .build())
                .build())
        .get();

var selectiveProof = selectiveProofResponse.getProofDocumentJson();

CreateProofRequest

Request to create a proof for a Verifiable Credential using public key tied to caller. Either item_id, or document_json may be provided, not both.

reveal_document_json

string

A valid JSON-LD frame describing which fields should be revealed in the generated proof. If unspecified, all fields in the document will be revealed

reveal_template

RevealTemplateAttributes

Information about what sections of the document to reveal

Show child attributes

verification_template_id

string

Id of verification template with which to construct the JSON-LD proof document

item_id

string

ID of wallet item stored in a Trinsic cloud wallet

document_json

string

A valid JSON-LD Verifiable Credential document string with an unbound signature. The proof will be derived from this document directly. The document will not be stored in the wallet.

use_verifiable_presentation

bool

Wrap the output in a verifiable presentation. If the credential used in the proof is bound to the holder DID, the output will always use a verifiable presentation and this field will be ignored.

nonce

optional bytes

Nonce value used to derive the proof. If not specified, a random nonce will be generated. This value may be represented in base64 format in the proof model.

CreateProofResponse

Response to CreateProofRequest

proof_document_json

string

Valid JSON-LD proof for the specified credential

Verify Proof¶

Verifies a proof for validity and authenticity. Only supports BBS+ Signatures at present.

Sample Request Response

Trinsic CLITypeScriptC#PythonGoJava

# The JSONLD_FILE refers to the proof document obtained from a CreateProofResponse
trinsic vc issuer verify-proof --proof-document <JSONLD_FILE>

let verifyResponse = await trinsic.credential().verifyProof({
    proofDocumentJson: proof.proofDocumentJson,
});

let selectiveVerifyResponse = await trinsic.credential().verifyProof({
    proofDocumentJson: selectiveProof.proofDocumentJson,
});

var valid = await trinsic.Credential.VerifyProofAsync(new() { ProofDocumentJson = proof.ProofDocumentJson });

verify_result = await trinsic_service.credential.verify_proof(
    request=VerifyProofRequest(proof_document_json=credential_proof)
)
selective_verify_result = await trinsic_service.credential.verify_proof(
    request=VerifyProofRequest(
        proof_document_json=selective_proof_response.proof_document_json
    )
)

verifyResponse, err := trinsic.Credential().VerifyProof(context.Background(), &credential.VerifyProofRequest{
    ProofDocumentJson: proofJson,
})

var verifyProofResponse =
    trinsic
        .credential()
        .verifyProof(
            VerifyProofRequest.newBuilder().setProofDocumentJson(credentialProof).build())
        .get();

boolean isValid = verifyProofResponse.getIsValid();

VerifyProofRequest

Request to verify a proof

proof_document_json

string

JSON-LD proof document string to verify

VerifyProofResponse

Response to VerifyProofRequest

is_valid

bool

Whether all validations in validation_results passed

validation_results

map(string -> ValidationMessage)

Results of each validation check performed, such as schema conformance, revocation status, signature, etc. Detailed results are provided for failed validations.

Show child attributes

Validation Results

The verification process performs a number of validations, each of which may fail independently of the others.

For example, a credential may be expired or revoked, but otherwise perfectly valid.

validation_results contains an entry for each of the following verification steps:

Name	Description
`SignatureVerification`	The cryptographic proof over the entire Verifiable Credential, specifically using BBS+ Proof of Signature
`CredentialStatus`	(if supported by credential) Checks if credential has been revoked
`SchemaConformance`	Ensures credential conforms with its schema. It is possible to issue a credential omitting a required field (as captured in the credential template). If your use case allows this kind of omission, you can ignore this validation entry.
`TrustRegistryMembership`	(if relevant) Verifies that credential issuer is an authorized member of the credential's governing Trust Registry
`IssuerIsSigner`	Document `issuer` is same DID as document signer. If false, it is not safe to assume that the claimed `issuer` actually issued the credential.

Exchange Credentials¶

Send via Email¶

Sends a credential to a user via email.

The specified email address must be tied to an existing account in the same ecosystem.

Sample Request Response

Trinsic CLITypeScriptC#PythonGoJava

trinsic vc send --email <EMAIL_ADDRESS> --item <FILE>

await trinsic.credential().send(SendRequest.fromPartial({
    documentJson: issueResponse.documentJson,
    email: "<EMAIL>",
    sendNotification: true,
}));

var sendResponse = await trinsic.Credential.SendAsync(new() {
    Email = "<EMAIL>",
    DocumentJson = issueResponse.DocumentJson,
    SendNotification = true,
    });

send_response = await trinsic_service.credential.send(
    request=SendRequest(
        document_json=credential_json, email="[email protected]"
    )
)

sendResponse, err := trinsic.Credential().Send(context.Background(), &credential.SendRequest{
    DeliveryMethod: &credential.SendRequest_Email{
        Email: "[email protected]",
    },
    DocumentJson: credentialJson,
})

trinsic
    .credential()
    .send(
        SendRequest.newBuilder()
            .setDocumentJson(signedCredentialJson)
            .setEmail(recipientEmail)
            .build());

SendRequest

Request to send a document to another user's wallet

email

string

Email address of user to whom you'll send the item

wallet_id

string

Wallet ID of the recipient within the ecosystem

did_uri

string

DID URI of the recipient

phone_number

string

SMS of user to whom you'll send the item

send_notification

optional bool

Send email notification that credential has been sent to a wallet

document_json

string

JSON document to send to recipient

SendResponse

Response to SendRequest

This message has no fields

Alternative Exchange Protocols

Credentials may only be sent to a wallet via email address or with the InsertItem call.

There are a number of ongoing industry efforts to standardize exchange protocols, such as:

We aim to provide support for these methods as they mature.