Credentials

Retrieve, verify, and present W3C Verifiable Credentials and SD-JWT selective disclosures

Overview

The Credentials service manages W3C Verifiable Credentials and SD-JWT selective disclosures. Retrieve individual credentials, list with filters, verify credential JWTs, and create selective-disclosure presentations.

Get

Retrieve a single Verifiable Credential by its ID.

vc, err := client.Credentials.Get(ctx, "vc_01HXYZ...")
if err != nil {
    log.Fatal(err)
}
fmt.Printf("ID: %s\n", vc.ID)
fmt.Printf("Type: %v\n", vc.Type)
fmt.Printf("Issuer: %s\n", vc.Issuer)
fmt.Printf("Subject: %s\n", vc.Subject)
fmt.Printf("Status: %s\n", vc.Status)

Parameters

Parameter	Type	Required	Description
credentialID	string	Yes	The unique credential identifier.

Response (VerifiableCredential)

Field	Type	Description
ID	string	Unique credential identifier.
Type	[]string	Credential types (always includes "VerifiableCredential").
Issuer	string	DID of the credential issuer.
Subject	string	DID of the credential subject (the holder).
IssuanceDate	string	ISO 8601 timestamp when the credential was issued.
ExpirationDate	*string	ISO 8601 expiration timestamp, or nil if no expiry.
Status	string	Current status: "active", "revoked", or "expired".
JWT	string	The credential in compact JWT format.
Claims	map[string]any	The credential subject claims.

List

List Verifiable Credentials with optional filters.

result, err := client.Credentials.List(ctx, grantex.ListCredentialsParams{
    PrincipalID: grantex.String("user_abc123"),
    Type:        grantex.String("IdentityCredential"),
    Status:      grantex.String("active"),
    Page:        grantex.Int(1),
    PageSize:    grantex.Int(20),
})
if err != nil {
    log.Fatal(err)
}
fmt.Printf("Total: %d\n", result.Total)
for _, vc := range result.Credentials {
    fmt.Printf("  %s: %v\n", vc.ID, vc.Type)
}

Parameters

Parameter	Type	Required	Description
PrincipalID	*string	No	Filter credentials by principal (subject) ID.
Type	*string	No	Filter by credential type (e.g., "IdentityCredential").
Status	*string	No	Filter by status: "active", "revoked", "expired".
Page	*int	No	Page number for pagination (default: 1).
PageSize	*int	No	Results per page (default: 20, max: 100).

Response (ListCredentialsResponse)

Field	Type	Description
Credentials	[]VerifiableCredential	Slice of Verifiable Credential objects.
Total	int	Total number of matching credentials.

Verify

Verify a Verifiable Credential JWT. Checks signature, expiration, revocation status, and issuer trust chain.

result, err := client.Credentials.Verify(ctx, vcJWT)
if err != nil {
    log.Fatal(err)
}
if result.Valid {
    fmt.Printf("Issuer: %s\n", *result.Issuer)
    fmt.Printf("Subject: %s\n", *result.Subject)
    fmt.Printf("Claims: %v\n", result.Claims)
} else {
    fmt.Printf("Invalid: %s\n", *result.Reason)
}

Parameters

Parameter	Type	Required	Description
vcJWT	string	Yes	The Verifiable Credential in compact JWT format.

Response (VerifyCredentialResponse)

Field	Type	Description
Valid	bool	Whether the credential is valid.
Issuer	*string	DID of the issuer (if valid).
Subject	*string	DID of the subject (if valid).
Claims	map[string]any	Credential subject claims (if valid).
ExpiresAt	*string	ISO 8601 expiration timestamp.
Reason	*string	Reason for invalidity: "expired", "revoked", "invalid_signature", "untrusted_issuer".

Present

Create a selective-disclosure presentation from an SD-JWT. Only the specified claims are disclosed.

presentation, err := client.Credentials.Present(ctx, grantex.PresentCredentialParams{
    SDJWT:           "eyJ0eXAiOiJ2YytzZC1qd3QiLC...",
    DisclosedClaims: []string{"name", "email"},
    Audience:        grantex.String("did:web:verifier.example.com"),
    Nonce:           grantex.String("unique-request-nonce"),
})
if err != nil {
    log.Fatal(err)
}
fmt.Printf("Presentation JWT: %s\n", presentation.PresentationJWT)
fmt.Printf("Disclosed: %v\n", presentation.DisclosedClaims)

Parameters

Parameter	Type	Required	Description
SDJWT	string	Yes	The SD-JWT credential to create a presentation from.
DisclosedClaims	[]string	Yes	Claim names to disclose. All others remain hidden.
Audience	*string	No	Intended verifier DID or URL for the holder binding.
Nonce	*string	No	Nonce for replay protection in the holder binding.

Response (PresentCredentialResponse)

Field	Type	Description
PresentationJWT	string	The SD-JWT presentation with only the disclosed claims.
DisclosedClaims	[]string	The claim names that were disclosed.
HolderBinding	string	The key binding JWT proving holder possession.