Credentials

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

Overview

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

Access the credentials client via client.credentials.

Get

Retrieve a single Verifiable Credential by its ID.

from grantex import Grantex

with Grantex(api_key="gx_live_...") as client:
    vc = client.credentials.get("vc_01HXYZ...")

    print(f"ID: {vc.id}")
    print(f"Type: {vc.type}")
    print(f"Issuer: {vc.issuer}")
    print(f"Subject: {vc.subject}")
    print(f"Status: {vc.status}")
    print(f"Issued: {vc.issuance_date}")

Parameters

Parameter	Type	Required	Description
credential_id	str	Yes	The unique credential identifier.

VerifiableCredential

Field	Type	Description
id	str	Unique credential identifier.
type	tuple[str, ...]	Credential types (always includes 'VerifiableCredential').
issuer	str	DID of the credential issuer.
subject	str	DID of the credential subject (the holder).
issuance_date	str	ISO 8601 timestamp when the credential was issued.
expiration_date	str | None	ISO 8601 expiration timestamp, or None if no expiry.
status	str	Current status: 'active', 'revoked', or 'expired'.
jwt	str	The credential in compact JWT format.
claims	dict[str, Any]	The credential subject claims.

List

List Verifiable Credentials with optional filters.

from grantex import Grantex, ListCredentialsParams

with Grantex(api_key="gx_live_...") as client:
    result = client.credentials.list(ListCredentialsParams(
        principal_id="user_abc123",
        type="IdentityCredential",
        status="active",
        page=1,
        page_size=20,
    ))

    print(f"Total: {len(result.credentials)}")
    for vc in result.credentials:
        print(f"  {vc.id}: {vc.type}")

ListCredentialsParams

Parameter	Type	Required	Description
principal_id	str | None	No	Filter credentials by principal (subject) ID.
type	str | None	No	Filter by credential type (e.g., 'IdentityCredential').
status	str | None	No	Filter by status: 'active', 'revoked', 'expired'.
page	int | None	No	Page number for pagination (default: 1).
page_size	int | None	No	Results per page (default: 20, max: 100).

ListCredentialsResponse

Field	Type	Description
credentials	list[VerifiableCredential]	List 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.

from grantex import Grantex

with Grantex(api_key="gx_live_...") as client:
    result = client.credentials.verify("eyJhbGciOiJFUzI1NiIs...")

    if result.valid:
        print(f"Issuer: {result.issuer}")
        print(f"Subject: {result.subject}")
        print(f"Claims: {result.claims}")
        print(f"Expires at: {result.expires_at}")
    else:
        print(f"Invalid: {result.reason}")

Parameters

Parameter	Type	Required	Description
vc_jwt	str	Yes	The Verifiable Credential in compact JWT format.

VerifyCredentialResponse

Field	Type	Description
valid	bool	Whether the credential is valid.
issuer	str | None	DID of the issuer (present when valid).
subject	str | None	DID of the subject (present when valid).
claims	dict[str, Any] | None	Credential subject claims (present when valid).
expires_at	str | None	ISO 8601 expiration timestamp.
reason	str | None	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.

from grantex import Grantex, PresentCredentialParams

with Grantex(api_key="gx_live_...") as client:
    presentation = client.credentials.present(PresentCredentialParams(
        sd_jwt="eyJ0eXAiOiJ2YytzZC1qd3QiLC...",
        disclosed_claims=["name", "email"],
        audience="did:web:verifier.example.com",
        nonce="unique-request-nonce",
    ))

    print(f"Presentation JWT: {presentation.presentation_jwt}")
    print(f"Disclosed: {presentation.disclosed_claims}")
    print(f"Holder binding: {presentation.holder_binding}")

PresentCredentialParams

Parameter	Type	Required	Description
sd_jwt	str	Yes	The SD-JWT credential to create a presentation from.
disclosed_claims	list[str]	Yes	Claim names to disclose. All others remain hidden.
audience	str | None	No	Intended verifier DID or URL for the holder binding.
nonce	str | None	No	Nonce for replay protection in the holder binding.

PresentCredentialResponse

Field	Type	Description
presentation_jwt	str	The SD-JWT presentation containing only the disclosed claims.
disclosed_claims	list[str]	The claim names that were disclosed.
holder_binding	str	The key binding JWT proving holder possession.

Example: Credential Lifecycle

from grantex import Grantex, ListCredentialsParams, PresentCredentialParams

with Grantex(api_key="gx_live_...") as client:
    # List active credentials for a user
    result = client.credentials.list(ListCredentialsParams(
        principal_id="user_abc123",
        status="active",
    ))

    # Verify a specific credential
    vc = result.credentials[0]
    verification = client.credentials.verify(vc.jwt)
    if not verification.valid:
        raise ValueError(f"Credential invalid: {verification.reason}")

    # Create a selective-disclosure presentation
    presentation = client.credentials.present(PresentCredentialParams(
        sd_jwt=vc.jwt,
        disclosed_claims=["name", "email"],
        audience="did:web:verifier.example.com",
        nonce="unique-request-nonce",
    ))

    # Send presentation.presentation_jwt to the verifier
    print(f"Presentation ready: {len(presentation.disclosed_claims)} claims disclosed")