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Credential Parsing

A parser is responsible for recognizing a credential format and transforming it into a common ParsedCredential structure.

The normalized model contains:

  • Credential metadata
  • Issuer information
  • Validity information
  • Signed claims
  • Display metadata and warnings

By exposing a common representation, wallet features can operate independently of the underlying credential format.

Parser Selection​

Parsers are registered with the ParsingEngine.

When a credential is parsed, the engine invokes registered parsers until one successfully recognizes and parses the credential. This allows multiple credential formats to coexist within the same wallet while keeping format-specific logic isolated within each parser implementation.

Unsupported Formats​

A parser should only handle credentials that belong to its supported format.

If a parser determines that a credential is not of the expected format, it should return an UnsupportedFormat parsing error so that the next registered parser can attempt to process the credential.

Credential Display Metadata​

Credential formats often contain only the information required for cryptographic verification.

To support a richer user experience, parsers may resolve and expose display metadata such as:

  • Human-readable credential names
  • Localized labels
  • Claim descriptions
  • Credential images
  • SVG templates and rendering information

This metadata is surfaced through the normalized credential model and can originate from format-specific metadata registries or external resolution services.

Metadata Sources​

Display metadata may originate from different sources depending on the credential format and deployment configuration.

Common sources, prioritized by the order in which they are currently used, include:

  1. External, format-specific configured VC Type Metadata registries (example, wwWallet's VCT Registry for SD-JWT VC Type Metadata (VCT Metadata) for the dc+sd-jwt credential format).
  2. OID4VCI Credential Issuer Metadata for all credential formats.
  3. Application-defined metadata overrides.