12.3. Wallet Metadata Retrieval Flow

There are Digital Credential flows that require retrieving Wallet information before interacting with the Wallet itself. For example, to enable the Wallet Solution selection option during a Credential Offer flow or a Presentation flow. To do so, the third parties offering the Credential Offer (e.g., Authentic Source, Registry, Catalogue) and the Relying Parties consult the IT-Wallet System Register, in particular the Federation Registry, via the Trust Anchor's endpoints.

First, using the Immediate Subordinate Listing endpoint they obtain the list of all subordinates of the Trust Anchor identified by their entity_id. To obtain only the Wallet Provider entity_id, a query parameter entity_type set with wallet_provider MAY be used. If the responder does not support this feature, it MUST use the HTTP status code 400 and the content type application/json, with the error code unsupported_parameter.

Then, given the entity_id, they fetch the corresponding Entity Configuration for each Wallet Provider using the federation metadata endpoint (GET .well-known/openid-federation) and obtain the Wallet Solution metadata (see Wallet Solution Metadata). More details on the use of the Trust Anchor's endpoints are provided in The Infrastructure of Trust.

Inside the metadata, the third parties offering the Credential Offer and the Relying Parties retrieve the necessary information for the Selection Page, i.e. the logo and name in full of the Wallet Solutions. More details on the design of the Selection Page are provided in User Experience Design.