Credential offer
Once all the required workflow components are configured, you can initiate an OID4VCI workflow by creating a Credential offer.
This is achieved by making an API request to a specific MATTR VII endpoint. The request defines the credential configurations that will be used as well as additional request parameters to support the issuance workflow.
MATTR VII responds with an offer URI, which can be shared with intended holders as a QR code, deep-link or wallet notification. This enables the digital wallet to present the offer to the holder and request for consent to initiate the issuance workflow.
MATTR VII exposes two different endpoints to create a credential offer, depending on the authentication flow you are using:
- Authorization Code flow: The returned offer URI will be used by the wallet to redirect the holder to the configured Authentication provider for authentication. Once the holder is authenticated, they are redirected back to the issuance workflow.
- Pre-authorized Code flow: The returned offer URI already includes the pre-authorized code, which is used to authenticate the holder. This code is passed to the wallet and used to request an access token from the issuer’s token endpoint. The access token is then used to request the credential from the issuance endpoint.
The OID4VCI specification supports issuing multiple credentials in a single workflow, so you can reference multiple credential configurations in the same offer. When a multi-format credential offer is created, the generated URI offer is used to issue all the credential formats in a single workflow.