HAIP
HAIP, the OpenID4VC High Assurance Interoperability Profile, is an OpenID Foundation specification that constrains the OpenID4VC specs for use where a high level of security and privacy is required — government-issued identity, PID, QEAA — and is the profile the EUDI Wallet ecosystem builds on.
HAIP 1.0 Final (24 December 2025) profiles OpenID4VCI and OpenID4VP 1.0 Final, SD-JWT VC and ISO/IEC 18013-5 (mdoc/mDL) as credential formats, of which an implementation must support at least one, with DCQL as the mandatory query language rather than Presentation Exchange. Trust is anchored in X.509 certificates rather than DIDs, and where a credential is holder-bound a key-binding JWT must be present on presentation.
DIIP describes HAIP as complementary rather than competing: both build on the same OpenID4VCI, OpenID4VP and SD-JWT VC foundation, but HAIP is the higher-assurance, X.509-anchored route the EUDI Wallet and eIDAS 2.0 use for identity credentials such as the PID, while DIIP adds DIDs and W3C VCDM 2.0 for cross-domain ecosystems that do not need that level of assurance.
HAIP is developed within the OpenID Foundation's eKYC and Identity Assurance working group, the same body that maintains OpenID4VCI and OpenID4VP themselves, which keeps the profile in step as those base specifications move from draft to final rather than trailing behind them. Because it is aimed at government-issued credentials, an implementation claiming HAIP conformance is expected to go through the OpenID Foundation's certification program, giving relying parties an independent check rather than a vendor's own claim.
The profile deliberately narrows choice: where OpenID4VCI and OpenID4VP leave several credential formats, query languages and trust models optional, HAIP picks one combination for each, so two HAIP-conformant wallets from different vendors can be relied on to interoperate without additional bilateral testing.
Related terms
Is HAIP mandatory for OpenID4VCI and OpenID4VP implementations?
No. Any implementation is free to build directly against OpenID4VCI and OpenID4VP without following HAIP. What HAIP adds is a fixed, tested set of choices, credential formats, a query language, a trust model, so that two independent implementations following it can be relied on to interoperate without extra bilateral testing. The EUDI Wallet ecosystem requires it precisely because that guarantee matters for government-issued identity.