> For the complete documentation index, see [llms.txt](https://docs.empe.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.empe.io/develop/wallet-server/references-and-standards.md).

# References and Standards

The Wallet Server is built on open, interoperable standards so that the credentials it issues and the presentations it verifies work with conformant third-party wallets and verifiers. The specifications below underpin its data models, identifiers, issuance and presentation protocols, credential formats, and authentication.

## Verifiable Credentials & Identifiers

* W3C Verifiable Credentials Data Model: <https://www.w3.org/TR/vc-data-model/>
* W3C Decentralized Identifiers (DID) Core: <https://www.w3.org/TR/did-core/>
* W3C DID Specification Registries (covers `did:web` and `did:key`): <https://www.w3.org/TR/did-spec-registries/>
* The `did:key` Method: <https://w3c-ccg.github.io/did-method-key/>
* The `did:web` Method: <https://w3c-ccg.github.io/did-method-web/>

## Issuance & Presentation Protocols

* OpenID for Verifiable Credential Issuance (OpenID4VCI) — the protocol the service speaks to issue credentials into a holder via the pre-authorized code flow: <https://openid.net/specs/openid-4-verifiable-credential-issuance-1\\_0.html>
* OpenID for Verifiable Presentations (OpenID4VP) — the protocol used to request and verify presentations from a holder: <https://openid.net/specs/openid-4-verifiable-presentations-1\\_0.html>

## Credential Formats

* SD-JWT-based Verifiable Credentials (SD-JWT VC) — the selective-disclosure credential format (identified as `sd-jwt-vc` / `vc+sd-jwt`, and reported as `dc+sd-jwt` in the holder's stored-credential listing): <https://datatracker.ietf.org/doc/draft-ietf-oauth-sd-jwt-vc/>
* Selective Disclosure for JWTs (SD-JWT) — the underlying selective-disclosure mechanism: <https://datatracker.ietf.org/doc/draft-ietf-oauth-selective-disclosure-jwt/>

## Credential Query & Matching

* DIF Presentation Exchange v2 — one of the two ways a verifier describes which credentials it needs: <https://identity.foundation/presentation-exchange/spec/v2.0.0/>
* Digital Credentials Query Language (DCQL) — the alternative credential query language, defined within OpenID4VP: <https://openid.net/specs/openid-4-verifiable-presentations-1\\_0.html#name-dcql-query>

## Authentication & Tokens

* OAuth 2.0 Authorization Framework — the basis for Bearer token authentication on the service's protected endpoints: <https://www.rfc-editor.org/rfc/rfc6749>
* OpenID Connect Core — the identity layer whose JWTs the service validates (`Authorization: Bearer <token>`): <https://openid.net/specs/openid-connect-core-1\\_0.html>
* JSON Web Token (JWT): <https://www.rfc-editor.org/rfc/rfc7519>
* JSON Web Signature (JWS): <https://www.rfc-editor.org/rfc/rfc7515>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.empe.io/develop/wallet-server/references-and-standards.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.