Gjermund Stensrud enhanced token-based security in the DuendeSoftware/foss repository by implementing support for additional custom claims in DPoP proof payloads. He designed an end-to-end solution in C# that retrieves extra claims within the AccessTokenHandler and propagates them to the DPoPProofService, which then integrates these claims into the generated proof token. To streamline this process, he introduced a new extension method and expanded both unit and integration test coverage to ensure correct claim inclusion. Gjermund’s work leveraged his expertise in API development, OAuth, and security, resulting in a robust feature that improves the flexibility of DPoP token generation.