Developed an enhancement for the Philippus/kiota repository, focusing on improving the KiotaBuilder’s handling of OpenAPI schemas with additionalProperties. The work ensured that the AdditionalData property and IAdditionalDataHolder interface are generated even when additionalPropertiesAllowed is set to false, addressing inconsistencies in client code generation. By refining schema processing and code generation logic in C#, the update reduced the need for manual edits and minimized runtime surprises when dealing with dynamic properties in OpenAPI specifications. This targeted feature strengthened the robustness and maintainability of generated SDKs, aligning with best practices for OpenAPI-driven client development and schema fidelity.