With the MCP C# SDK, which now helps protocol specification model 2025-06-18, builders get a brand new authentication protocol that enhances safety and adaptability for AI purposes, in line with Microsoft. The new protocol separates roles of the authentication and useful resource servers, enabling simpler integration with present OAuth 2.zero and OpenID join suppliers.
Developers utilizing the up to date SDK additionally achieve entry to MCP’s new elicitation characteristic, which permits servers to request further info throughout interplay. Elicitation allows extra dynamic and interactive AI experiences, making it simpler to collect vital context earlier than executing duties, Microsoft mentioned. Elicitation is an optionally available characteristic. Clients can declare help for it as a part of their initialize request. In the MCP C# SDK, that is accomplished by configuring an ElicitationHandler within the McpClientChoices.
Finally, the 2025-06-18 spec additionally helps structured instrument output. Prior to this help, instrument outcomes had been allowed to include structured information however the LLM needed to carry out parsing and interpretation with none steering from the instrument itself. Now, instruments can return structured content material that’s explicitly outlined. This permits AI fashions to raised perceive and course of the output, in line with Microsoft. The MCP C# SDK allows instruments to specify that their output is structured by way of the UseStructuredContent parameter of the McpServerSoftware attribute.
