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 suppleness for AI purposes, based on Microsoft. The brand new protocol separates roles of the authentication and useful resource servers, enabling simpler integration with present OAuth 2.0 and OpenID join suppliers.
Builders utilizing the up to date SDK additionally acquire entry to MCP’s new elicitation function, which permits servers to request extra data throughout interplay. Elicitation allows extra dynamic and interactive AI experiences, making it simpler to collect needed context earlier than executing duties, Microsoft mentioned. Elicitation is an non-compulsory function. Purchasers can declare help for it as a part of their initialize request. Within the MCP C# SDK, that is carried out by configuring an ElicitationHandler within the McpClientOptions.
Lastly, the 2025-06-18 spec additionally helps structured device output. Previous to this help, device outcomes have been allowed to include structured knowledge however the LLM needed to carry out parsing and interpretation with none steering from the device itself. Now, instruments can return structured content material that’s explicitly outlined. This enables AI fashions to raised perceive and course of the output, based on Microsoft. The MCP C# SDK allows instruments to specify that their output is structured through the UseStructuredContent parameter of the McpServerTool attribute.
