978 pages for system.

Architecture Model Context Protocol · in the page specification/2025-11-25/architecture/index …ation The Model Context Protocol uses a capability-based negotiation system where clients and servers explicitly declare their supported features during initialization. Capabilities determine which p… Lifecycle Model Context Protocol · in the page specification/2025-11-25/basic/lifecycle …scription | | - | - | - | | Client | `roots` | Ability to provide filesystem [roots](https://modelcontextprotocol.io/specification/2025-11-25/client/roots.md) | | Client | `sampling` | Support for LLM… Key Changes Model Context Protocol · in the page specification/2025-11-25/changelog …protocol/modelcontextprotocol/issues/1302)). 4. Establish SDK tiering system with clear requirements for feature support and maintenance commitments ([SEP-1730](https://github.com/modelcontextprotocol… Roots Model Context Protocol · in the page specification/2025-11-25/client/roots …Protocol (MCP) provides a standardized way for clients to expose filesystem "roots" to servers. Roots define the boundaries of where servers can operate within the filesystem, allowing them to unders… Sampling Model Context Protocol · in the page specification/2025-11-25/client/sampling …"intelligencePriority": 0.8, "speedPriority": 0.5 }, "systemPrompt": "You are a helpful assistant.", "maxTokens": 100 } } ``` **Response:** ```json theme={null} { "jsonrpc":… Specification Model Context Protocol · in the page specification/2025-11-25/index …nformation with language models * Expose tools and capabilities to AI systems * Build composable integrations and workflows The protocol uses [JSON-RPC](https://www.jsonrpc.org/) 2.0 messages to esta… Schema Reference Model Context Protocol · in the page specification/2025-11-25/schema …hint" to the model. For example, this information MAY be added to the system prompt.</p> </div></section> </div> <div class="type"> ### `ClientCapabilities` <div class="tsd-signature"><span clas… Resources Model Context Protocol · in the page specification/2025-11-25/server/resources …rnet. ### file:// Used to identify resources that behave like a filesystem. However, the resources do not need to map to an actual physical filesystem. MCP servers **MAY** identify file:// resource… Tools Model Context Protocol · in the page specification/2025-11-25/server/tools …ked by language models. Tools enable models to interact with external systems, such as querying databases, calling APIs, or performing computations. Each tool is uniquely identified by a name and incl… Logging Model Context Protocol · in the page specification/2025-11-25/server/utilities/logging …conditions | Operation failures | | critical | Critical conditions | System component failures | | alert | Action must be taken immediately | Data corruption detected | | emergency | System is unusab… Architecture Model Context Protocol · in the page specification/2026-07-28/architecture/index …ation The Model Context Protocol uses a capability-based negotiation system where clients and servers declare their supported features on each request. Clients include their capabilities in `_meta.io… Multi Round-Trip Requests Model Context Protocol · in the page specification/2026-07-28/basic/patterns/mrtr …What is the capital of France?" } } ], "systemPrompt": "You are a helpful assistant.", "maxTokens": 100 } } } ``` #### InputResponses An [`InputResponses`](… stdio Model Context Protocol · in the page specification/2026-07-28/basic/transports/stdio …ting the process using the mechanism appropriate for the operating system. On POSIX systems, forced termination typically escalates from [`SIGTERM`][sigterm] to `SIGKILL`. On Windows, where POSIX… Roots Model Context Protocol · in the page specification/2026-07-28/client/roots …Protocol (MCP) provides a standardized way for clients to expose filesystem "roots" to servers. Roots inform servers about the directories and files the client considers relevant, so that servers can… Sampling Model Context Protocol · in the page specification/2026-07-28/client/sampling …: 0.8, "speedPriority": 0.5 }, "temperature": 0.1, "systemPrompt": "You are a helpful assistant.", "includeContext": "thisServer", "maxTokens": 100 } } ``` **Client result… Specification Model Context Protocol · in the page specification/2026-07-28/index …nformation with language models * Expose tools and capabilities to AI systems * Build composable integrations and workflows The protocol uses [JSON-RPC](https://www.jsonrpc.org/) 2.0 messages to esta… Resources Model Context Protocol · in the page specification/2026-07-28/server/resources …rnet. ### file:// Used to identify resources that behave like a filesystem. However, the resources do not need to map to an actual physical filesystem. MCP servers **MAY** identify file:// resource… Tools Model Context Protocol · in the page specification/2026-07-28/server/tools …ked by language models. Tools enable models to interact with external systems, such as querying databases, calling APIs, or performing computations. Each tool is uniquely identified by a name and incl… Logging Model Context Protocol · in the page specification/2026-07-28/server/utilities/logging …conditions | Operation failures | | critical | Critical conditions | System component failures | | alert | Action must be taken immediately | Data corruption detected | | emergency | System is unusab… Architecture Model Context Protocol · in the page specification/draft/architecture/index …ation The Model Context Protocol uses a capability-based negotiation system where clients and servers declare their supported features on each request. Clients include their capabilities in `_meta.io… Multi Round-Trip Requests Model Context Protocol · in the page specification/draft/basic/patterns/mrtr …What is the capital of France?" } } ], "systemPrompt": "You are a helpful assistant.", "maxTokens": 100 } } } ``` #### InputResponses An [`InputResponses`](… stdio Model Context Protocol · in the page specification/draft/basic/transports/stdio …ting the process using the mechanism appropriate for the operating system. On POSIX systems, forced termination typically escalates from [`SIGTERM`][sigterm] to `SIGKILL`. On Windows, where POSIX… Roots Model Context Protocol · in the page specification/draft/client/roots …Protocol (MCP) provides a standardized way for clients to expose filesystem "roots" to servers. Roots inform servers about the directories and files the client considers relevant, so that servers can… Sampling Model Context Protocol · in the page specification/draft/client/sampling …: 0.8, "speedPriority": 0.5 }, "temperature": 0.1, "systemPrompt": "You are a helpful assistant.", "includeContext": "thisServer", "maxTokens": 100 } } ``` **Client result… Specification Model Context Protocol · in the page specification/draft/index …nformation with language models * Expose tools and capabilities to AI systems * Build composable integrations and workflows The protocol uses [JSON-RPC](https://www.jsonrpc.org/) 2.0 messages to esta… Resources Model Context Protocol · in the page specification/draft/server/resources …rnet. ### file:// Used to identify resources that behave like a filesystem. However, the resources do not need to map to an actual physical filesystem. MCP servers **MAY** identify file:// resource… Tools Model Context Protocol · in the page specification/draft/server/tools …ked by language models. Tools enable models to interact with external systems, such as querying databases, calling APIs, or performing computations. Each tool is uniquely identified by a name and incl… Logging Model Context Protocol · in the page specification/draft/server/utilities/logging …conditions | Operation failures | | critical | Critical conditions | System component failures | | alert | Action must be taken immediately | Data corruption detected | | emergency | System is unusab…