refactor: split RequestContext between server and client (#1987)

.github/actions/conformance/client.py

@@ -187,7 +187,7 @@ async def run_sse_retry(server_url: str) -> None:
 
 
 async def default_elicitation_callback(
-    context: RequestContext[ClientSession, Any],  # noqa: ARG001
+    context: RequestContext[ClientSession],
     params: types.ElicitRequestParams,
 ) -> types.ElicitResult | types.ErrorData:
     """Accept elicitation and apply defaults from the schema (SEP-1034)."""

README.v2.md

@@ -229,7 +229,6 @@ from contextlib import asynccontextmanager
 from dataclasses import dataclass
 
 from mcp.server.mcpserver import Context, MCPServer
-from mcp.server.session import ServerSession
 
 
 # Mock database class for example
@@ -275,7 +274,7 @@ mcp = MCPServer("My App", lifespan=app_lifespan)
 
 # Access type-safe lifespan context in tools
 @mcp.tool()
-def query_db(ctx: Context[ServerSession, AppContext]) -> str:
+def query_db(ctx: Context[AppContext]) -> str:
     """Tool that uses initialized resources."""
     db = ctx.request_context.lifespan_context.db
     return db.query()
@@ -2135,7 +2134,7 @@ server_params = StdioServerParameters(
 
 # Optional: create a sampling callback
 async def handle_sampling_message(
-    context: RequestContext[ClientSession, None], params: types.CreateMessageRequestParams
+    context: RequestContext[ClientSession], params: types.CreateMessageRequestParams
 ) -> types.CreateMessageResult:
     print(f"Sampling request: {params.messages}")
     return types.CreateMessageResult(

docs/migration.md

@@ -371,6 +371,50 @@ async def handle_tool(name: str, arguments: dict) -> list[TextContent]:
         await ctx.session.send_progress_notification(ctx.meta["progress_token"], 0.5, 100)
 ```
 
+### `RequestContext` and `ProgressContext` type parameters simplified
+
+The `RequestContext` class has been split to separate shared fields from server-specific fields. The shared `RequestContext` now only takes 1 type parameter (the session type) instead of 3.
+
+**`RequestContext` changes:**
+
+- Type parameters reduced from `RequestContext[SessionT, LifespanContextT, RequestT]` to `RequestContext[SessionT]`
+- Server-specific fields (`lifespan_context`, `experimental`, `request`, `close_sse_stream`, `close_standalone_sse_stream`) moved to new `ServerRequestContext` class in `mcp.server.context`
+
+**`ProgressContext` changes:**
+
+- Type parameters reduced from `ProgressContext[SendRequestT, SendNotificationT, SendResultT, ReceiveRequestT, ReceiveNotificationT]` to `ProgressContext[SessionT]`
+
+**Before (v1):**
+
+```python
+from mcp.shared.context import RequestContext, LifespanContextT, RequestT
+from mcp.shared.progress import ProgressContext
+
+# RequestContext with 3 type parameters
+ctx: RequestContext[ClientSession, LifespanContextT, RequestT]
+
+# ProgressContext with 5 type parameters
+progress_ctx: ProgressContext[SendRequestT, SendNotificationT, SendResultT, ReceiveRequestT, ReceiveNotificationT]
+```
+
+**After (v2):**
+
+```python
+from mcp.shared.context import RequestContext
+from mcp.shared.progress import ProgressContext
+
+# RequestContext with 1 type parameter
+ctx: RequestContext[ClientSession]
+
+# ProgressContext with 1 type parameter
+progress_ctx: ProgressContext[ClientSession]
+
+# For server-specific context with lifespan and request types
+from mcp.server.context import ServerRequestContext, LifespanContextT, RequestT
+
+server_ctx: ServerRequestContext[LifespanContextT, RequestT]
+```
+
 ### Resource URI type changed from `AnyUrl` to `str`
 
 The `uri` field on resource-related types now uses `str` instead of Pydantic's `AnyUrl`. This aligns with the [MCP specification schema](https://github.com/modelcontextprotocol/modelcontextprotocol/blob/main/schema/draft/schema.ts) which defines URIs as plain strings (`uri: string`) without strict URL validation. This change allows relative paths like `users/me` that were previously rejected.

examples/clients/simple-task-interactive-client/mcp_simple_task_interactive_client/main.py

@@ -7,7 +7,6 @@ This example demonstrates the spec-compliant polling pattern:
 """
 
 import asyncio
-from typing import Any
 
 import click
 from mcp import ClientSession
@@ -24,7 +23,7 @@ from mcp.types import (
 
 
 async def elicitation_callback(
-    context: RequestContext[ClientSession, Any],
+    context: RequestContext[ClientSession],
     params: ElicitRequestParams,
 ) -> ElicitResult:
     """Handle elicitation requests from the server."""
@@ -39,7 +38,7 @@ async def elicitation_callback(
 
 
 async def sampling_callback(
-    context: RequestContext[ClientSession, Any],
+    context: RequestContext[ClientSession],
     params: CreateMessageRequestParams,
 ) -> CreateMessageResult:
     """Handle sampling requests from the server."""

examples/snippets/clients/stdio_client.py

@@ -19,7 +19,7 @@ server_params = StdioServerParameters(
 
 # Optional: create a sampling callback
 async def handle_sampling_message(
-    context: RequestContext[ClientSession, None], params: types.CreateMessageRequestParams
+    context: RequestContext[ClientSession], params: types.CreateMessageRequestParams
 ) -> types.CreateMessageResult:
     print(f"Sampling request: {params.messages}")
     return types.CreateMessageResult(

examples/snippets/clients/url_elicitation_client.py

@@ -38,7 +38,7 @@ from mcp.types import URL_ELICITATION_REQUIRED
 
 
 async def handle_elicitation(
-    context: RequestContext[ClientSession, Any],
+    context: RequestContext[ClientSession],
     params: types.ElicitRequestParams,
 ) -> types.ElicitResult | types.ErrorData:
     """Handle elicitation requests from the server.

examples/snippets/servers/lifespan_example.py

@@ -5,7 +5,6 @@ from contextlib import asynccontextmanager
 from dataclasses import dataclass
 
 from mcp.server.mcpserver import Context, MCPServer
-from mcp.server.session import ServerSession
 
 
 # Mock database class for example
@@ -51,7 +50,7 @@ mcp = MCPServer("My App", lifespan=app_lifespan)
 
 # Access type-safe lifespan context in tools
 @mcp.tool()
-def query_db(ctx: Context[ServerSession, AppContext]) -> str:
+def query_db(ctx: Context[AppContext]) -> str:
     """Tool that uses initialized resources."""
     db = ctx.request_context.lifespan_context.db
     return db.query()

src/mcp/client/experimental/task_handlers.py

@@ -11,8 +11,10 @@ Use cases:
 - Server polls client's task status via tasks/get, tasks/result, etc.
 """
 
+from __future__ import annotations
+
 from dataclasses import dataclass, field
-from typing import TYPE_CHECKING, Any, Protocol
+from typing import TYPE_CHECKING, Protocol
 
 from pydantic import TypeAdapter
 
@@ -32,7 +34,7 @@ class GetTaskHandlerFnT(Protocol):
 
     async def __call__(
         self,
-        context: RequestContext["ClientSession", Any],
+        context: RequestContext[ClientSession],
         params: types.GetTaskRequestParams,
     ) -> types.GetTaskResult | types.ErrorData: ...  # pragma: no branch
 
@@ -45,7 +47,7 @@ class GetTaskResultHandlerFnT(Protocol):
 
     async def __call__(
         self,
-        context: RequestContext["ClientSession", Any],
+        context: RequestContext[ClientSession],
         params: types.GetTaskPayloadRequestParams,
     ) -> types.GetTaskPayloadResult | types.ErrorData: ...  # pragma: no branch
 
@@ -58,7 +60,7 @@ class ListTasksHandlerFnT(Protocol):
 
     async def __call__(
         self,
-        context: RequestContext["ClientSession", Any],
+        context: RequestContext[ClientSession],
         params: types.PaginatedRequestParams | None,
     ) -> types.ListTasksResult | types.ErrorData: ...  # pragma: no branch
 
@@ -71,7 +73,7 @@ class CancelTaskHandlerFnT(Protocol):
 
     async def __call__(
         self,
-        context: RequestContext["ClientSession", Any],
+        context: RequestContext[ClientSession],
         params: types.CancelTaskRequestParams,
     ) -> types.CancelTaskResult | types.ErrorData: ...  # pragma: no branch
 
@@ -88,7 +90,7 @@ class TaskAugmentedSamplingFnT(Protocol):
 
     async def __call__(
         self,
-        context: RequestContext["ClientSession", Any],
+        context: RequestContext[ClientSession],
         params: types.CreateMessageRequestParams,
         task_metadata: types.TaskMetadata,
     ) -> types.CreateTaskResult | types.ErrorData: ...  # pragma: no branch
@@ -106,14 +108,14 @@ class TaskAugmentedElicitationFnT(Protocol):
 
     async def __call__(
         self,
-        context: RequestContext["ClientSession", Any],
+        context: RequestContext[ClientSession],
         params: types.ElicitRequestParams,
         task_metadata: types.TaskMetadata,
     ) -> types.CreateTaskResult | types.ErrorData: ...  # pragma: no branch
 
 
 async def default_get_task_handler(
-    context: RequestContext["ClientSession", Any],
+    context: RequestContext[ClientSession],
     params: types.GetTaskRequestParams,
 ) -> types.GetTaskResult | types.ErrorData:
     return types.ErrorData(
@@ -123,7 +125,7 @@ async def default_get_task_handler(
 
 
 async def default_get_task_result_handler(
-    context: RequestContext["ClientSession", Any],
+    context: RequestContext[ClientSession],
     params: types.GetTaskPayloadRequestParams,
 ) -> types.GetTaskPayloadResult | types.ErrorData:
     return types.ErrorData(
@@ -133,7 +135,7 @@ async def default_get_task_result_handler(
 
 
 async def default_list_tasks_handler(
-    context: RequestContext["ClientSession", Any],
+    context: RequestContext[ClientSession],
     params: types.PaginatedRequestParams | None,
 ) -> types.ListTasksResult | types.ErrorData:
     return types.ErrorData(
@@ -143,7 +145,7 @@ async def default_list_tasks_handler(
 
 
 async def default_cancel_task_handler(
-    context: RequestContext["ClientSession", Any],
+    context: RequestContext[ClientSession],
     params: types.CancelTaskRequestParams,
 ) -> types.CancelTaskResult | types.ErrorData:
     return types.ErrorData(
@@ -153,7 +155,7 @@ async def default_cancel_task_handler(
 
 
 async def default_task_augmented_sampling(
-    context: RequestContext["ClientSession", Any],
+    context: RequestContext[ClientSession],
     params: types.CreateMessageRequestParams,
     task_metadata: types.TaskMetadata,
 ) -> types.CreateTaskResult | types.ErrorData:
@@ -164,7 +166,7 @@ async def default_task_augmented_sampling(
 
 
 async def default_task_augmented_elicitation(
-    context: RequestContext["ClientSession", Any],
+    context: RequestContext[ClientSession],
     params: types.ElicitRequestParams,
     task_metadata: types.TaskMetadata,
 ) -> types.CreateTaskResult | types.ErrorData:
@@ -248,7 +250,7 @@ class ExperimentalTaskHandlers:
 
     async def handle_request(
         self,
-        ctx: RequestContext["ClientSession", Any],
+        ctx: RequestContext[ClientSession],
         responder: RequestResponder[types.ServerRequest, types.ClientResult],
     ) -> None:
         """Handle a task-related request from the server.

src/mcp/client/session.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import logging
 from typing import Any, Protocol
 
@@ -22,7 +24,7 @@ logger = logging.getLogger("client")
 class SamplingFnT(Protocol):
     async def __call__(
         self,
-        context: RequestContext["ClientSession", Any],
+        context: RequestContext[ClientSession],
         params: types.CreateMessageRequestParams,
     ) -> types.CreateMessageResult | types.CreateMessageResultWithTools | types.ErrorData: ...  # pragma: no branch
 
@@ -30,22 +32,19 @@ class SamplingFnT(Protocol):
 class ElicitationFnT(Protocol):
     async def __call__(
         self,
-        context: RequestContext["ClientSession", Any],
+        context: RequestContext[ClientSession],
         params: types.ElicitRequestParams,
     ) -> types.ElicitResult | types.ErrorData: ...  # pragma: no branch
 
 
 class ListRootsFnT(Protocol):
     async def __call__(
-        self, context: RequestContext["ClientSession", Any]
+        self, context: RequestContext[ClientSession]
     ) -> types.ListRootsResult | types.ErrorData: ...  # pragma: no branch
 
 
 class LoggingFnT(Protocol):
-    async def __call__(
-        self,
-        params: types.LoggingMessageNotificationParams,
-    ) -> None: ...  # pragma: no branch
+    async def __call__(self, params: types.LoggingMessageNotificationParams) -> None: ...  # pragma: no branch
 
 
 class MessageHandlerFnT(Protocol):
@@ -62,7 +61,7 @@ async def _default_message_handler(
 
 
 async def _default_sampling_callback(
-    context: RequestContext["ClientSession", Any],
+    context: RequestContext[ClientSession],
     params: types.CreateMessageRequestParams,
 ) -> types.CreateMessageResult | types.CreateMessageResultWithTools | types.ErrorData:
     return types.ErrorData(
@@ -72,7 +71,7 @@ async def _default_sampling_callback(
 
 
 async def _default_elicitation_callback(
-    context: RequestContext["ClientSession", Any],
+    context: RequestContext[ClientSession],
     params: types.ElicitRequestParams,
 ) -> types.ElicitResult | types.ErrorData:
     return types.ErrorData(  # pragma: no cover
@@ -82,7 +81,7 @@ async def _default_elicitation_callback(
 
 
 async def _default_list_roots_callback(
-    context: RequestContext["ClientSession", Any],
+    context: RequestContext[ClientSession],
 ) -> types.ListRootsResult | types.ErrorData:
     return types.ErrorData(
         code=types.INVALID_REQUEST,
@@ -153,10 +152,7 @@ class ClientSession(
             else None
         )
         elicitation = (
-            types.ElicitationCapability(
-                form=types.FormElicitationCapability(),
-                url=types.UrlElicitationCapability(),
-            )
+            types.ElicitationCapability(form=types.FormElicitationCapability(), url=types.UrlElicitationCapability())
             if self._elicitation_callback is not _default_elicitation_callback
             else None
         )
@@ -414,12 +410,7 @@ class ClientSession(
         await self.send_notification(types.RootsListChangedNotification())
 
     async def _received_request(self, responder: RequestResponder[types.ServerRequest, types.ClientResult]) -> None:
-        ctx = RequestContext[ClientSession, Any](
-            request_id=responder.request_id,
-            meta=responder.request_meta,
-            session=self,
-            lifespan_context=None,
-        )
+        ctx = RequestContext[ClientSession](request_id=responder.request_id, meta=responder.request_meta, session=self)
 
         # Delegate to experimental task handler if applicable
         if self._task_handlers.handles_request(responder.request):

src/mcp/server/context.py

@@ -0,0 +1,23 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Any, Generic
+
+from typing_extensions import TypeVar
+
+from mcp.server.experimental.request_context import Experimental
+from mcp.server.session import ServerSession
+from mcp.shared.context import RequestContext
+from mcp.shared.message import CloseSSEStreamCallback
+
+LifespanContextT = TypeVar("LifespanContextT")
+RequestT = TypeVar("RequestT", default=Any)
+
+
+@dataclass(kw_only=True)
+class ServerRequestContext(RequestContext[ServerSession], Generic[LifespanContextT, RequestT]):
+    lifespan_context: LifespanContextT
+    experimental: Experimental
+    request: RequestT | None = None
+    close_sse_stream: CloseSSEStreamCallback | None = None
+    close_standalone_sse_stream: CloseSSEStreamCallback | None = None

src/mcp/server/experimental/request_context.py

@@ -57,10 +57,7 @@ class Experimental:
         return self._client_capabilities.tasks is not None
 
     def validate_task_mode(
-        self,
-        tool_task_mode: TaskExecutionMode | None,
-        *,
-        raise_error: bool = True,
+        self, tool_task_mode: TaskExecutionMode | None, *, raise_error: bool = True
     ) -> ErrorData | None:
         """Validate that the request is compatible with the tool's task execution mode.
 
@@ -95,12 +92,7 @@ class Experimental:
 
         return error
 
-    def validate_for_tool(
-        self,
-        tool: Tool,
-        *,
-        raise_error: bool = True,
-    ) -> ErrorData | None:
+    def validate_for_tool(self, tool: Tool, *, raise_error: bool = True) -> ErrorData | None:
         """Validate that the request is compatible with the given tool.
 
         Convenience wrapper around validate_task_mode that extracts the mode from a Tool.

src/mcp/server/lowlevel/server.py

@@ -91,6 +91,7 @@ from mcp.server.auth.middleware.bearer_auth import BearerAuthBackend, RequireAut
 from mcp.server.auth.provider import OAuthAuthorizationServerProvider, TokenVerifier
 from mcp.server.auth.routes import build_resource_metadata_url, create_auth_routes, create_protected_resource_routes
 from mcp.server.auth.settings import AuthSettings
+from mcp.server.context import ServerRequestContext
 from mcp.server.experimental.request_context import Experimental
 from mcp.server.lowlevel.experimental import ExperimentalHandlers
 from mcp.server.lowlevel.func_inspection import create_call_wrapper
@@ -100,7 +101,6 @@ from mcp.server.session import ServerSession
 from mcp.server.streamable_http import EventStore
 from mcp.server.streamable_http_manager import StreamableHTTPASGIApp, StreamableHTTPSessionManager
 from mcp.server.transport_security import TransportSecuritySettings
-from mcp.shared.context import RequestContext
 from mcp.shared.exceptions import MCPError, UrlElicitationRequiredError
 from mcp.shared.message import ServerMessageMetadata, SessionMessage
 from mcp.shared.session import RequestResponder
@@ -117,16 +117,11 @@ UnstructuredContent: TypeAlias = Iterable[types.ContentBlock]
 CombinationContent: TypeAlias = tuple[UnstructuredContent, StructuredContent]
 
 # This will be properly typed in each Server instance's context
-request_ctx: contextvars.ContextVar[RequestContext[ServerSession, Any, Any]] = contextvars.ContextVar("request_ctx")
+request_ctx: contextvars.ContextVar[ServerRequestContext[Any, Any]] = contextvars.ContextVar("request_ctx")
 
 
 class NotificationOptions:
-    def __init__(
-        self,
-        prompts_changed: bool = False,
-        resources_changed: bool = False,
-        tools_changed: bool = False,
-    ):
+    def __init__(self, prompts_changed: bool = False, resources_changed: bool = False, tools_changed: bool = False):
         self.prompts_changed = prompts_changed
         self.resources_changed = resources_changed
         self.tools_changed = tools_changed
@@ -253,9 +248,7 @@ class Server(Generic[LifespanResultT, RequestT]):
         return capabilities
 
     @property
-    def request_context(
-        self,
-    ) -> RequestContext[ServerSession, LifespanResultT, RequestT]:
+    def request_context(self) -> ServerRequestContext[LifespanResultT, RequestT]:
         """If called outside of a request context, this will raise a LookupError."""
         return request_ctx.get()
 
@@ -762,12 +755,12 @@ class Server(Generic[LifespanResultT, RequestT]):
                 if hasattr(req, "params") and req.params is not None:
                     task_metadata = getattr(req.params, "task", None)
                 token = request_ctx.set(
-                    RequestContext(
-                        message.request_id,
-                        message.request_meta,
-                        session,
-                        lifespan_context,
-                        Experimental(
+                    ServerRequestContext(
+                        request_id=message.request_id,
+                        meta=message.request_meta,
+                        session=session,
+                        lifespan_context=lifespan_context,
+                        experimental=Experimental(
                             task_metadata=task_metadata,
                             _client_capabilities=client_capabilities,
                             _session=session,

src/mcp/server/mcpserver/prompts/base.py

@@ -14,9 +14,8 @@ from mcp.server.mcpserver.utilities.func_metadata import func_metadata
 from mcp.types import ContentBlock, Icon, TextContent
 
 if TYPE_CHECKING:
+    from mcp.server.context import LifespanContextT, RequestT
     from mcp.server.mcpserver.server import Context
-    from mcp.server.session import ServerSessionT
-    from mcp.shared.context import LifespanContextT, RequestT
 
 
 class Message(BaseModel):
@@ -137,7 +136,7 @@ class Prompt(BaseModel):
     async def render(
         self,
         arguments: dict[str, Any] | None = None,
-        context: Context[ServerSessionT, LifespanContextT, RequestT] | None = None,
+        context: Context[LifespanContextT, RequestT] | None = None,
     ) -> list[Message]:
         """Render the prompt with arguments."""
         # Validate required arguments

src/mcp/server/mcpserver/prompts/manager.py

@@ -8,9 +8,8 @@ from mcp.server.mcpserver.prompts.base import Message, Prompt
 from mcp.server.mcpserver.utilities.logging import get_logger
 
 if TYPE_CHECKING:
+    from mcp.server.context import LifespanContextT, RequestT
     from mcp.server.mcpserver.server import Context
-    from mcp.server.session import ServerSessionT
-    from mcp.shared.context import LifespanContextT, RequestT
 
 logger = get_logger(__name__)
 
@@ -50,7 +49,7 @@ class PromptManager:
         self,
         name: str,
         arguments: dict[str, Any] | None = None,
-        context: Context[ServerSessionT, LifespanContextT, RequestT] | None = None,
+        context: Context[LifespanContextT, RequestT] | None = None,
     ) -> list[Message]:
         """Render a prompt by name with arguments."""
         prompt = self.get_prompt(name)

src/mcp/server/mcpserver/resources/resource_manager.py

@@ -13,9 +13,8 @@ from mcp.server.mcpserver.utilities.logging import get_logger
 from mcp.types import Annotations, Icon
 
 if TYPE_CHECKING:
+    from mcp.server.context import LifespanContextT, RequestT
     from mcp.server.mcpserver.server import Context
-    from mcp.server.session import ServerSessionT
-    from mcp.shared.context import LifespanContextT, RequestT
 
 logger = get_logger(__name__)
 
@@ -82,7 +81,7 @@ class ResourceManager:
         return template
 
     async def get_resource(
-        self, uri: AnyUrl | str, context: Context[ServerSessionT, LifespanContextT, RequestT] | None = None
+        self, uri: AnyUrl | str, context: Context[LifespanContextT, RequestT] | None = None
     ) -> Resource:
         """Get resource by URI, checking concrete resources first, then templates."""
         uri_str = str(uri)

src/mcp/server/mcpserver/resources/templates.py

@@ -16,9 +16,8 @@ from mcp.server.mcpserver.utilities.func_metadata import func_metadata
 from mcp.types import Annotations, Icon
 
 if TYPE_CHECKING:
+    from mcp.server.context import LifespanContextT, RequestT
     from mcp.server.mcpserver.server import Context
-    from mcp.server.session import ServerSessionT
-    from mcp.shared.context import LifespanContextT, RequestT
 
 
 class ResourceTemplate(BaseModel):
@@ -100,7 +99,7 @@ class ResourceTemplate(BaseModel):
         self,
         uri: str,
         params: dict[str, Any],
-        context: Context[ServerSessionT, LifespanContextT, RequestT] | None = None,
+        context: Context[LifespanContextT, RequestT] | None = None,
     ) -> Resource:
         """Create a resource from the template with the given parameters."""
         try:

src/mcp/server/mcpserver/server.py

@@ -25,6 +25,7 @@ from mcp.server.auth.middleware.auth_context import AuthContextMiddleware
 from mcp.server.auth.middleware.bearer_auth import BearerAuthBackend, RequireAuthMiddleware
 from mcp.server.auth.provider import OAuthAuthorizationServerProvider, ProviderTokenVerifier, TokenVerifier
 from mcp.server.auth.settings import AuthSettings
+from mcp.server.context import LifespanContextT, RequestT, ServerRequestContext
 from mcp.server.elicitation import ElicitationResult, ElicitSchemaModelT, UrlElicitationResult, elicit_with_validation
 from mcp.server.elicitation import elicit_url as _elicit_url
 from mcp.server.lowlevel.helper_types import ReadResourceContents
@@ -36,13 +37,11 @@ from mcp.server.mcpserver.resources import FunctionResource, Resource, ResourceM
 from mcp.server.mcpserver.tools import Tool, ToolManager
 from mcp.server.mcpserver.utilities.context_injection import find_context_parameter
 from mcp.server.mcpserver.utilities.logging import configure_logging, get_logger
-from mcp.server.session import ServerSession, ServerSessionT
 from mcp.server.sse import SseServerTransport
 from mcp.server.stdio import stdio_server
 from mcp.server.streamable_http import EventStore
 from mcp.server.streamable_http_manager import StreamableHTTPSessionManager
 from mcp.server.transport_security import TransportSecuritySettings
-from mcp.shared.context import LifespanContextT, RequestContext, RequestT
 from mcp.types import Annotations, ContentBlock, GetPromptResult, Icon, ToolAnnotations
 from mcp.types import Prompt as MCPPrompt
 from mcp.types import PromptArgument as MCPPromptArgument
@@ -294,7 +293,7 @@ class MCPServer(Generic[LifespanResultT]):
             for info in tools
         ]
 
-    def get_context(self) -> Context[ServerSession, LifespanResultT, Request]:
+    def get_context(self) -> Context[LifespanResultT, Request]:
         """Returns a Context object. Note that the context will only be valid
         during a request; outside a request, most methods will error.
         """
@@ -972,7 +971,7 @@ class MCPServer(Generic[LifespanResultT]):
             raise ValueError(str(e))
 
 
-class Context(BaseModel, Generic[ServerSessionT, LifespanContextT, RequestT]):
+class Context(BaseModel, Generic[LifespanContextT, RequestT]):
     """Context object providing access to MCP capabilities.
 
     This provides a cleaner interface to MCP's RequestContext functionality.
@@ -1006,14 +1005,15 @@ class Context(BaseModel, Generic[ServerSessionT, LifespanContextT, RequestT]):
     The context is optional - tools that don't need it can omit the parameter.
     """
 
-    _request_context: RequestContext[ServerSessionT, LifespanContextT, RequestT] | None
+    _request_context: ServerRequestContext[LifespanContextT, RequestT] | None
     _mcp_server: MCPServer | None
 
     def __init__(
         self,
         *,
-        request_context: (RequestContext[ServerSessionT, LifespanContextT, RequestT] | None) = None,
+        request_context: ServerRequestContext[LifespanContextT, RequestT] | None = None,
         mcp_server: MCPServer | None = None,
+        # TODO(Marcelo): We should drop this kwargs parameter.
         **kwargs: Any,
     ):
         super().__init__(**kwargs)
@@ -1028,9 +1028,7 @@ class Context(BaseModel, Generic[ServerSessionT, LifespanContextT, RequestT]):
         return self._mcp_server  # pragma: no cover
 
     @property
-    def request_context(
-        self,
-    ) -> RequestContext[ServerSessionT, LifespanContextT, RequestT]:
+    def request_context(self) -> ServerRequestContext[LifespanContextT, RequestT]:
         """Access to the underlying request context."""
         if self._request_context is None:  # pragma: no cover
             raise ValueError("Context is not available outside of a request")

src/mcp/server/mcpserver/tools/base.py

@@ -16,9 +16,8 @@ from mcp.shared.tool_name_validation import validate_and_warn_tool_name
 from mcp.types import Icon, ToolAnnotations
 
 if TYPE_CHECKING:
+    from mcp.server.context import LifespanContextT, RequestT
     from mcp.server.mcpserver.server import Context
-    from mcp.server.session import ServerSessionT
-    from mcp.shared.context import LifespanContextT, RequestT
 
 
 class Tool(BaseModel):
@@ -93,7 +92,7 @@ class Tool(BaseModel):
     async def run(
         self,
         arguments: dict[str, Any],
-        context: Context[ServerSessionT, LifespanContextT, RequestT] | None = None,
+        context: Context[LifespanContextT, RequestT] | None = None,
         convert_result: bool = False,
     ) -> Any:
         """Run the tool with arguments."""

src/mcp/server/mcpserver/tools/tool_manager.py

@@ -6,12 +6,11 @@ from typing import TYPE_CHECKING, Any
 from mcp.server.mcpserver.exceptions import ToolError
 from mcp.server.mcpserver.tools.base import Tool
 from mcp.server.mcpserver.utilities.logging import get_logger
-from mcp.shared.context import LifespanContextT, RequestT
 from mcp.types import Icon, ToolAnnotations
 
 if TYPE_CHECKING:
+    from mcp.server.context import LifespanContextT, RequestT
     from mcp.server.mcpserver.server import Context
-    from mcp.server.session import ServerSessionT
 
 logger = get_logger(__name__)
 
@@ -82,7 +81,7 @@ class ToolManager:
         self,
         name: str,
         arguments: dict[str, Any],
-        context: Context[ServerSessionT, LifespanContextT, RequestT] | None = None,
+        context: Context[LifespanContextT, RequestT] | None = None,
         convert_result: bool = False,
     ) -> Any:
         """Call a tool by name with arguments."""

src/mcp/shared/context.py

@@ -1,30 +1,20 @@
 """Request context for MCP handlers."""
 
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from typing import Any, Generic
 
 from typing_extensions import TypeVar
 
-from mcp.shared.message import CloseSSEStreamCallback
 from mcp.shared.session import BaseSession
 from mcp.types import RequestId, RequestParamsMeta
 
 SessionT = TypeVar("SessionT", bound=BaseSession[Any, Any, Any, Any, Any])
-LifespanContextT = TypeVar("LifespanContextT")
-RequestT = TypeVar("RequestT", default=Any)
 
 
-@dataclass
-class RequestContext(Generic[SessionT, LifespanContextT, RequestT]):
+@dataclass(kw_only=True)
+class RequestContext(Generic[SessionT]):
+    """Common context for handling incoming requests."""
+
     request_id: RequestId
     meta: RequestParamsMeta | None
     session: SessionT
-    lifespan_context: LifespanContextT
-    # NOTE: This is typed as Any to avoid circular imports. The actual type is
-    # mcp.server.experimental.request_context.Experimental, but importing it here
-    # triggers mcp.server.__init__ -> mcpserver -> tools -> back to this module.
-    # The Server sets this to an Experimental instance at runtime.
-    experimental: Any = field(default=None)
-    request: RequestT | None = None
-    close_sse_stream: CloseSSEStreamCallback | None = None
-    close_standalone_sse_stream: CloseSSEStreamCallback | None = None