diff --git a/fastmcp_slim/fastmcp/cli/apps_dev.py b/fastmcp_slim/fastmcp/cli/apps_dev.py
index 49cbc771d..2636b9189 100644
--- a/fastmcp_slim/fastmcp/cli/apps_dev.py
+++ b/fastmcp_slim/fastmcp/cli/apps_dev.py
@@ -1217,7 +1217,7 @@ async def _list_tools(mcp_url: str) -> list[dict[str, Any]]:
         return []
 
     try:
-        async with streamable_http_client(mcp_url) as (read, write, _):  # noqa: SIM117
+        async with streamable_http_client(mcp_url) as (read, write):  # noqa: SIM117
             async with ClientSession(read, write) as session:
                 await session.initialize()
                 result = await session.list_tools()
@@ -1232,15 +1232,14 @@ async def _read_mcp_resource(mcp_url: str, uri: str) -> str | None:
     try:
         from mcp import ClientSession
         from mcp.client.streamable_http import streamable_http_client
-        from pydantic import AnyUrl
     except ImportError:
         return None
 
     try:
-        async with streamable_http_client(mcp_url) as (read, write, _):  # noqa: SIM117
+        async with streamable_http_client(mcp_url) as (read, write):  # noqa: SIM117
             async with ClientSession(read, write) as session:
                 await session.initialize()
-                result = await session.read_resource(AnyUrl(uri))
+                result = await session.read_resource(uri)
                 for content in result.contents:
                     text = getattr(content, "text", None)
                     if text:
diff --git a/fastmcp_slim/fastmcp/client/client.py b/fastmcp_slim/fastmcp/client/client.py
index aab21fed7..53f340c8f 100644
--- a/fastmcp_slim/fastmcp/client/client.py
+++ b/fastmcp_slim/fastmcp/client/client.py
@@ -862,17 +862,25 @@ class Client(
         message: str | None = None,
     ) -> None:
         """Send a progress notification."""
-        await self.session.send_progress_notification(
+        # Deprecated upstream in SDK v2 but deliberately kept per compat directive;
+        # removed with the multi-round-trip follow-up.
+        await self.session.send_progress_notification(  # ty: ignore[deprecated]
             progress_token, progress, total, message
         )
 
     async def set_logging_level(self, level: mcp_types.LoggingLevel) -> None:
         """Send a logging/setLevel request."""
-        await self._await_with_session_monitoring(self.session.set_logging_level(level))
+        # Deprecated upstream in SDK v2 but deliberately kept per compat directive;
+        # removed with the multi-round-trip follow-up.
+        await self._await_with_session_monitoring(
+            self.session.set_logging_level(level)  # ty: ignore[deprecated]
+        )
 
     async def send_roots_list_changed(self) -> None:
         """Send a roots/list_changed notification."""
-        await self.session.send_roots_list_changed()
+        # Deprecated upstream in SDK v2 but deliberately kept per compat directive;
+        # removed with the multi-round-trip follow-up.
+        await self.session.send_roots_list_changed()  # ty: ignore[deprecated]
 
     # --- Completion ---
 
diff --git a/fastmcp_slim/fastmcp/client/elicitation.py b/fastmcp_slim/fastmcp/client/elicitation.py
index 155586ae6..2b9ce5db4 100644
--- a/fastmcp_slim/fastmcp/client/elicitation.py
+++ b/fastmcp_slim/fastmcp/client/elicitation.py
@@ -5,7 +5,7 @@ from typing import Any, Generic, TypeAlias
 
 import mcp_types
 from mcp import ClientSession
-from mcp.client.session import ElicitationFnT
+from mcp.client.session import ClientRequestContext, ElicitationFnT
 from mcp_types import ElicitRequestFormParams, ElicitRequestParams
 from mcp_types import ElicitResult as MCPElicitResult
 from pydantic_core import to_jsonable_python
@@ -39,7 +39,7 @@ def create_elicitation_callback(
     elicitation_handler: ElicitationHandler,
 ) -> ElicitationFnT:
     async def _elicitation_handler(
-        context: RequestContext[ClientSession, LifespanContextT],
+        context: ClientRequestContext,
         params: ElicitRequestParams,
     ) -> MCPElicitResult | mcp_types.ErrorData:
         try:
@@ -53,8 +53,14 @@ def create_elicitation_callback(
                 # URL-based elicitation doesn't have a schema
                 response_type = None
 
+            # The public ElicitationHandler alias is typed against the
+            # subscriptable RequestContext shim; the runtime object is the SDK's
+            # ClientRequestContext, passed through opaquely.
             result = await elicitation_handler(
-                params.message, response_type, params, context
+                params.message,
+                response_type,
+                params,
+                context,  # ty: ignore[invalid-argument-type]
             )
             # if the user returns data, we assume they've accepted the elicitation
             if not isinstance(result, ElicitResult):
diff --git a/fastmcp_slim/fastmcp/client/mixins/prompts.py b/fastmcp_slim/fastmcp/client/mixins/prompts.py
index 21f234777..c31a09b46 100644
--- a/fastmcp_slim/fastmcp/client/mixins/prompts.py
+++ b/fastmcp_slim/fastmcp/client/mixins/prompts.py
@@ -164,18 +164,19 @@ class ClientPromptsMixin:
 
             # If meta provided, use send_request for SEP-1686 task support
             if propagated_meta:
-                task_dict = propagated_meta.get("modelcontextprotocol.io/task")
+                # SDK v2: GetPromptRequestParams has no `task` field, so prompt
+                # gets cannot be submitted as background tasks over the wire and
+                # always graceful-degrade to immediate execution (sdk-feedback #3).
                 request = mcp_types.GetPromptRequest(
                     params=mcp_types.GetPromptRequestParams(
                         name=name,
                         arguments=serialized_arguments,
-                        task=mcp_types.TaskMetadata(**task_dict) if task_dict else None,
                         _meta=request_meta,  # type: ignore[unknown-argument]  # pydantic alias
                     )
                 )
                 result = await self._await_with_session_monitoring(
                     self.session.send_request(
-                        request=request,  # type: ignore[arg-type]  # ty:ignore[invalid-argument-type]
+                        request=request,  # type: ignore[arg-type]
                         result_type=mcp_types.GetPromptResult,
                     )
                 )
@@ -301,11 +302,14 @@ class ClientPromptsMixin:
                         "utf-8"
                     )
 
+        # SDK v2: GetPromptRequestParams has no `task` field, so this request
+        # cannot carry task metadata over the wire and the server graceful-
+        # degrades to immediate execution (sdk-feedback #3). `ttl` is retained on
+        # the public API but has no wire representation here.
         request = mcp_types.GetPromptRequest(
             params=mcp_types.GetPromptRequestParams(
                 name=name,
                 arguments=serialized_arguments,
-                task=mcp_types.TaskMetadata(ttl=ttl),
                 _meta=request_meta,  # type: ignore[unknown-argument]  # pydantic alias
             )
         )
@@ -313,7 +317,7 @@ class ClientPromptsMixin:
         # Server returns CreateTaskResult (task accepted) or GetPromptResult (graceful degradation)
         wrapped_result = await self._await_with_session_monitoring(
             self.session.send_request(
-                request=request,  # type: ignore[arg-type]  # ty:ignore[invalid-argument-type]
+                request=request,  # type: ignore[arg-type]
                 result_type=PromptTaskResponseUnion,
             )
         )
diff --git a/fastmcp_slim/fastmcp/client/mixins/resources.py b/fastmcp_slim/fastmcp/client/mixins/resources.py
index 850fd3192..d0c6f50e2 100644
--- a/fastmcp_slim/fastmcp/client/mixins/resources.py
+++ b/fastmcp_slim/fastmcp/client/mixins/resources.py
@@ -232,18 +232,19 @@ class ClientResourcesMixin:
 
             # If meta provided, use send_request for SEP-1686 task support
             if propagated_meta:
-                task_dict = propagated_meta.get("modelcontextprotocol.io/task")
-                # SDK v2: ReadResourceRequestParams.uri is a plain string.
+                # SDK v2: ReadResourceRequestParams has no `task` field, so
+                # resource reads cannot be submitted as background tasks over the
+                # wire and always graceful-degrade to immediate execution
+                # (sdk-feedback #3). The uri is a plain string on the wire.
                 request = mcp_types.ReadResourceRequest(
                     params=mcp_types.ReadResourceRequestParams(
                         uri=uri_str,
-                        task=mcp_types.TaskMetadata(**task_dict) if task_dict else None,
                         _meta=request_meta,  # type: ignore[unknown-argument]  # pydantic alias
                     )
                 )
                 result = await self._await_with_session_monitoring(
                     self.session.send_request(
-                        request=request,  # type: ignore[arg-type]  # ty:ignore[invalid-argument-type]
+                        request=request,  # type: ignore[arg-type]
                         result_type=mcp_types.ReadResourceResult,
                     )
                 )
@@ -363,10 +364,13 @@ class ClientResourcesMixin:
         # are stored under the AnyUrl-normalized form, so normalize to match.
         uri_str = str(AnyUrl(uri)) if isinstance(uri, str) else str(uri)
 
+        # SDK v2: ReadResourceRequestParams has no `task` field, so this request
+        # cannot carry task metadata over the wire and the server graceful-
+        # degrades to immediate execution (sdk-feedback #3). `ttl` is retained on
+        # the public API but has no wire representation here.
         request = mcp_types.ReadResourceRequest(
             params=mcp_types.ReadResourceRequestParams(
                 uri=uri_str,
-                task=mcp_types.TaskMetadata(ttl=ttl),
                 _meta=request_meta,  # type: ignore[unknown-argument]  # pydantic alias
             )
         )
@@ -374,7 +378,7 @@ class ClientResourcesMixin:
         # Server returns CreateTaskResult (task accepted) or ReadResourceResult (graceful degradation)
         wrapped_result = await self._await_with_session_monitoring(
             self.session.send_request(
-                request=request,  # type: ignore[arg-type]  # ty:ignore[invalid-argument-type]
+                request=request,  # type: ignore[arg-type]
                 result_type=ResourceTaskResponseUnion,
             )
         )
diff --git a/fastmcp_slim/fastmcp/client/mixins/task_management.py b/fastmcp_slim/fastmcp/client/mixins/task_management.py
index 2c2e9355e..a011b138a 100644
--- a/fastmcp_slim/fastmcp/client/mixins/task_management.py
+++ b/fastmcp_slim/fastmcp/client/mixins/task_management.py
@@ -67,7 +67,7 @@ class ClientTaskManagementMixin:
         request = GetTaskRequest(params=GetTaskRequestParams(task_id=task_id))
         return await self._await_with_session_monitoring(
             self.session.send_request(
-                request=request,  # type: ignore[arg-type]  # ty:ignore[invalid-argument-type]
+                request=request,  # type: ignore[arg-type]
                 result_type=GetTaskResult,
             )
         )
@@ -94,7 +94,7 @@ class ClientTaskManagementMixin:
         # Return raw result - Task classes handle type-specific parsing
         result = await self._await_with_session_monitoring(
             self.session.send_request(
-                request=request,  # type: ignore[arg-type]  # ty:ignore[invalid-argument-type]
+                request=request,  # type: ignore[arg-type]
                 result_type=_RawTaskPayloadResult,
             )
         )
@@ -132,7 +132,7 @@ class ClientTaskManagementMixin:
         request = ListTasksRequest(params=params)
         server_response = await self._await_with_session_monitoring(
             self.session.send_request(
-                request=request,  # type: ignore[invalid-argument-type]  # ty:ignore[invalid-argument-type]
+                request=request,  # type: ignore[invalid-argument-type]
                 result_type=mcp_types.ListTasksResult,
             )
         )
@@ -172,7 +172,7 @@ class ClientTaskManagementMixin:
         request = CancelTaskRequest(params=CancelTaskRequestParams(task_id=task_id))
         return await self._await_with_session_monitoring(
             self.session.send_request(
-                request=request,  # type: ignore[invalid-argument-type]  # ty:ignore[invalid-argument-type]
+                request=request,  # type: ignore[invalid-argument-type]
                 result_type=mcp_types.CancelTaskResult,
             )
         )
diff --git a/fastmcp_slim/fastmcp/client/roots.py b/fastmcp_slim/fastmcp/client/roots.py
index ee2001920..cb655c1fb 100644
--- a/fastmcp_slim/fastmcp/client/roots.py
+++ b/fastmcp_slim/fastmcp/client/roots.py
@@ -5,7 +5,7 @@ from typing import TypeAlias, cast
 import mcp_types
 import pydantic
 from mcp import ClientSession
-from mcp.client.session import ListRootsFnT
+from mcp.client.session import ClientRequestContext, ListRootsFnT
 
 from fastmcp.client._sdk_context_shim import LifespanContextT, RequestContext
 
@@ -49,7 +49,7 @@ def _create_roots_callback_from_roots(
     roots = convert_roots_list(roots)
 
     async def _roots_callback(
-        context: RequestContext[ClientSession, LifespanContextT],
+        context: ClientRequestContext,
     ) -> mcp_types.ListRootsResult:
         return mcp_types.ListRootsResult(roots=roots)
 
@@ -61,10 +61,13 @@ def _create_roots_callback_from_fn(
     | Callable[[RequestContext[ClientSession, LifespanContextT]], Awaitable[RootsList]],
 ) -> ListRootsFnT:
     async def _roots_callback(
-        context: RequestContext[ClientSession, LifespanContextT],
+        context: ClientRequestContext,
     ) -> mcp_types.ListRootsResult | mcp_types.ErrorData:
         try:
-            roots = fn(context)
+            # The public RootsHandler alias is typed against the subscriptable
+            # RequestContext shim; the runtime object is the SDK's
+            # ClientRequestContext, passed through opaquely.
+            roots = fn(context)  # ty: ignore[invalid-argument-type]
             if inspect.isawaitable(roots):
                 roots = await roots
             return mcp_types.ListRootsResult(
diff --git a/fastmcp_slim/fastmcp/server/auth/oauth_proxy/proxy.py b/fastmcp_slim/fastmcp/server/auth/oauth_proxy/proxy.py
index 33eea92cb..603f8ad0e 100644
--- a/fastmcp_slim/fastmcp/server/auth/oauth_proxy/proxy.py
+++ b/fastmcp_slim/fastmcp/server/auth/oauth_proxy/proxy.py
@@ -947,7 +947,7 @@ class OAuthProxy(OAuthProvider, ConsentMixin):
                     self._resource_url,
                 )
                 raise AuthorizeError(
-                    error="invalid_target",  # type: ignore[arg-type]  # ty:ignore[invalid-argument-type]
+                    error="invalid_target",  # type: ignore[arg-type]
                     error_description="Resource does not match this server",
                 )
 
diff --git a/fastmcp_slim/fastmcp/server/context.py b/fastmcp_slim/fastmcp/server/context.py
index 849ec5de0..65340306c 100644
--- a/fastmcp_slim/fastmcp/server/context.py
+++ b/fastmcp_slim/fastmcp/server/context.py
@@ -803,7 +803,9 @@ class Context:
 
     async def list_roots(self) -> list[Root]:
         """List the roots available to the server, as indicated by the client."""
-        result = await self.session.list_roots()
+        # Deprecated upstream in SDK v2 but deliberately kept per compat directive;
+        # removed with the multi-round-trip follow-up.
+        result = await self.session.list_roots()  # ty: ignore[deprecated]
         return result.roots
 
     async def send_notification(
@@ -1501,7 +1503,9 @@ async def _log_to_server_and_client(
         extra=data.extra,
     )
 
-    await session.send_log_message(
+    # Deprecated upstream in SDK v2 but deliberately kept per compat directive;
+    # removed with the multi-round-trip follow-up.
+    await session.send_log_message(  # ty: ignore[deprecated]
         level=level,
         data=data,
         logger=logger_name,
diff --git a/fastmcp_slim/fastmcp/server/sampling/run.py b/fastmcp_slim/fastmcp/server/sampling/run.py
index 506d445e2..1fba19a5b 100644
--- a/fastmcp_slim/fastmcp/server/sampling/run.py
+++ b/fastmcp_slim/fastmcp/server/sampling/run.py
@@ -230,7 +230,10 @@ async def call_sampling_handler(
             tools=sdk_tools,
             tool_choice=tool_choice,
         ),
-        context.request_context,
+        # SamplingHandler is typed against the SDK's RequestContext placeholder,
+        # but FastMCP hands handlers its own FastMCPRequestContext wrapper at
+        # runtime; the two aren't structurally related in the type system.
+        context.request_context,  # ty: ignore[invalid-argument-type]
     )
 
     if inspect.isawaitable(result):
@@ -555,7 +558,9 @@ async def sample_step_impl(
                     tool_choice=effective_tool_choice,
                 )
             else:
-                response = await context.session.create_message(
+                # Deprecated upstream in SDK v2 but deliberately kept per compat
+                # directive; removed with the multi-round-trip follow-up.
+                response = await context.session.create_message(  # ty: ignore[deprecated]
                     messages=current_messages,
                     system_prompt=system_prompt,
                     temperature=temperature,
diff --git a/fastmcp_slim/fastmcp/server/server.py b/fastmcp_slim/fastmcp/server/server.py
index 2580e729d..bf162d875 100644
--- a/fastmcp_slim/fastmcp/server/server.py
+++ b/fastmcp_slim/fastmcp/server/server.py
@@ -412,7 +412,7 @@ class FastMCP(
         self._started: asyncio.Event = asyncio.Event()
 
         # Generate random ID if no name provided
-        self._mcp_server: LowLevelServer[LifespanResultT, Any] = LowLevelServer[
+        self._mcp_server: LowLevelServer[LifespanResultT] = LowLevelServer[
             LifespanResultT
         ](
             fastmcp=self,
@@ -1260,7 +1260,9 @@ class FastMCP(
                     message=mcp_types.CallToolRequestParams(
                         name=name,
                         arguments=arguments or {},
-                        _meta=_version_request_meta(version),  # type: ignore[unknown-argument]  # pydantic alias
+                        # `_meta` carries the app-level `fastmcp` version key, which the
+                        # reserved-key RequestParamsMeta TypedDict can't express statically.
+                        _meta=_version_request_meta(version),  # type: ignore[unknown-argument]  # ty: ignore[invalid-argument-type]
                     ),
                     source="client",
                     type="request",
@@ -1428,7 +1430,9 @@ class FastMCP(
                 mw_context = MiddlewareContext(
                     message=mcp_types.ReadResourceRequestParams(
                         uri=str(uri),
-                        _meta=_version_request_meta(version),  # type: ignore[unknown-argument]  # pydantic alias
+                        # `_meta` carries the app-level `fastmcp` version key, which the
+                        # reserved-key RequestParamsMeta TypedDict can't express statically.
+                        _meta=_version_request_meta(version),  # type: ignore[unknown-argument]  # ty: ignore[invalid-argument-type]
                     ),
                     source="client",
                     type="request",
@@ -1605,7 +1609,9 @@ class FastMCP(
                     message=mcp_types.GetPromptRequestParams(
                         name=name,
                         arguments=arguments,
-                        _meta=_version_request_meta(version),  # type: ignore[unknown-argument]  # pydantic alias
+                        # `_meta` carries the app-level `fastmcp` version key, which the
+                        # reserved-key RequestParamsMeta TypedDict can't express statically.
+                        _meta=_version_request_meta(version),  # type: ignore[unknown-argument]  # ty: ignore[invalid-argument-type]
                     ),
                     source="client",
                     type="request",