modelcontextprotocol/python-sdk
Watch
1
0
Fork
You've already forked python-sdk
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Add support for Elicitation (#625)

Browse source 
Co-authored-by: David Soria Parra <davidsp@anthropic.com>
This commit is contained in:
Inna Harper 2025-06-17 11:54:11 +01:00 • committed by GitHub
commit 69e6572d48
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
1 changed files with 643 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

30
src/mcp/client/session.py
View file

@ -22,6 +22,14 @@ class SamplingFnT(Protocol):
) -> types.CreateMessageResult | types.ErrorData: ...
class ElicitationFnT(Protocol):
async def __call__(
self,
context: RequestContext["ClientSession", Any],
params: types.ElicitRequestParams,
) -> types.ElicitResult | types.ErrorData: ...
class ListRootsFnT(Protocol):
async def __call__(
self, context: RequestContext["ClientSession", Any]
@ -58,6 +66,16 @@ async def _default_sampling_callback(
)
async def _default_elicitation_callback(
context: RequestContext["ClientSession", Any],
params: types.ElicitRequestParams,
) -> types.ElicitResult | types.ErrorData:
return types.ErrorData(
code=types.INVALID_REQUEST,
message="Elicitation not supported",
)
async def _default_list_roots_callback(
context: RequestContext["ClientSession", Any],
) -> types.ListRootsResult | types.ErrorData:
@ -91,6 +109,7 @@ class ClientSession(
write_stream: MemoryObjectSendStream[SessionMessage],
read_timeout_seconds: timedelta | None = None,
sampling_callback: SamplingFnT | None = None,
elicitation_callback: ElicitationFnT | None = None,
list_roots_callback: ListRootsFnT | None = None,
logging_callback: LoggingFnT | None = None,
message_handler: MessageHandlerFnT | None = None,
@ -105,12 +124,16 @@ class ClientSession(
)
self._client_info = client_info or DEFAULT_CLIENT_INFO
self._sampling_callback = sampling_callback or _default_sampling_callback
self._elicitation_callback = elicitation_callback or _default_elicitation_callback
self._list_roots_callback = list_roots_callback or _default_list_roots_callback
self._logging_callback = logging_callback or _default_logging_callback
self._message_handler = message_handler or _default_message_handler
async def initialize(self) -> types.InitializeResult:
sampling = types.SamplingCapability() if self._sampling_callback is not _default_sampling_callback else None
elicitation = (
types.ElicitationCapability() if self._elicitation_callback is not _default_elicitation_callback else None
)
roots = (
# TODO: Should this be based on whether we
# _will_ send notifications, or only whether
@ -128,6 +151,7 @@ class ClientSession(
protocolVersion=types.LATEST_PROTOCOL_VERSION,
capabilities=types.ClientCapabilities(
sampling=sampling,
elicitation=elicitation,
experimental=None,
roots=roots,
),
@ -362,6 +386,12 @@ class ClientSession(
client_response = ClientResponse.validate_python(response)
await responder.respond(client_response)
case types.ElicitRequest(params=params):
with responder:
response = await self._elicitation_callback(ctx, params)
client_response = ClientResponse.validate_python(response)
await responder.respond(client_response)
case types.ListRootsRequest():
with responder:
response = await self._list_roots_callback(ctx)