Add support for Elicitation (#625)

Co-authored-by: David Soria Parra <davidsp@anthropic.com>

src/mcp/server/fastmcp/server.py

@@ -34,6 +34,7 @@ from mcp.server.auth.provider import OAuthAuthorizationServerProvider
 from mcp.server.auth.settings import (
     AuthSettings,
 )
+from mcp.server.elicitation import ElicitationResult, ElicitSchemaModelT, elicit_with_validation
 from mcp.server.fastmcp.exceptions import ResourceError
 from mcp.server.fastmcp.prompts import Prompt, PromptManager
 from mcp.server.fastmcp.resources import FunctionResource, Resource, ResourceManager
@@ -972,6 +973,37 @@ class Context(BaseModel, Generic[ServerSessionT, LifespanContextT, RequestT]):
         assert self._fastmcp is not None, "Context is not available outside of a request"
         return await self._fastmcp.read_resource(uri)
 
+    async def elicit(
+        self,
+        message: str,
+        schema: type[ElicitSchemaModelT],
+    ) -> ElicitationResult[ElicitSchemaModelT]:
+        """Elicit information from the client/user.
+
+        This method can be used to interactively ask for additional information from the
+        client within a tool's execution. The client might display the message to the
+        user and collect a response according to the provided schema. Or in case a
+        client is an agent, it might decide how to handle the elicitation -- either by asking
+        the user or automatically generating a response.
+
+        Args:
+            schema: A Pydantic model class defining the expected response structure, according to the specification,
+                    only primive types are allowed.
+            message: Optional message to present to the user. If not provided, will use
+                    a default message based on the schema
+
+        Returns:
+            An ElicitationResult containing the action taken and the data if accepted
+
+        Note:
+            Check the result.action to determine if the user accepted, declined, or cancelled.
+            The result.data will only be populated if action is "accept" and validation succeeded.
+        """
+
+        return await elicit_with_validation(
+            session=self.request_context.session, message=message, schema=schema, related_request_id=self.request_id
+        )
+
     async def log(
         self,
         level: Literal["debug", "info", "warning", "error"],