diff --git a/packages/core/src/types/spec.types.ts b/packages/core/src/types/spec.types.ts
index a03f21f13..0fe39a2df 100644
--- a/packages/core/src/types/spec.types.ts
+++ b/packages/core/src/types/spec.types.ts
@@ -3,7 +3,7 @@
  *
  * Source: https://github.com/modelcontextprotocol/modelcontextprotocol
  * Pulled from: https://raw.githubusercontent.com/modelcontextprotocol/modelcontextprotocol/main/schema/draft/schema.ts
- * Last updated from commit: 5c25208be86db5033f644a4e0d005e08f699ef3d
+ * Last updated from commit: de6d76fba3078eda957dadb3cec51ca8ab851b5c
  *
  * DO NOT EDIT THIS FILE MANUALLY. Changes will be overwritten by automated updates.
  * To update this file, run: pnpm run fetch:spec-types
@@ -138,6 +138,16 @@ export interface Notification {
     params?: { [key: string]: any };
 }
 
+/**
+ * Indicates the type of a {@link Result} object, allowing the client to
+ * determine how to parse the response.
+ *
+ * complete - the request completed successfully and the result contains the final content.
+ * input_required - the request requires additional input and the result contains an {@link InputRequiredResult} object with instructions for the client to provide additional input before retrying the original request.
+ * @category Common Types
+ */
+export type ResultType = 'complete' | 'input_required';
+
 /**
  * Common result fields.
  *
@@ -145,6 +155,13 @@ export interface Notification {
  */
 export interface Result {
     _meta?: MetaObject;
+    /**
+     * Indicates the type of the result, which allows the client to determine
+     * how to parse the result object.
+     *
+     * @default "complete"
+     */
+    resultType: ResultType;
     [key: string]: unknown;
 }
 
@@ -319,35 +336,86 @@ export interface InternalError extends Error {
     code: typeof INTERNAL_ERROR;
 }
 
-// Implementation-specific JSON-RPC error codes [-32000, -32099]
+/* Empty result */
+/**
+ * A result that indicates success but carries no data.
+ *
+ * @category Common Types
+ */
+export type EmptyResult = Result;
+
+/** @internal */
+export type InputRequest = CreateMessageRequest | ListRootsRequest | ElicitRequest;
+
 /** @internal */
-export const URL_ELICITATION_REQUIRED = -32042;
+export type InputResponse = CreateMessageResult | ListRootsResult | ElicitResult;
 
 /**
- * An error response that indicates that the server requires the client to provide additional information via an elicitation request.
+ * A map of server-initiated requests that the client must fulfill.
+ * Keys are server-assigned identifiers; values are the request objects.
  *
- * @example Authorization required
- * {@includeCode ./examples/URLElicitationRequiredError/authorization-required.json}
+ * @example Elicitation and sampling input requests
+ * {@includeCode ./examples/InputRequests/elicitation-and-sampling-input-requests.json}
  *
- * @internal
+ * @category Multi Round-Trip
  */
-export interface URLElicitationRequiredError extends Omit<JSONRPCErrorResponse, 'error'> {
-    error: Error & {
-        code: typeof URL_ELICITATION_REQUIRED;
-        data: {
-            elicitations: ElicitRequestURLParams[];
-            [key: string]: unknown;
-        };
-    };
+export interface InputRequests {
+    [key: string]: InputRequest;
 }
 
-/* Empty result */
 /**
- * A result that indicates success but carries no data.
+ * A map of client responses to server-initiated requests.
+ * Keys correspond to the keys in the {@link InputRequests} map;
+ * values are the client's result for each request.
  *
- * @category Common Types
+ * @example Elicitation and sampling input responses
+ * {@includeCode ./examples/InputResponses/elicitation-and-sampling-input-responses.json}
+ *
+ * @category Multi Round-Trip
  */
-export type EmptyResult = Result;
+export interface InputResponses {
+    [key: string]: InputResponse;
+}
+
+/**
+ * An InputRequiredResult sent by the server to indicate that additional input is needed
+ * before the request can be completed.
+ *
+ * At least one of `inputRequests` or `requestState` MUST be present.
+ * @example InputRequiredResult with elicitation and sampling input requests and request state
+ * {@includeCode ./examples/InputRequiredResult/input-required-result-with-elicitation-and-sampling-and-request-state.json}
+ *
+ * @example InputRequiredResult with request state only (load shedding)
+ * {@includeCode ./examples/InputRequiredResult/input-required-result-with-request-state-only.json}
+ *
+ * @category Multi Round-Trip
+ */
+export interface InputRequiredResult extends Result {
+    /* Requests issued by the server that must be complete before the
+     * client can retry the original request.
+     */
+    inputRequests?: InputRequests;
+    /* Request state to be passed back to the server when the client
+     * retries the original request.
+     * Note: The client must treat this as an opaque blob; it must not
+     * interpret it in any way.
+     */
+    requestState?: string;
+}
+
+/* Request parameter type that includes input responses and request state.
+ * These parameters may be included in any client-initiated request.
+ */
+export interface InputResponseRequestParams extends RequestParams {
+    /* New field to carry the responses for the server's requests from the
+     * InputRequiredResult message.  For each key in the response's inputRequests
+     * field, the same key must appear here with the associated response.
+     */
+    inputResponses?: InputResponses;
+    /* Request state passed back to the server from the client.
+     */
+    requestState?: string;
+}
 
 /* Cancellation */
 /**
@@ -1015,8 +1083,7 @@ export interface ResourceRequestParams extends RequestParams {
  *
  * @category `resources/read`
  */
-// eslint-disable-next-line @typescript-eslint/no-empty-object-type
-export interface ReadResourceRequestParams extends ResourceRequestParams {}
+export interface ReadResourceRequestParams extends ResourceRequestParams, InputResponseRequestParams {}
 
 /**
  * Sent from the client to the server, to read a specific resource URI.
@@ -1052,7 +1119,7 @@ export interface ReadResourceResult extends Result {
  * @category `resources/read`
  */
 export interface ReadResourceResultResponse extends JSONRPCResultResponse {
-    result: ReadResourceResult;
+    result: ReadResourceResult | InputRequiredResult;
 }
 
 /**
@@ -1336,7 +1403,7 @@ export interface ListPromptsResultResponse extends JSONRPCResultResponse {
  *
  * @category `prompts/get`
  */
-export interface GetPromptRequestParams extends RequestParams {
+export interface GetPromptRequestParams extends InputResponseRequestParams {
     /**
      * The name of the prompt or prompt template.
      */
@@ -1385,7 +1452,7 @@ export interface GetPromptResult extends Result {
  * @category `prompts/get`
  */
 export interface GetPromptResultResponse extends JSONRPCResultResponse {
-    result: GetPromptResult;
+    result: GetPromptResult | InputRequiredResult;
 }
 
 /**
@@ -1580,7 +1647,7 @@ export interface CallToolResult extends Result {
  * @category `tools/call`
  */
 export interface CallToolResultResponse extends JSONRPCResultResponse {
-    result: CallToolResult;
+    result: CallToolResult | InputRequiredResult;
 }
 
 /**
@@ -1594,7 +1661,7 @@ export interface CallToolResultResponse extends JSONRPCResultResponse {
  *
  * @category `tools/call`
  */
-export interface CallToolRequestParams extends TaskAugmentedRequestParams {
+export interface CallToolRequestParams extends InputResponseRequestParams, TaskAugmentedRequestParams {
     /**
      * The name of the tool.
      */
@@ -1908,7 +1975,11 @@ export interface GetTaskResultResponse extends JSONRPCResultResponse {
 }
 
 /**
- * A request to retrieve the result of a completed task.
+ * A request to retrieve the result of a completed task, or to discover
+ * what input is needed for a task in `input_required` status.
+ *
+ * @example Get task payload request
+ * {@includeCode ./examples/GetTaskPayloadRequest/get-task-payload-request.json}
  *
  * @category `tasks/result`
  */
@@ -1927,6 +1998,13 @@ export interface GetTaskPayloadRequest extends JSONRPCRequest {
  * The structure matches the result type of the original request.
  * For example, a {@link CallToolRequest | tools/call} task would return the {@link CallToolResult} structure.
  *
+ * When the task is in `input_required` status, the server MUST return an
+ * {@link InputRequiredResult} containing `inputRequests` that the client must
+ * fulfill via a {@link TaskInputResponseRequest | tasks/input_response} request.
+ *
+ * @example Completed task payload
+ * {@includeCode ./examples/GetTaskPayloadResult/completed-task-payload.json}
+ *
  * @category `tasks/result`
  */
 export interface GetTaskPayloadResult extends Result {
@@ -1935,11 +2013,55 @@ export interface GetTaskPayloadResult extends Result {
 
 /**
  * A successful response for a {@link GetTaskPayloadRequest | tasks/result} request.
+ * May be either a complete result or an {@link InputRequiredResult} indicating
+ * that additional input is needed via {@link TaskInputResponseRequest | tasks/input_response}.
+ *
+ * @example Completed task payload response
+ * {@includeCode ./examples/GetTaskPayloadResultResponse/completed-task-payload-response.json}
+ *
+ * @example Input required task payload response
+ * {@includeCode ./examples/GetTaskPayloadResultResponse/input-required-task-payload-response.json}
  *
  * @category `tasks/result`
  */
 export interface GetTaskPayloadResultResponse extends JSONRPCResultResponse {
-    result: GetTaskPayloadResult;
+    result: GetTaskPayloadResult | InputRequiredResult;
+}
+
+/**
+ * A request from the client to deliver input responses for a task
+ * that is in `input_required` status.
+ *
+ * @example Task input response request
+ * {@includeCode ./examples/TaskInputResponseRequest/task-input-response-request.json}
+ *
+ * @category `tasks/input_response`
+ */
+export interface TaskInputResponseRequest extends JSONRPCRequest {
+    method: 'tasks/input_response';
+    params: TaskInputResponseRequestParams;
+}
+
+/**
+ * Parameters for a `tasks/input_response` request.
+ *
+ * @category `tasks/input_response`
+ */
+export interface TaskInputResponseRequestParams extends RequestParams {
+    /**
+     * The client's responses to the server's input requests from
+     * the {@link InputRequiredResult} returned by {@link GetTaskPayloadRequest | tasks/result}.
+     */
+    inputResponses: InputResponses;
+}
+
+/**
+ * A successful response for a {@link TaskInputResponseRequest | tasks/input_response} request.
+ *
+ * @category `tasks/input_response`
+ */
+export interface TaskInputResponseResultResponse extends JSONRPCResultResponse {
+    result: Result;
 }
 
 /**
@@ -2120,7 +2242,7 @@ export type LoggingLevel = 'debug' | 'info' | 'notice' | 'warning' | 'error' | '
  *
  * @category `sampling/createMessage`
  */
-export interface CreateMessageRequestParams extends TaskAugmentedRequestParams {
+export interface CreateMessageRequestParams {
     messages: SamplingMessage[];
     /**
      * The server's preferences for which model to select. The client MAY ignore these preferences.
@@ -2189,7 +2311,7 @@ export interface ToolChoice {
  *
  * @category `sampling/createMessage`
  */
-export interface CreateMessageRequest extends JSONRPCRequest {
+export interface CreateMessageRequest {
     method: 'sampling/createMessage';
     params: CreateMessageRequestParams;
 }
@@ -2210,7 +2332,7 @@ export interface CreateMessageRequest extends JSONRPCRequest {
  *
  * @category `sampling/createMessage`
  */
-export interface CreateMessageResult extends Result, SamplingMessage {
+export interface CreateMessageResult extends SamplingMessage {
     /**
      * The name of the model that generated the message.
      */
@@ -2230,18 +2352,6 @@ export interface CreateMessageResult extends Result, SamplingMessage {
     stopReason?: 'endTurn' | 'stopSequence' | 'maxTokens' | 'toolUse' | string;
 }
 
-/**
- * A successful response from the client for a {@link CreateMessageRequest | sampling/createMessage} request.
- *
- * @example Sampling result response
- * {@includeCode ./examples/CreateMessageResultResponse/sampling-result-response.json}
- *
- * @category `sampling/createMessage`
- */
-export interface CreateMessageResultResponse extends JSONRPCResultResponse {
-    result: CreateMessageResult;
-}
-
 /**
  * Describes a message issued to or received from an LLM API.
  *
@@ -2695,7 +2805,7 @@ export interface PromptReference extends BaseMetadata {
  *
  * @category `roots/list`
  */
-export interface ListRootsRequest extends JSONRPCRequest {
+export interface ListRootsRequest {
     method: 'roots/list';
     params?: RequestParams;
 }
@@ -2713,22 +2823,10 @@ export interface ListRootsRequest extends JSONRPCRequest {
  *
  * @category `roots/list`
  */
-export interface ListRootsResult extends Result {
+export interface ListRootsResult {
     roots: Root[];
 }
 
-/**
- * A successful response from the client for a {@link ListRootsRequest | roots/list} request.
- *
- * @example List roots result response
- * {@includeCode ./examples/ListRootsResultResponse/list-roots-result-response.json}
- *
- * @category `roots/list`
- */
-export interface ListRootsResultResponse extends JSONRPCResultResponse {
-    result: ListRootsResult;
-}
-
 /**
  * Represents a root directory or file that the server can operate on.
  *
@@ -2782,7 +2880,7 @@ export interface RootsListChangedNotification extends JSONRPCNotification {
  *
  * @category `elicitation/create`
  */
-export interface ElicitRequestFormParams extends TaskAugmentedRequestParams {
+export interface ElicitRequestFormParams {
     /**
      * The elicitation mode.
      */
@@ -2815,7 +2913,7 @@ export interface ElicitRequestFormParams extends TaskAugmentedRequestParams {
  *
  * @category `elicitation/create`
  */
-export interface ElicitRequestURLParams extends TaskAugmentedRequestParams {
+export interface ElicitRequestURLParams {
     /**
      * The elicitation mode.
      */
@@ -2855,7 +2953,7 @@ export type ElicitRequestParams = ElicitRequestFormParams | ElicitRequestURLPara
  *
  * @category `elicitation/create`
  */
-export interface ElicitRequest extends JSONRPCRequest {
+export interface ElicitRequest {
     method: 'elicitation/create';
     params: ElicitRequestParams;
 }
@@ -3107,7 +3205,7 @@ export interface LegacyTitledEnumSchema {
 export type EnumSchema = SingleSelectEnumSchema | MultiSelectEnumSchema | LegacyTitledEnumSchema;
 
 /**
- * The result returned by the client for an {@link ElicitRequest | elicitation/create} request.
+ * The result returned by the client for an {@link ElicitRequest| elicitation/create} request.
  *
  * @example Input single field
  * {@includeCode ./examples/ElicitResult/input-single-field.json}
@@ -3120,7 +3218,7 @@ export type EnumSchema = SingleSelectEnumSchema | MultiSelectEnumSchema | Legacy
  *
  * @category `elicitation/create`
  */
-export interface ElicitResult extends Result {
+export interface ElicitResult {
     /**
      * The user action in response to the elicitation.
      * - `"accept"`: User submitted the form/confirmed the action
@@ -3137,18 +3235,6 @@ export interface ElicitResult extends Result {
     content?: { [key: string]: string | number | boolean | string[] };
 }
 
-/**
- * A successful response from the client for a {@link ElicitRequest | elicitation/create} request.
- *
- * @example Elicitation result response
- * {@includeCode ./examples/ElicitResultResponse/elicitation-result-response.json}
- *
- * @category `elicitation/create`
- */
-export interface ElicitResultResponse extends JSONRPCResultResponse {
-    result: ElicitResult;
-}
-
 /**
  * An optional notification from the server to the client, informing it of a completion of a out-of-band elicitation request.
  *
@@ -3186,7 +3272,8 @@ export type ClientRequest =
     | GetTaskRequest
     | GetTaskPayloadRequest
     | ListTasksRequest
-    | CancelTaskRequest;
+    | CancelTaskRequest
+    | TaskInputResponseRequest;
 
 /** @internal */
 export type ClientNotification =
@@ -3197,27 +3284,11 @@ export type ClientNotification =
     | TaskStatusNotification;
 
 /** @internal */
-export type ClientResult =
-    | EmptyResult
-    | CreateMessageResult
-    | ListRootsResult
-    | ElicitResult
-    | GetTaskResult
-    | GetTaskPayloadResult
-    | ListTasksResult
-    | CancelTaskResult;
+export type ClientResult = EmptyResult | GetTaskResult | GetTaskPayloadResult | ListTasksResult | CancelTaskResult;
 
 /* Server messages */
 /** @internal */
-export type ServerRequest =
-    | PingRequest
-    | CreateMessageRequest
-    | ListRootsRequest
-    | ElicitRequest
-    | GetTaskRequest
-    | GetTaskPayloadRequest
-    | ListTasksRequest
-    | CancelTaskRequest;
+export type ServerRequest = PingRequest | GetTaskRequest | GetTaskPayloadRequest | ListTasksRequest | CancelTaskRequest;
 
 /** @internal */
 export type ServerNotification =
@@ -3247,4 +3318,5 @@ export type ServerResult =
     | GetTaskResult
     | GetTaskPayloadResult
     | ListTasksResult
-    | CancelTaskResult;
+    | CancelTaskResult
+    | InputRequiredResult;