SEP-2575：使 MCP 无状态

export interface RequestMetaObject extends MetaObject {
  progressToken?: ProgressToken;
+ /**
+  * The MCP Protocol Version being used for this request.
+  */
+ "io.modelcontextprotocol/protocolVersion": string;
  // Additional per-request fields (clientInfo, clientCapabilities, logLevel)
  // are introduced in the Per-Request Client Capabilities section below.
}

export const UNSUPPORTED_PROTOCOL_VERSION = -32022;

export interface UnsupportedProtocolVersionError extends Omit<
  JSONRPCErrorResponse,
  "error"
> {
  error: Error & {
    code: typeof UNSUPPORTED_PROTOCOL_VERSION;
    data: {
      /**
       * An array of protocol version strings that the server supports.
       */
      supported: string[];
      /**
       * The protocol version that was requested by the client.
       */
      requested: string;
    };
  };
}

export interface DiscoverRequest extends Request {
  method: "server/discover";
  params?: {};
}

export interface DiscoverResult extends Result {
  /**
   * A list of MCP Protocol Version strings that this server supports.
   * The client should choose a version from this list for use in
   * subsequent requests.
   */
  supportedVersions: string[];

  /**
   * An object detailing the capabilities of the server.
   */
  capabilities: ServerCapabilities;

  /**
   * Information about the server software implementation.
   */
  serverInfo: Implementation;

  /**
   * Natural language instructions describing how to use the server and
   * its features. This can be used by clients to improve an LLM's
   * understanding of available tools (e.g., by including it in a system prompt).
   */
  instructions?: string;
}

export interface RequestMetaObject extends MetaObject {
  progressToken?: ProgressToken;
  /**
   * The MCP Protocol Version being used for this request.
   */
  "io.modelcontextprotocol/protocolVersion": string;
  /**
   * Identifies the client software.
   */
  "io.modelcontextprotocol/clientInfo": Implementation;
  /**
   * Capabilities of the client for this specific request.
   */
  "io.modelcontextprotocol/clientCapabilities": ClientCapabilities;
  /**
   * The desired log level for this request.
   */
  "io.modelcontextprotocol/logLevel"?: LoggingLevel;
}

export const MISSING_REQUIRED_CLIENT_CAPABILITY = -32021;

export interface MissingRequiredClientCapabilityError extends Omit<
  JSONRPCErrorResponse,
  "error"
> {
  error: Error & {
    code: typeof MISSING_REQUIRED_CLIENT_CAPABILITY;
    data: {
      /**
       * The capabilities the server requires from the client
       * to process this request.
       */
      requiredCapabilities: ClientCapabilities;
    };
  };
}

export interface SubscriptionsListenRequest extends Request {
  method: "subscriptions/listen";
  params: {
    _meta: {
      "io.modelcontextprotocol/protocolVersion": string;
      "io.modelcontextprotocol/clientInfo": Implementation;
      "io.modelcontextprotocol/clientCapabilities": ClientCapabilities;
      // ... other meta fields
    };

    /**
     * The notifications the client wants to receive on this stream.
     * Each notification type is opt-in; the server **MUST NOT** send
     * notification types the client has not explicitly requested here.
     */
    notifications: {
      /**
       * If true, receive notifications/tools/list_changed.
       */
      toolsListChanged?: boolean;

      /**
       * If true, receive notifications/prompts/list_changed.
       */
      promptsListChanged?: boolean;

      /**
       * If true, receive notifications/resources/list_changed.
       */
      resourcesListChanged?: boolean;

      /**
       * Subscribe to notifications/resources/updated for specific
       * resource URIs. Replaces the resources/subscribe RPC.
       */
      resourceSubscriptions?: string[];
    };
  };
}

export interface SubscriptionsAcknowledgedNotification extends Notification {
  method: "notifications/subscriptions/acknowledged";
  params: {
    /**
     * The notification subscriptions the server has agreed to honor.
     * Only includes notification types the server actually supports.
     * If the client requested an unsupported notification type
     * (e.g., promptsListChanged when the server has no prompts),
     * it is omitted from this set.
     */
    notifications: {
      toolsListChanged?: boolean;
      promptsListChanged?: boolean;
      resourcesListChanged?: boolean;
      resourceSubscriptions?: string[];
    };
  };
}

{
  "jsonrpc": "2.0",
  "method": "notifications/tools/list_changed",
  "params": {
    "_meta": {
      "io.modelcontextprotocol/subscriptionId": "<original listen request id>"
    }
  }
}