json-rpc

import { z, ZodTypeAny } from "zod";

export const LATEST_PROTOCOL_VERSION = "2025-03-26"; export const SUPPORTED_PROTOCOL_VERSIONS = [ LATEST_PROTOCOL_VERSION, "2024-11-05", "2024-10-07", ];

/* JSON-RPC types */ export const JSONRPC_VERSION = "2.0";

/**

• A progress token, used to associate progress notifications with the original request. */ export const ProgressTokenSchema = z.union([z.string(), z.number().int()]);

/**

• An opaque token used to represent a cursor for pagination. */ export const CursorSchema = z.string();

const RequestMetaSchema = z .object({ /** * If specified, the caller is requesting out-of-band progress notifications for this request (as represented by notifications/progress). The value of this parameter is an opaque token that will be attached to any subsequent notifications. The receiver is not obligated to provide these notifications. */ progressToken: z.optional(ProgressTokenSchema), }) .passthrough();

const BaseRequestParamsSchema = z .object({ _meta: z.optional(RequestMetaSchema), }) .passthrough();

export const RequestSchema = z.object({ method: z.string(), params: z.optional(BaseRequestParamsSchema), });

const BaseNotificationParamsSchema = z .object({ /** * This parameter name is reserved by MCP to allow clients and servers to attach additional metadata to their notifications. */ _meta: z.optional(z.object({}).passthrough()), }) .passthrough();

export const NotificationSchema = z.object({ method: z.string(), params: z.optional(BaseNotificationParamsSchema), });

export const ResultSchema = z .object({ /** * This result property is reserved by the protocol to allow clients and servers to attach additional metadata to their responses. */ _meta: z.optional(z.object({}).passthrough()), }) .passthrough();

/**

• A uniquely identifying ID for a request in JSON-RPC. */ export const RequestIdSchema = z.union([z.string(), z.number().int()]);

/**

• A request that expects a response. */ export const JSONRPCRequestSchema = z .object({ jsonrpc: z.literal(JSONRPC_VERSION), id: RequestIdSchema, }) .merge(RequestSchema) .strict();

export const isJSONRPCRequest = (value: unknown): value is JSONRPCRequest => JSONRPCRequestSchema.safeParse(value).success;

/**

• A notification which does not expect a response. */ export const JSONRPCNotificationSchema = z .object({ jsonrpc: z.literal(JSONRPC_VERSION), }) .merge(NotificationSchema) .strict();

export const isJSONRPCNotification = ( value: unknown ): value is JSONRPCNotification => JSONRPCNotificationSchema.safeParse(value).success;

/**

• A successful (non-error) response to a request. */ export const JSONRPCResponseSchema = z .object({ jsonrpc: z.literal(JSONRPC_VERSION), id: RequestIdSchema, result: ResultSchema, }) .strict();

export const isJSONRPCResponse = (value: unknown): value is JSONRPCResponse => JSONRPCResponseSchema.safeParse(value).success;

/**

• Error codes defined by the JSON-RPC specification. */ export enum ErrorCode { // SDK error codes ConnectionClosed = -32000, RequestTimeout = -32001,

// Standard JSON-RPC error codes ParseError = -32700, InvalidRequest = -32600, MethodNotFound = -32601, InvalidParams = -32602, InternalError = -32603, }

/**

• A response to a request that indicates an error occurred. / export const JSONRPCErrorSchema = z .object({ jsonrpc: z.literal(JSONRPC_VERSION), id: RequestIdSchema, error: z.object({ /* * The error type that occurred. / code: z.number().int(), /* * A short description of the error. The message SHOULD be limited to a concise single sentence. / message: z.string(), /* * Additional information about the error. The value of this member is defined by the sender (e.g. detailed error information, nested errors etc.). */ data: z.optional(z.unknown()), }), }) .strict();