@cosmjs/json-rpc

npm install @cosmjs/json-rpc

interface SimpleMessagingConnection<Request, Response> {
  readonly responseStream: Stream<Response>;
  readonly sendRequest: (request: Request) => void;
}

import { parseJsonRpcResponse, isJsonRpcErrorResponse } from "@cosmjs/json-rpc";

const response = parseJsonRpcResponse(data);

if (isJsonRpcErrorResponse(response)) {
  console.error("RPC error:", response.error.message);
} else {
  console.info("Result:", response.result);
}

interface JsonRpcRequest {
  readonly jsonrpc: "2.0";
  readonly id: JsonRpcId;
  readonly method: string;
  readonly params: JsonCompatibleArray | JsonCompatibleDictionary;
}

interface JsonRpcSuccessResponse {
  readonly jsonrpc: "2.0";
  readonly id: JsonRpcId;
  readonly result: any;
}

interface JsonRpcErrorResponse {
  readonly jsonrpc: "2.0";
  readonly id: JsonRpcId | null;
  readonly error: JsonRpcError;
}

interface JsonRpcError {
  readonly code: number;
  readonly message: string;
  readonly data?: JsonCompatibleValue;
}

type JsonRpcId = number | string;

type JsonRpcResponse = JsonRpcSuccessResponse | JsonRpcErrorResponse;