/** The only JSON-RPC version this server speaks. */
export declare const JSON_RPC_VERSION: "2.0";
/** A request/response correlation id. `null` is legal and means "unknown". */
export type JsonRpcId = string | number | null;
export interface JsonRpcErrorObject {
    readonly code: number;
    readonly message: string;
    readonly data?: unknown;
}
export interface JsonRpcRequest {
    readonly jsonrpc: typeof JSON_RPC_VERSION;
    readonly id: JsonRpcId;
    readonly method: string;
    readonly params?: unknown;
}
/** A request WITHOUT an id. JSON-RPC forbids replying to one. */
export interface JsonRpcNotification {
    readonly jsonrpc: typeof JSON_RPC_VERSION;
    readonly method: string;
    readonly params?: unknown;
}
export interface JsonRpcSuccess {
    readonly jsonrpc: typeof JSON_RPC_VERSION;
    readonly id: JsonRpcId;
    readonly result: unknown;
}
export interface JsonRpcFailure {
    readonly jsonrpc: typeof JSON_RPC_VERSION;
    readonly id: JsonRpcId;
    readonly error: JsonRpcErrorObject;
}
export type JsonRpcResponse = JsonRpcSuccess | JsonRpcFailure;
/** Standard JSON-RPC codes. The server adds no private codes of its own. */
export declare const JSON_RPC_PARSE_ERROR = -32700;
export declare const JSON_RPC_INVALID_REQUEST = -32600;
export declare const JSON_RPC_METHOD_NOT_FOUND = -32601;
export declare const JSON_RPC_INVALID_PARAMS = -32602;
export declare const JSON_RPC_INTERNAL_ERROR = -32603;
export declare function isPlainObject(value: unknown): value is Record<string, unknown>;
/** What one decoded line turned out to be. */
export type DecodedMessage = {
    readonly kind: 'request';
    readonly request: JsonRpcRequest;
} | {
    readonly kind: 'notification';
    readonly notification: JsonRpcNotification;
} | {
    readonly kind: 'invalid';
    readonly id: JsonRpcId;
    readonly error: JsonRpcErrorObject;
};
export declare function makeError(code: number, message: string, data?: unknown): JsonRpcErrorObject;
export declare function successResponse(id: JsonRpcId, result: unknown): JsonRpcSuccess;
export declare function failureResponse(id: JsonRpcId, error: JsonRpcErrorObject): JsonRpcFailure;
/**
 * Decode one frame.
 *
 * `undefined` means "nothing to answer" — an empty line, which is legal padding
 * and must not be reported as a parse error (an empty line is not a message the
 * peer sent; it is whitespace between messages).
 */
export declare function decodeMessage(line: string): DecodedMessage | undefined;
/**
 * Encode one frame for the wire. `JSON.stringify` escapes every newline inside
 * a string, which is what keeps one message on one line.
 */
export declare function encodeMessage(message: JsonRpcResponse | JsonRpcNotification): string;
/**
 * The buffer that turns an arbitrary chunking of bytes into whole lines.
 *
 * Needed because a pipe delivers no framing of its own: one `data` event may
 * carry half a message or three of them, and a server that parsed each event as
 * a message would work on a fast local pipe and fail on a loaded one.
 */
export declare class LineDecoder {
    private buffer;
    /** Feed a chunk; get back the complete lines it completed (no trailing newline). */
    push(chunk: string): string[];
    /** Whatever is left when the stream ends. A peer that never sent a newline still sent a message. */
    flush(): string[];
}