import { Buffer } from 'buffer';
/** Wire channel identifiers for the binary channel-prefix protocol. */
export declare enum ShellChannel {
    STDIN = 0,
    STDOUT = 1,
    STDERR = 2,
    STATUS = 3,
    RESIZE = 4,
    HEARTBEAT = 5,
    CLOSE = 255,
    /** Sentinel for unrecognised channel bytes — not a wire value. */
    UNKNOWN = -1
}
/** A single decoded WebSocket frame from the shell stream. */
export interface ShellFrame {
    /** The channel this frame belongs to. UNKNOWN for unrecognised channel bytes. */
    channel: ShellChannel;
    /** The original channel byte from the wire. */
    rawChannelByte: number;
    /** Raw bytes of the frame payload (everything after the channel byte). */
    payload: Buffer;
    /** Decode payload as UTF-8 text (replacement char on invalid bytes). */
    readonly text: string;
    /** Parse payload as JSON. Throws SyntaxError if payload is not valid JSON. */
    json(): Record<string, unknown>;
}
/** Maximum frame size — matches DP WebSocketFlowController limit. */
export declare const MAX_FRAME_SIZE: number;
/**
 * Encodes and decodes binary channel-prefix WebSocket frames.
 * Stateless — a single instance is safe to reuse across frames.
 */
export declare class ShellFramer {
    /** Decode one raw WebSocket binary message into a ShellFrame. */
    decode(frame: Buffer): ShellFrame;
    /** Encode keyboard input or paste data as a STDIN frame. */
    encodeStdin(data: string | Buffer): Buffer;
    /** Encode a terminal resize event as a RESIZE frame. */
    encodeResize(width: number, height: number): Buffer;
    /** Encode an app-level heartbeat frame (channel 0x05, empty payload). */
    encodeHeartbeat(): Buffer;
    /** Encode a graceful-shutdown CLOSE frame (empty payload). */
    encodeClose(): Buffer;
}
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