/**
 * [WHO]: TokenSaveStreamAccumulator for bounded streaming-mode output collection
 * [FROM]: No runtime dependencies
 * [TO]: Consumed by extensions/builtin/token-save/runner.ts and tests
 * [HERE]: extensions/builtin/token-save/stream.ts - stream-mode raw capture guardrail
 */
export interface TokenSaveStreamSnapshot {
    text: string;
    totalBytes: number;
    truncated: boolean;
}
export declare class TokenSaveStreamAccumulator {
    private readonly maxBytes;
    private chunks;
    private bytes;
    private truncated;
    constructor(maxBytes?: number);
    push(chunk: string): void;
    snapshot(): TokenSaveStreamSnapshot;
}