/**
 * Bounded text accumulation for external-CLI child output.
 *
 * The codex/claude backends read child stdout/stderr in the PARENT process. A
 * verbose or crash-looping child (or one that emits a giant newline-free blob)
 * would otherwise grow the parent's resident memory without bound. These caps
 * keep a single runaway subagent from OOM-ing the host pi process. The workflow
 * worker's memory cap explicitly excludes subprocess memory, and the `run_agent`
 * path has no cap at all, so the guard has to live here.
 */
export declare const MAX_STDERR_CHARS: number;
/**
 * Max length of a single un-terminated stdout line. Line-delimited JSON events
 * are far smaller than this; a line this large without a newline means the
 * stream is broken, so the backend aborts the child and fails the run with a
 * clear error rather than buffering forever (or silently dropping real output).
 */
export declare const MAX_STDOUT_LINE_CHARS: number;
export interface BoundedBuffer {
    append(chunk: string): void;
    /**
     * The retained text. When the input exceeded the cap, the head and the tail
     * are both kept with an elision marker between them, so the start AND the end
     * of a failure (where the real error usually is) survive truncation.
     */
    text(): string;
    overflowed(): boolean;
}
export declare function createBoundedBuffer(maxChars: number): BoundedBuffer;