/**
 * [WHO]: Provides JsonlEvalSink (filesystem append-only adapter)
 * [FROM]: Depends on node:fs, node:path, node:url; ./types.js for EvalSink/EvalEventEnvelope/CreateEvalSinkOptions
 * [TO]: Constructed by eval/index.ts factory when adapter resolves to "jsonl"
 * [HERE]: extensions/builtin/sal/eval/jsonl-sink.ts - offline-friendly sink that appends one JSON object per line; useful for experiments that don't want a live backend, and for capturing replayable event traces
 *
 * Output schema: each line is a serialized EvalEventEnvelope. Downstream tools
 * (analysis scripts, bulk import to InsForge / Postgres / BigQuery) consume the
 * file directly. No transformation is applied — the file is the raw event log.
 */
import type { CreateEvalSinkOptions, EvalEventEnvelope, EvalSink } from "./types.js";
export declare class JsonlEvalSink implements EvalSink {
    readonly enabled = true;
    private filePath;
    private pending;
    private batchIntervalMs;
    private flushTimer;
    private closed;
    private onDiagnostic;
    constructor(options: CreateEvalSinkOptions);
    sendEvent(event: EvalEventEnvelope): Promise<void>;
    flush(): Promise<void>;
    close(): Promise<void>;
    private scheduleFlush;
    private writeLines;
    private reportDiagnostic;
}