/** Where `agency test` prints. Under `--json`, stdout carries exactly one
 *  document and every human line goes to stderr. */
import type { TestReport } from "./testReport.js";
export type OutputStream = "stdout" | "stderr";
export type TestOutput = {
    kind: "human" | "json";
    /** A human-readable line. Defaults to stdout. */
    line(msg: string, stream?: OutputStream): void;
    /** The document, once, at the end. A no-op in human mode. */
    document(report: TestReport): void;
};
export type OutputWriters = {
    stdout: (text: string) => void;
    stderr: (text: string) => void;
};
export declare function humanOutput(writers?: OutputWriters): TestOutput;
export declare function jsonOutput(writers?: OutputWriters): TestOutput;