/**
 * Deterministic source-format detection (issue #3709).
 *
 * Detection inspects only the already-read source bytes: a bounded leading
 * sample decides JSONL-vs-JSON and provider by envelope markers. An explicit
 * `--provider` selection narrows candidates; a sample that matches a different
 * provider than requested fails closed with `format_mismatch`. Detection never
 * guesses: a sample matching no supported envelope fails with
 * `unsupported_format` rather than falling back to a speculative parse.
 */
import { type SessionImportFormatId, type SessionImportProviderId } from "./types";
export interface SessionImportDetection {
    provider: SessionImportProviderId;
    format: SessionImportFormatId;
}
/**
 * Detect the provider/format of an explicit transcript file.
 *
 * @param text Full source text (already size-bounded by the caller).
 * @param requestedProvider Explicit provider selection; undefined = auto.
 */
export declare function detectSessionImportFormat(text: string, requestedProvider: SessionImportProviderId | undefined): SessionImportDetection;