/**
 * Dev-mode port resolution utilities.
 *
 * Provides a `listen` wrapper that automatically retries the next port when
 * the requested one is already in use, and writes the resolved port to a
 * well-known temp file so the CLI / frontend can discover it.
 *
 * Port affinity: when a port file already exists (e.g. after a tsx watch
 * restart), the saved port is tried FIRST so the backend stays on the same
 * port the frontend was configured with.
 *
 * This module is dev-only and should never run in production.
 */
import type { Server } from "http";
/** Filename written next to the project `.env` so the CLI can read it. */
export declare const DEV_PORT_FILENAME = ".rebase-dev-port";
/**
 * Try to `listen` on `startPort`. If the port is busy (`EADDRINUSE`), increment
 * and retry up to `maxAttempts` times.
 *
 * When a port file already exists (written by a previous run), the saved port
 * is tried first to maintain port affinity across tsx watch restarts.
 *
 * Resolves with the port that was actually bound.
 *
 * @internal Not part of the stable public API. Exported only because the
 * official app template (`packages/cli/templates/template/backend/src/index.ts`
 * and `app/backend/src/index.ts`) calls it directly in dev mode. Its dev-only
 * port-affinity behavior is an implementation detail and may change without
 * a major version bump.
 */
export declare function listenWithPortRetry(server: Server, startPort: number, options?: {
    host?: string;
    maxAttempts?: number;
    /** Absolute path to write the resolved port file into.  Defaults to `process.cwd()`. */
    portFileDir?: string;
    /** Service key to include in the state file for MCP server auto-discovery. */
    serviceKey?: string;
}): Promise<number>;
/**
 * Clean up the dev port file and state file (call on graceful shutdown).
 *
 * @internal Not part of the stable public API. See {@link listenWithPortRetry}.
 */
export declare function cleanupDevPortFile(dir: string): void;