import type { DataSource, EntityManager } from 'typeorm';
/**
 * Runs the provided callback inside a transaction and exposes the active transaction manager.
 *
 * If a transaction is already active, the callback is executed as a nested TypeORM transaction on
 * the current manager. Starting a transaction from inside a readonly context is rejected because
 * writes must not escape the readonly boundary. Within the callback, injected TypeORM repositories
 * automatically resolve against the active transaction manager, so repository operations join the
 * same transaction without requiring manual rebinding.
 *
 * @template T
 * @param dataSource The TypeORM data source used to start the transaction when none is active.
 * @param runInTransaction Async callback that receives the transaction-bound entity manager.
 * Injected TypeORM repositories used inside this callback automatically participate in the same
 * transaction context.
 * @returns The value returned by `runInTransaction`.
 * @throws {Error} If called while a readonly context is active.
 */
export declare function transaction<T>(dataSource: DataSource, runInTransaction: (entityManager: EntityManager) => Promise<T>): Promise<T>;
export declare function createTransactionManagerProxy(manager: EntityManager): EntityManager;