/**
 * Error thrown when a thread or run is not found.
 * The `status` property is recognized by Koa/Egg error handling
 * to set the corresponding HTTP response status code.
 */
export declare class AgentNotFoundError extends Error {
    status: number;
    constructor(message: string);
}
/**
 * Error thrown when an operation conflicts with the current state
 * (e.g., cancelling a completed run).
 */
export declare class AgentConflictError extends Error {
    status: number;
    constructor(message: string);
}
/**
 * Error thrown when a RunBuilder state transition is invalid
 * (e.g., calling `complete()` on a queued run).
 */
export declare class InvalidRunStateTransitionError extends Error {
    status: number;
    constructor(from: string, to: string);
}