import type { UserInputSignal } from "@threadbase-sh/agent-types";
export interface PayloadMeasurement {
    bytes: number;
    exceedsLimit: boolean;
}
/**
 * Serialize the signal and measure its byte size. Returns both the count and
 * whether it exceeds the supplied limit.
 *
 * Callers should refuse the input and return 413 SESSION_HISTORY_FULL when
 * `exceedsLimit` is true.
 */
export declare function measureSignalPayload(signal: UserInputSignal, limitBytes: number): PayloadMeasurement;
export interface TrajectoryConfig {
    trajectoryLogBytes: number;
    trajectoryLogTurns: number;
}
/**
 * Trajectory log trigger. Fires when EITHER:
 * - The session has reached a turn count that's a multiple of 5, starting at
 *   `trajectoryLogTurns` (default 20), OR
 * - The composed signal is >= `trajectoryLogBytes` (default 500 KB) regardless
 *   of turn count.
 *
 * Returning true means the caller should emit a WARN log line with current
 * size + turn count + percentage-of-limit info.
 */
export declare function shouldLogTrajectory(turnCount: number, bytes: number, cfg: TrajectoryConfig): boolean;
//# sourceMappingURL=payload-guard.d.ts.map