import type { ChatMessage } from "../types.js";
export declare const COMPACTION_RETRY_COOLDOWN_MS = 60000;
export declare const COMPACTION_MAX_ATTEMPTS = 3;
export interface CompactionAttemptKeyInput {
    readonly messages: readonly ChatMessage[];
    readonly provider: string;
    readonly model: string;
    readonly dialect: string;
    readonly triggerTokens: number;
    readonly schemaHash: string;
    readonly durableEnvelope?: string | undefined;
}
export declare function compactionAttemptKey(input: CompactionAttemptKeyInput): string;
export declare class CompactionAttemptLedger {
    private readonly cooldownMs;
    private readonly now;
    private readonly maxAttempts;
    private readonly failures;
    constructor(cooldownMs?: number, now?: () => number, maxAttempts?: number);
    isSuppressed(key: string): boolean;
    recordFailure(key: string): void;
    recordSuccess(key: string): void;
    attemptCount(key: string): number;
    isExhausted(key: string): boolean;
    clear(): void;
}