import type { ChatMessage } from "../../types.js";
import type { PersistedContextUsage } from "../../store/history.js";
import type { PersistedRouteUsage } from "./session-usage-ledger.js";
import { type ContextSnapshotV1 } from "../../llm/context-snapshot.js";
import type { PersistencePort, SaveSessionOptions } from "../ports/persistence-port.js";
/**
 * A session is worth writing (and therefore worth resuming) once it holds a
 * real user turn or a compaction memory. Shared by every persistence trigger
 * so `persistNow`, autosave, and the exit epilogue never disagree.
 */
export declare function hasPersistableHistory(messages: readonly ChatMessage[]): boolean;
/** Ordered whole-session snapshots shared by every persistence trigger. */
export declare class SessionPersistenceQueue {
    private readonly port;
    private writerGeneration;
    private revision;
    private chain;
    constructor(port: PersistencePort);
    rebind(_loadedRevision?: number | undefined): void;
    newSession(): void;
    save(messages: readonly ChatMessage[], options: Omit<SaveSessionOptions, "revision">): Promise<void>;
}
export declare function mintSessionId(): string;
export declare function pathBackedMessages(messages: readonly ChatMessage[]): ChatMessage[];
export declare function persistedContextUsage(snapshot: ContextSnapshotV1 | undefined, routeUsage?: readonly PersistedRouteUsage[] | undefined): PersistedContextUsage | undefined;