import type { ModelMessage } from 'ai';
import type { Session } from '../types/session.js';
import type { RunState } from './durable/types.js';
import type { RunStore } from './durable/RunStore.js';
/** Legacy compaction summaries were stored as the first model message with this prefix. */
export declare const COMPACTION_SUMMARY_PREFIX = "[Conversation summary \u2014 earlier turns were compacted]";
/**
 * Remove `role: 'system'` entries from a run's model message array. Legacy compaction
 * summaries and other framework notes are routed into the system-note channel so context
 * is preserved. Idempotent: already-clean state is not mutated.
 */
export declare function sanitizeRunStateMessages(runState: RunState): boolean;
/**
 * A caller supplied a message array the runtime refuses. Carries a `name` tag rather than
 * relying on `instanceof`, which breaks when a consumer resolves two copies of core — the
 * same reason `FlowDriftError` is tagged. Transports map this to 400, not 500.
 */
export declare class InvalidCallerMessagesError extends Error {
    readonly name = "InvalidCallerMessagesError";
    readonly field: 'seedMessages' | 'historyDelta';
    readonly index: number;
    constructor(field: 'seedMessages' | 'historyDelta', index: number);
}
/** Caller-supplied message arrays must not seed system-role entries into the transcript. */
export declare function rejectSystemRoleInCallerMessages(messages: readonly ModelMessage[], context: 'seedMessages' | 'historyDelta'): void;
/**
 * Strip legacy `role: 'system'` entries from a session transcript on read.
 * Text is dropped here — run state already routes it into system notes for
 * model calls, and mirroring it in the client transcript would duplicate context
 * if a consumer round-tripped messages back in.
 */
export declare function sanitizeSessionMessages(session: Pick<Session, 'messages'>): boolean;
/** Load run state and strip legacy system-role messages in memory (no write). */
export declare function loadSanitizedRunState(runStore: RunStore, runId: string): Promise<RunState | null>;