import { type LanguageModel, type ModelMessage } from 'ai';
import type { HarnessConfig } from '../../types/index.js';
export interface ResolvedAutoCompaction {
    maxMessages: number | undefined;
    maxTokens: number | undefined;
    strategy: 'truncate' | 'summarize';
    summaryModel?: LanguageModel;
}
export declare function estimateHistoryTokens(messages: ModelMessage[]): number;
export declare function resolveEffectiveAutoCompaction(config: HarnessConfig): ResolvedAutoCompaction | null;
/**
 * Truncate tool-call arguments and tool-result outputs in older messages.
 * Cheap pre-compaction pass that reclaims significant context without an
 * LLM call — tool outputs are the largest context consumers but least
 * important for conversational continuity. (DeepAgents / Cloudflare pattern)
 *
 * Only truncates messages BEFORE `recentKeep`; recent messages stay intact.
 */
export declare function truncateToolArguments(messages: ModelMessage[], recentKeep: number): ModelMessage[];
/**
 * Strip orphaned tool results whose matching tool call was truncated,
 * and orphaned tool calls whose results were truncated.
 * OpenAI rejects conversations with mismatched tool call/result pairs.
 */
export declare function stripOrphanedToolPairs(messages: ModelMessage[]): ModelMessage[];
export declare function autoCompactMessages(messages: ModelMessage[], config: HarnessConfig, resolved: ResolvedAutoCompaction, opts?: {
    defaultModel?: LanguageModel;
    abortSignal?: AbortSignal;
}): Promise<{
    messages: ModelMessage[];
    compacted: boolean;
}>;