/**
 * In-turn context guard for Anthropic-shaped agent loops.
 *
 * The direct Anthropic loop (`providers/anthropic/client.ts`) grows a
 * `conversation` array on every step: an assistant message carrying `tool_use`
 * blocks, then a user message carrying the matching `tool_result` blocks. It
 * had no in-turn guard, so a long agentic run overflowed the window mid-loop
 * and lost every completed step.
 *
 * Granularity differs from the OpenAI-compatible shape: there, each tool result
 * is its own message; here, ONE user message carries every `tool_result` for a
 * step. That makes the message the natural batch unit — dropping an assistant
 * `tool_use` message together with its following `tool_result` message can
 * never orphan a block, which Anthropic rejects outright.
 *
 * The reclaim POLICY lives in `loopGuardCore` and is shared with the other
 * provider loops. This module owns only the shape mapping.
 */
import type { AnthropicGuardMessage, LoopGuardPlan } from "../types/index.js";
/** Marker left where dropped history used to be. */
export declare const ANTHROPIC_ELISION_NOTE = "[Earlier tool exchanges were removed to fit the context window.]";
/**
 * Text-level preview used for an oversized `tool_result` payload. Exposed so
 * the caller can apply it to its OWN block type — this module never rebuilds
 * the caller's messages, which keeps it free of generic-spread assignability
 * problems and of the double type assertions Critical Rule 14 forbids.
 */
export declare function previewAnthropicToolResultText(text: string): string;
/** True when this message carries `tool_result` blocks worth previewing. */
export declare function isAnthropicToolResultMessage(message: AnthropicGuardMessage): boolean;
/**
 * Decide what to reclaim from an Anthropic-shaped agent loop.
 *
 * Returns `undefined` when the loop still fits — the caller must then leave its
 * history byte-identical, because any rewrite invalidates the rolling
 * `cache_control` prefix this path depends on.
 */
export declare function planAnthropicLoopReclaim(args: {
    conversation: readonly AnthropicGuardMessage[];
    availableInputTokens: number;
    fixedOverheadTokens: number;
    provider?: string;
    observedPromptTokens?: number;
    previousSentEstimate?: number;
    onSentEstimate?: (tokens: number) => void;
    observedDescribesCurrentPayload?: boolean;
}): LoopGuardPlan | undefined;