/**
 * In-turn context guard for the OpenAI-compatible chat-completions loop.
 *
 * `openaiChatCompletionsBase` runs its own hand-written tool loop
 * (`for step < maxSteps` → `streamOneStep` → `executeToolBatch`) and appends an
 * assistant tool-call message plus one `role: "tool"` message per result on
 * every step. Nothing bounded that growth: the loop had no context guard of any
 * kind, so a long agentic run walked into a provider "context length exceeded"
 * after dozens of tool calls and lost every completed step.
 *
 * This is the widest-reach gap in the codebase — the chat-completions base
 * backs LiteLLM, DeepSeek, OpenRouter, NVIDIA NIM, LM Studio, llama.cpp and
 * every `openai-compatible` provider.
 *
 * The reclaim POLICY lives in `loopGuardCore` and is shared with the other
 * provider loops. This module owns only the shape mapping: OpenAI-compatible
 * messages in, neutral entries out, plan applied back.
 */
import type { OpenAICompatChatMessage } from "../types/index.js";
/**
 * Reclaim context budget from a chat-completions loop's conversation.
 *
 * Returns a NEW array when it acted, or `undefined` when the loop fits and the
 * history must be left byte-identical — any rewrite invalidates the provider's
 * cached prompt prefix, so "no change" has to mean no change.
 *
 * @param observedPromptTokens the provider's reported prompt token count for
 * the previous step, used to calibrate the char-based estimate for free.
 * @param previousSentEstimate this guard's own estimate for the request that
 * produced `observedPromptTokens`. The two must describe the SAME request.
 * @param onSentEstimate receives the estimate for the request about to be sent,
 * so the caller can feed it back as the next step's `previousSentEstimate`.
 */
export declare function guardOpenAICompatConversation(args: {
    conversation: OpenAICompatChatMessage[];
    availableInputTokens: number;
    fixedOverheadTokens: number;
    provider?: string;
    observedPromptTokens?: number;
    previousSentEstimate?: number;
    onSentEstimate?: (tokens: number) => void;
}): OpenAICompatChatMessage[] | undefined;