import { BaseMessage, MessageContentComplex } from '@langchain/core/messages';
import type { AnthropicMessage } from '@/types/messages';
type MessageWithContent = {
    content?: string | MessageContentComplex[];
};
/**
 * Anthropic API: Adds cache control to the appropriate user messages in the payload.
 * Strips ALL existing cache control (both Anthropic and Bedrock formats) from all messages,
 * then adds fresh cache control to the last 2 user messages in a single backward pass.
 * This ensures we don't accumulate stale cache points across multiple turns.
 * Returns a new array - only clones messages that require modification.
 * @param messages - The array of message objects.
 * @returns - A new array of message objects with cache control added.
 */
export declare function addCacheControl<T extends AnthropicMessage | BaseMessage>(messages: T[]): T[];
/**
 * Removes all Anthropic cache_control fields from messages
 * Used when switching from Anthropic to Bedrock provider
 * Returns a new array - only clones messages that require modification.
 */
export declare function stripAnthropicCacheControl<T extends MessageWithContent>(messages: T[]): T[];
/**
 * Removes all Bedrock cachePoint blocks from messages
 * Used when switching from Bedrock to Anthropic provider
 * Returns a new array - only clones messages that require modification.
 */
export declare function stripBedrockCacheControl<T extends MessageWithContent>(messages: T[]): T[];
/**
 * Adds Bedrock Converse API cache points using "Stable Prefix Caching" strategy.
 *
 * STRATEGY: Place cache point after the LAST ASSISTANT message only.
 * This ensures the prefix (everything before the cache point) remains STABLE
 * as the conversation grows, maximizing cache hits.
 *
 * Why this works:
 * - System message has its own cachePoint (added in AgentContext)
 * - Tools have their own cachePoint (added in IllumaBedrockConverse)
 * - Conversation history grows, but the PREFIX stays the same
 * - Only the NEW user message is uncached (it's always different)
 *
 * Example conversation flow:
 * Request 1: [System+cachePoint][Tools+cachePoint][User1] → No conversation cache yet
 * Request 2: [System][Tools][User1][Assistant1+cachePoint][User2] → Cache User1+Assistant1
 * Request 3: [System][Tools][User1][Assistant1][User2][Assistant2+cachePoint][User3]
 *            → Cache reads User1+A1+User2+A2, cache writes new portion
 *
 * Claude's "Simplified Cache Management" automatically looks back up to 20 content
 * blocks from the cache checkpoint to find the longest matching prefix.
 *
 * @param messages - The array of message objects (excluding system message).
 * @returns - The updated array with a single cache point after the last assistant message.
 */
export declare function addBedrockCacheControl<T extends Partial<BaseMessage> & MessageWithContent>(messages: T[]): T[];
export {};