import type { VertexAnthropicCacheInput, VertexAnthropicCacheOutput } from "../types/index.js";
/**
 * Annotate a native Vertex+Claude request with prompt-cache breakpoints.
 *
 * Budget allocation (max 4 markers):
 *   1. The stable prefix — the last system block when a system prompt is
 *      present (this single marker caches `tools + system`, since system
 *      renders after tools); otherwise the last tool definition.
 *   2-4. A rolling breakpoint on the last few messages, so the
 *      growing-but-now-stable conversation history is cached and only the
 *      newest turn is billed as fresh input.
 *
 * Pure: the inputs are cloned, never mutated.
 */
export declare function applyVertexAnthropicCacheBreakpoints(input: VertexAnthropicCacheInput): VertexAnthropicCacheOutput;
