import type { Session } from '../types/index.js';
import type { MemoryService } from './MemoryService.js';
/**
 * Preloads relevant memories into the system prompt before each LLM call.
 *
 * This is NOT a tool the LLM calls. It is a Runtime-level middleware that:
 * 1. Takes the user's latest message as a search query
 * 2. Searches long-term memory for relevant context
 * 3. Formats matching memories as a markdown section
 * 4. Truncates the output to fit within the allocated token budget
 *
 * The maxTokens parameter is mandatory. If the formatted output exceeds
 * maxTokens, memories are dropped in lowest-relevance-first order until
 * the output fits.
 */
export declare function preloadMemoryContext(memoryService: MemoryService, session: Session, userInput: string, maxTokens: number): Promise<string | null>;