import type { Message } from '../types/messages.js';
import type { AgentMiddleware } from './create-agent.js';
/**
 * Middleware that ships with the agent.
 *
 * Each is small on purpose: the seam matters more than the set, and an application's real policy is
 * usually its own. These cover the three every long-running agent needs — a transcript that does not
 * grow forever, secrets that never reach a provider, and a cap on tool use.
 */
export interface SummarizeOptions {
    /** Messages kept verbatim at the end of the transcript. Defaults to 6. */
    keepLast?: number;
    /** Summarizing starts once the transcript passes this many messages. Defaults to 20. */
    triggerAfter?: number;
    /** Turns the older messages into one summary. Usually a cheap model. */
    summarize: (messages: Message[]) => Promise<string> | string;
}
/**
 * Replaces the older half of a long transcript with a summary.
 *
 * An agent that runs for hours otherwise re-sends its whole history on every call, which costs more
 * each turn and eventually exceeds the context window.
 */
export declare function summarizeHistory(options: SummarizeOptions): AgentMiddleware;
/** Options for `redactMiddleware()`. */
export interface RedactOptions {
    /** Patterns replaced before a message reaches the provider. */
    patterns: readonly RegExp[];
    /** Text each match is replaced with. Defaults to `[redacted]`. */
    replacement?: string;
    /** Also redact what the model sends back, for anything written to logs or state. */
    redactOutput?: boolean;
}
/**
 * Redacts matching text from requests, and optionally from responses.
 *
 * For an agent whose transcript may contain a key, an account number, or anything else that should
 * not leave the process. The full security pipeline is in `nexus-ai-pro/security`; this is the small
 * version that needs no configuration.
 */
export declare function redactMessages(options: RedactOptions): AgentMiddleware;
/**
 * Caps how often a tool may be called in one run.
 *
 * A model that loops on the same call otherwise burns the iteration budget, and with an expensive
 * tool it burns money too.
 */
export declare function limitToolCalls(limits: Record<string, number>): AgentMiddleware;