import type { ModelMessage, SystemModelMessage } from "ai";
import type { StepCatalog } from "#execution/catalog/step-catalog.js";
import { createCurrentMessages } from "#harness/current-messages.js";
import { type HarnessModelMessage, type UserModelMessage } from "#harness/messages.js";
import type { ModelProfile } from "#harness/model-profile.js";
import type { Step } from "#harness/step/context.js";
import type { HarnessSession } from "#harness/types.js";
export type RequestMessages = ReturnType<typeof createCurrentMessages>;
/**
 * The messages one model call sends: the durable prompt, then the step's system instructions and
 * announcements. Announcements persist ahead of the new input, or after earlier tool results on a
 * continuation, so later requests keep the full prefix.
 */
export declare function requestMessages(step: Step, input: {
    readonly messages: readonly HarnessModelMessage[];
    readonly projectedMessages: readonly HarnessModelMessage[];
    readonly turnMessages: readonly UserModelMessage[];
    readonly catalog: StepCatalog;
    readonly hidesHeldText: boolean;
    readonly pendingApprovalsNote: string | undefined;
}): RequestMessages;
/** The call's system instructions: a retry's note, the agent's system prompt, then the step's. */
export declare function modelInstructions(input: {
    readonly session: HarnessSession;
    readonly systemMessages: readonly SystemModelMessage[];
    readonly anthropicCache: ModelProfile["anthropicCache"];
    readonly extraSystemNote?: string;
}): SystemModelMessage | string | undefined;
/** A retry's note, trailing the call's messages. */
export declare function withTrailingUserNote(messages: readonly ModelMessage[], note?: string): ModelMessage[];
export declare function mergeSystemInstructions(instructions: readonly SystemModelMessage[]): SystemModelMessage | undefined;