import { type LanguageModel, type TelemetryOptions } from "ai";
import { type HarnessSession, type StepResult, type ToolLoopHarnessConfig } from "#harness/types.js";
import { type HarnessModelMessage } from "#harness/messages.js";
import type { HistoryViewProjector } from "#shared/history-view.js";
import type { Publish } from "#harness/session-machine/commit.js";
import type { SessionAuthContext } from "#channel/types.js";
import type { Step } from "#harness/step/context.js";
import { type TurnPosition } from "#harness/session-machine/view.js";
/**
 * Processes the step result: extracts input requests, decides whether to
 * park, continue the tool loop, or terminate.
 */
/** What a step needs from the machine after its model call. */
/** `session.compact()`: summarizes the history now, then the session waits. */
export declare function compactHistory(step: Step): Promise<StepResult>;
export declare function replaceSessionHistory(session: HarnessSession, history: HarnessModelMessage[]): HarnessSession;
/**
 * Runs the compaction pipeline once if the session's input-token estimate
 * is over the configured threshold. Mutates neither input; returns the new
 * messages array and (possibly updated) session.
 *
 * Kept in the tool-loop (rather than the AI SDK's `prepareStep` hook) so
 * the compacted messages flow through the same `messages` variable the
 * harness uses to rebuild `session.history` after the step.
 */
export declare function maybeCompact(input: {
    readonly abortSignal?: AbortSignal;
    readonly auth: SessionAuthContext | null;
    /** A manual compaction runs between turns, so no turn's usage reports its summary calls. */
    readonly betweenTurns?: boolean;
    readonly emissionState: TurnPosition;
    readonly force?: boolean;
    readonly historyProjector?: HistoryViewProjector;
    readonly messages: HarnessModelMessage[];
    readonly model: LanguageModel;
    readonly publish: Publish;
    /** Model-visible prompt used only to decide whether durable history needs compaction. */
    readonly promptMessages?: readonly HarnessModelMessage[];
    readonly requestEnvelopeTokens?: number;
    readonly resolveModel: ToolLoopHarnessConfig["resolveModel"];
    readonly runtimeIdentity?: ToolLoopHarnessConfig["runtimeIdentity"];
    readonly session: HarnessSession;
    readonly telemetry?: TelemetryOptions;
}): Promise<{
    readonly compacted: boolean;
    /** The summary failed; `session` still counts the summary calls that finished. */
    readonly failure?: {
        readonly error: unknown;
    };
    readonly messages: HarnessModelMessage[];
    readonly session: HarnessSession;
}>;