/**
 * Per-prompt difficulty classifier for the `auto` thinking level.
 *
 * Asks a {@link ChoiceQuestion} when multiple supported online tiers exist,
 * short-circuiting without a judge request when zero or one tier is available.
 * For task-spawned turns, it considers the delegator's `solutionSpace` alone.
 * It maps the selected level to a concrete {@link Effort} and clamps it into
 * the active model's supported range (never below {@link Effort.Low}).
 * The judge comes from the live `judge` role chain. A local on-device candidate
 * gets the coarser
 * `trivial|moderate|hard` question (3-class is more reliable
 * than 4-way ordinal on sub-2B models), mapped to `low|high|xhigh`.
 *
 * Throws on any failure (no judge, no key, unparseable output, abort/timeout);
 * the caller falls back to a concrete level and continues the turn.
 */
import type { AgentTelemetryConfig } from "@oh-my-pi/pi-agent-core";
import { Effort, type Model } from "@oh-my-pi/pi-ai";
import type { ModelRegistry } from "../config/model-registry.js";
import type { Settings } from "../config/settings.js";
import { type JudgmentUsage } from "../judgment/index.js";
/** The turn to classify. */
export interface DifficultyInput {
    /** The prompt text the agent is about to act on. */
    request: string;
    /**
     * Delegator's description of how open-ended the subtask is (task `solutionSpace` field).
     * When non-blank it replaces `request` as the sole classification input.
     */
    solutionSpace?: string;
}
export interface ClassifyDifficultyDeps {
    settings: Settings;
    registry: ModelRegistry;
    model: Model;
    sessionId?: string;
    signal?: AbortSignal;
    metadataResolver?: (provider: string) => Record<string, unknown> | undefined;
    onUsage?: (usage: JudgmentUsage) => void;
    telemetry?: AgentTelemetryConfig;
}
/**
 * Classify `input` and return a concrete effort clamped to `deps.model`,
 * or `undefined` when the model has no controllable effort surface or no
 * supported effort under the active ceiling (auto has nothing to pick — the
 * caller falls back to its provisional auto level).
 * @throws when the backend cannot produce a usable classification.
 */
export declare function classifyDifficulty(input: DifficultyInput, deps: ClassifyDifficultyDeps): Promise<Effort | undefined>;