import type { ExtensionAPI } from "./pi.js";
import type { PlanItem } from "./wire.js";
/** The kept state of one subagent, merged across its lifecycle events. */
export interface AgentState {
    id: string;
    type?: string;
    description?: string;
    /** raw pi-subagents lifecycle status. */
    status?: string;
    startedAt?: number;
    durationMs?: number;
    result?: string;
    error?: string;
}
/** Lifecycle rank: pending(0) < in_progress(1) < terminal(2). pi can emit out of order. */
export declare function statusRank(status: string | undefined): number;
/** Merge an incoming lifecycle event into the kept state: preserve type/description/result,
 *  never downgrade status, keep the specific terminal reason over a generic `failed`.
 *  (Port of pi-acp's mergeSubagent.) */
export declare function mergeAgentState(prev: AgentState | undefined, incoming: AgentState): AgentState;
/** An AgentState → a `kind:"agent"` plan item for the model's Agents group. */
export declare function toAgentItem(a: AgentState): PlanItem;
export interface AgentSource {
    /** Current fleet as agent plan items. */
    items(): PlanItem[];
    /** Raw kept state (active + finished), for callers that need more than plan items. */
    fleet(): AgentState[];
}
/**
 * Subscribe the subagent lifecycle and maintain the merged fleet (a live Map of AgentState).
 * `onChange` fires on every update so the caller can repaint.
 */
export declare function installAgentSource(pi: ExtensionAPI, onChange: () => void): AgentSource;