export type ReplTurnOutcome = 'success' | 'failed' | 'interrupted';
export type ReplTurnEvent = {
    type: 'turn-start';
    agentId: string;
    threadId: string;
    startedAt: number;
} | {
    type: 'text-delta';
    delta: string;
} | {
    type: 'status';
    message: string;
} | {
    type: 'tool-call';
    toolCall: {
        toolCallId: string;
        toolName: string;
        args?: unknown;
    };
} | {
    type: 'tool-start';
    toolName: string;
    detail?: string;
} | {
    type: 'tool-update';
    toolName: string;
    detail: string;
} | {
    type: 'tool-end';
    toolName: string;
    outcome: 'success' | 'failed';
} | {
    type: 'thread-update';
    agentId: string;
    threadId: string;
    reason: string;
} | {
    type: 'warning';
    message: string;
} | {
    type: 'error';
    message: string;
} | {
    type: 'turn-end';
    outcome: ReplTurnOutcome;
    finishedAt: number;
};
export interface ReplTurnState {
    agentId: string;
    threadId: string;
    startedAt: number | null;
    finishedAt: number | null;
    outcome: ReplTurnOutcome | null;
    assistantText: string;
    activity: string[];
    toolStarts: number;
}
export declare function createTurnState(): ReplTurnState;
export declare function reduceTurnEvent(state: ReplTurnState, event: ReplTurnEvent): ReplTurnState;
export declare function buildCollapsedActivitySummary(state: ReplTurnState): string;