import type { EveMessage, EveMessagePart } from "#client/message-reducer-types.js";
type EveAssistantMessage = EveMessage & {
    readonly role: "assistant";
};
type EveRunPart = Extract<EveMessagePart, {
    readonly type: "text" | "reasoning";
}>;
declare function append(message: EveAssistantMessage, append: {
    readonly delta: string;
    readonly stepIndex: number;
    readonly type: EveRunPart["type"];
}): EveAssistantMessage;
declare function upsert(message: EveAssistantMessage, next: EveRunPart): EveAssistantMessage;
export declare const messageRun: {
    readonly append: typeof append;
    readonly upsert: typeof upsert;
};
export {};