import type { EveAgentReducer } from "#client/reducer.js";
/** One user message or completed assistant message in a {@link TranscriptData}. */
export interface TranscriptMessage {
    readonly role: "assistant" | "user";
    readonly text: string;
}
/** Text-only conversation projected by {@link transcriptReducer}. */
export interface TranscriptData {
    /** Messages since the session's last clear, oldest first. */
    readonly messages: readonly TranscriptMessage[];
}
/** Options for {@link transcriptReducer}. */
export interface TranscriptReducerOptions {
    /**
     * Most recent messages kept; older ones are dropped as new ones arrive.
     * A positive integer. Unbounded when omitted.
     */
    readonly maxMessages?: number;
}
/**
 * Creates a reducer that projects a session's stream into its text
 * conversation: user message text and completed assistant text, oldest
 * first.
 *
 * Reasoning, tool calls and results, attachments, approvals, and assistant
 * output that never completed are left out. A `context.cleared` event, or a
 * reset that ended a stranded session, starts the transcript over, so text
 * the session no longer holds is never returned. Client projection events
 * such as optimistic submissions are ignored; the transcript reflects only
 * durable events.
 *
 * @example
 * ```ts
 * import { transcriptReducer } from "eve/client";
 * import { sessions } from "eve/server";
 *
 * const reducer = transcriptReducer({ maxMessages: 40 });
 * let transcript = reducer.initial();
 * for await (const event of sessions.attach(sessionId).stream({ follow: false })) {
 *   transcript = reducer.reduce(transcript, event);
 * }
 * ```
 *
 * @throws When `maxMessages` is not a positive integer.
 */
export declare function transcriptReducer(options?: TranscriptReducerOptions): EveAgentReducer<TranscriptData>;