import type { AgentBasicInformation } from '../../book-2.0/agent-source/AgentBasicInformation';
import type { string_url, string_url_image } from '../../types/typeAliases';
/**
 * Options for resolving agent avatar URLs.
 *
 * @private utility of `<Chat/>`
 */
export type ResolveAgentAvatarImageUrlOptions = {
    /**
     * Agent metadata used for avatar resolution.
     */
    readonly agent: Pick<AgentBasicInformation, 'agentName' | 'permanentId' | 'meta'>;
    /**
     * Optional base URL used to resolve relative meta images and placeholders.
     */
    readonly baseUrl?: string_url;
};
/**
 * Resolve the fallback avatar URL for an agent.
 *
 * @private utility of `<Chat/>`
 */
export declare function resolveAgentAvatarFallbackUrl(options: ResolveAgentAvatarImageUrlOptions): string_url_image | null;
/**
 * Resolve the best avatar URL for an agent, preferring META IMAGE and falling back to placeholders.
 *
 * @private utility of `<Chat/>`
 */
export declare function resolveAgentAvatarImageUrl(options: ResolveAgentAvatarImageUrlOptions): string_url_image | null;