import { IAttachmentOptions } from '../template/template.interface';
type ContentEnginePayload = {
    [key: string]: string | {
        key: string;
    }[] | {
        key: string | number;
    } | string[] | number[] | boolean | number | undefined | IAttachmentOptions | IAttachmentOptions[] | Record<string, unknown>;
};
export interface IContentEngine {
    compileTemplate: (content: string, payload: ContentEnginePayload) => string;
    extractMessageVariables: (content: string) => Array<string>;
}
export declare class HandlebarsContentEngine implements IContentEngine {
    compileTemplate(content: string, payload: ContentEnginePayload): string;
    extractMessageVariables(content: string): string[];
}
export {};
//# sourceMappingURL=content.engine.d.ts.map