export interface GmailMessage {
    id?: string;
    raw?: string;
    headers?: Array<{
        name: string;
        value: string;
    }>;
    labelIds?: string[];
    snippet?: string;
    body?: string;
    subject?: string;
    from?: string;
    to?: string;
}
export declare class GmailAPI {
    private static GMAIL_REDIRECT_URI;
    private constructor();
    private static getOAuth2Client;
    private static getGmail;
    static getAccessToken(clientId: string, clientSecret: string, refreshToken: string): Promise<string>;
    static listMessages(clientId: string, clientSecret: string, refreshToken: string, query: string): Promise<GmailMessage[]>;
    static getMessage(clientId: string, clientSecret: string, refreshToken: string, msgId: string): Promise<GmailMessage>;
}