import ITokenProvider from './ITokenProvider';
import Token from './Token';
/**
 * Type for the callback function that retrieves tokens from external sources.
 */
export type TokenCallback = () => Promise<string>;
/**
 * A token provider that delegates token retrieval to an external callback function.
 * Useful for integrating with secret managers, vaults, or other token sources.
 */
export default class ExternalTokenProvider implements ITokenProvider {
    private readonly getTokenCallback;
    private readonly parseJWT;
    private readonly providerName;
    /**
     * Creates a new ExternalTokenProvider.
     * @param getToken - Callback function that returns the access token string
     * @param options - Optional configuration
     * @param options.parseJWT - If true, attempt to extract expiration from JWT payload (default: true)
     * @param options.name - Custom name for this provider (default: "ExternalTokenProvider")
     */
    constructor(getToken: TokenCallback, options?: {
        parseJWT?: boolean;
        name?: string;
    });
    getToken(): Promise<Token>;
    getName(): string;
}