type CodexRedemptionConfirmationClaims = {
    version: 1;
    attemptId: string;
    workspaceId: string;
    credentialId: string;
    creditId: string;
    subjectId: string;
    browserSessionHash: string;
    expiresAt: number;
};
export declare function hashCodexBrowserSession(sessionId: string): Promise<string>;
/** Five-minute, session-bound, HMAC-confirmed browser mutation token. */
export declare function signCodexRedemptionConfirmation(secret: string, claims: CodexRedemptionConfirmationClaims): Promise<string>;
export declare function verifyCodexRedemptionConfirmation(secret: string, token: string, now?: number): Promise<CodexRedemptionConfirmationClaims | null>;
export type { CodexRedemptionConfirmationClaims };