import type { ProviderRuntimeMetadata } from '../provider-runtime-metadata.js';
export declare class SessionHeaderUtils {
    private static readIdentifier;
    private static ensureRuntimeMetadataCarrier;
    static ensureCodexSessionMetadata(runtimeMetadata?: ProviderRuntimeMetadata): {
        sessionId?: string;
        conversationId?: string;
    };
    static normalizeCodexClientHeaders(headers: Record<string, string> | undefined, codexUaMode: boolean): Record<string, string> | undefined;
    static ensureCodexSessionHeaders(headers: Record<string, string>, runtimeMetadata?: ProviderRuntimeMetadata): void;
    static extractClientHeaders(source?: Record<string, unknown> | ProviderRuntimeMetadata): Record<string, string> | undefined;
    private static buildCodexIdentifier;
    private static enforceCodexIdentifierLength;
}