/**
* A unique identifier for the current browser tab
* useful for observability/tracing and deduping
* across multiple tabs.
*
* @group Constants
*/
export declare const TAB_ID: string;
/**
* The epoch seconds at which the tab id was generated
*
* @group Constants
*/
export declare const TAB_ASSIGNED: number;
/**
* Adds the `X-Amzn-Trace-Id` header to support observability
* tooling around request routing.
*
* This makes use of the {@link TAB_ID} and {@link TAB_ASSIGNED}
* to enable tracking the browser tab of origin across multiple requests.
*
* Follows the template: `Root=1-${now}-${uuidv4};TabId=1-${epochSeconds}-${tab-uuid}`
*
* @group Utility Functions
*/
export declare function addTraceHeader(headers: Headers): Headers;
/**
* Source: https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/cloudfront-limits.html
* As of 2024-12-05 the maximum URL length is 8192 bytes.
*
* @group Constants
*/
export declare const MAX_URL_LENGTH = 8192;
/**
* This assertion takes a URL and throws an error if the URL is longer than the maximum URL length.
*
* See also {@link MAX_URL_LENGTH}
*
* @group Utility Functions
*/
export declare function assertInvalidUrlLength(url: string | undefined): void;