/**
 * @file HTTP header sanitization utilities for secure logging. Provides
 *   functions to redact sensitive header values from logs.
 */
/**
 * Coerce one header value to a string without ever throwing. `String(value)`
 * throws a TypeError on an object with a non-callable `toString` and no
 * `Symbol.toPrimitive`; sanitized headers feed diagnostics/logging, which is
 * never worth an exception.
 */
export declare function coerceHeaderValue(value: unknown): string;
/**
 * List of sensitive HTTP headers that should be redacted in logs.
 */
export declare const SENSITIVE_HEADERS: readonly string[];
/**
 * Sanitize headers for logging by redacting sensitive values.
 *
 * @param headers - Headers to sanitize (object or array)
 *
 * @returns Sanitized headers with sensitive values redacted
 */
export declare function sanitizeHeaders(headers: Record<string, unknown> | readonly string[] | undefined): Record<string, string> | undefined;