/**
 * URI validation utilities.
 *
 * Provides RFC 3986 compliant URI validation including scheme validation
 * and extraction. These utilities are commonly used for validating resource URIs.
 */
/**
 * Validate that a URI has a valid scheme per RFC 3986.
 *
 * @param uri - The URI to validate
 * @returns true if the URI has a valid scheme, false otherwise
 *
 * @example
 * isValidMcpUri('file:///path/to/file') // true
 * isValidMcpUri('https://example.com/resource') // true
 * isValidMcpUri('custom://my-resource') // true
 * isValidMcpUri('/path/to/file') // false (no scheme)
 * isValidMcpUri('123://invalid') // false (scheme must start with letter)
 */
export declare function isValidMcpUri(uri: string): boolean;
/**
 * Extract the scheme from a URI.
 *
 * @param uri - The URI to extract the scheme from
 * @returns The scheme in lowercase, or null if no valid scheme found
 *
 * @example
 * extractUriScheme('file:///path') // 'file'
 * extractUriScheme('HTTPS://example.com') // 'https'
 * extractUriScheme('/no/scheme') // null
 */
export declare function extractUriScheme(uri: string): string | null;
/**
 * Validate that a URI template has a valid scheme per RFC 3986.
 * URI templates follow RFC 6570 and can contain template expressions like {var}.
 * The scheme portion should still be a valid static scheme.
 *
 * @param uriTemplate - The URI template to validate
 * @returns true if the URI template has a valid scheme, false otherwise
 *
 * @example
 * isValidMcpUriTemplate('users://{userId}/profile') // true
 * isValidMcpUriTemplate('file:///{path}') // true
 * isValidMcpUriTemplate('{scheme}://dynamic') // false (scheme must be static)
 */
export declare function isValidMcpUriTemplate(uriTemplate: string): boolean;