/**
 * Parse Hermes-style `required_environment_variables` and legacy / xopc `requires.env` into a deduped name list.
 */
/** POSIX-style env var names we allow for passthrough registration. */
export declare const SKILL_ENV_VAR_NAME_RE: RegExp;
export declare function isValidSkillEnvVarName(name: string): boolean;
export declare function parseRequiredEnvVarNames(frontmatter: Record<string, unknown>): string[];