import { type McpServerLayer } from './env-containment.js';
export interface EnvExpansionResult<T> {
    value: T;
    missing: string[];
    blocked: string[];
}
export declare function expandEnvString(input: string, source?: NodeJS.ProcessEnv): Omit<EnvExpansionResult<string>, 'blocked'>;
export declare function expandEnvRecord(input: Record<string, string> | undefined, source?: NodeJS.ProcessEnv): Omit<EnvExpansionResult<Record<string, string>>, 'blocked'>;
export interface EnvExpansionContext {
    layer: McpServerLayer;
    serverName: string;
    allowSecretEnv?: readonly string[];
}
export declare function expandEnvStringForLayer(input: string, ctx: EnvExpansionContext, source?: NodeJS.ProcessEnv, warn?: (msg: string) => void): EnvExpansionResult<string>;
export declare function expandEnvRecordForLayer(input: Record<string, string> | undefined, ctx: EnvExpansionContext, source?: NodeJS.ProcessEnv, warn?: (msg: string) => void): EnvExpansionResult<Record<string, string>>;
export declare function expandHeadersForLayer(headers: Record<string, string> | undefined, ctx: EnvExpansionContext, source?: NodeJS.ProcessEnv, warn?: (msg: string) => void): {
    headers: Record<string, string>;
    missing: string[];
    blocked: string[];
};