/** Phantom brand carrying an extension type without emitting runtime code. */
declare const extensionTokenType: unique symbol;
/**
 * A typed stable name for resolving an installed extension.
 *
 * Tokens are plain strings at runtime, so independently compiled scripts can
 * share them without a registry or object-identity contract. The generic brand
 * lets `Client.getExtension` infer the extension type. A token's string
 * value must exactly match its extension's stable `name`.
 */
export type ExtensionToken<T> = string & {
    readonly [extensionTokenType]: T;
};
export {};