import { CapabilityHandle } from './capabilities.js';
import { ChatMiddleware } from './types.js';
/**
 * A middleware whose `requires`/`provides` tuple types are captured precisely
 * (via `const` inference) for the array coverage check and the builder.
 */
export interface DefinedChatMiddleware<TContext, TRequires extends ReadonlyArray<CapabilityHandle>, TProvides extends ReadonlyArray<CapabilityHandle>> extends ChatMiddleware<TContext> {
    requires?: TRequires;
    provides?: TProvides;
}
/**
 * Identity helper for authoring middleware with precise capability inference.
 * Returns the middleware unchanged at runtime; only sharpens its type so the
 * `chat()` array coverage check and `createChatMiddleware` builder can read the
 * exact `requires`/`provides`.
 */
export declare function defineChatMiddleware<TContext = unknown, const TRequires extends ReadonlyArray<CapabilityHandle> = readonly [], const TProvides extends ReadonlyArray<CapabilityHandle> = readonly []>(middleware: ChatMiddleware<TContext> & {
    requires?: TRequires;
    provides?: TProvides;
}): DefinedChatMiddleware<TContext, TRequires, TProvides>;