import { ChatMiddleware } from './activities/chat/middleware/types.js';
import { StreamChunk } from './types.js';
/**
 * Strip only the deprecated nested `error` object from RUN_ERROR events.
 * The flat `message`/`code` fields are the spec-compliant form.
 *
 * All other fields pass through unchanged. @ag-ui/core's BaseEventSchema
 * uses `.passthrough()`, so extra fields (model, content, usage,
 * finishReason, toolName, stepId, etc.) are allowed and won't break
 * spec validation or verifyEvents.
 */
export declare function stripToSpec(chunk: StreamChunk): StreamChunk;
/**
 * Middleware that ensures events are AG-UI spec compliant.
 * Currently only strips the deprecated nested `error` object from RUN_ERROR.
 * All other fields pass through unchanged (passthrough allowed by spec).
 */
export declare function stripToSpecMiddleware(): ChatMiddleware;