import type { PayloadType } from './generated/protocol.js';
export type InputValidationIssue = {
    readonly path: string;
    readonly code: 'TYPE_MISMATCH' | 'MISSING_REQUIRED_FIELD' | 'UNKNOWN_FIELD' | 'UNKNOWN_ENUM_LABEL';
};
/** Return the first deterministic schema issue without retaining the input value. */
export declare function firstInputValidationIssue(type: PayloadType, value: unknown, path?: string): InputValidationIssue | null;
export declare function assertInputValue(type: PayloadType, value: unknown): void;