import { PipelineResult, Pipeline } from 'open-guardrail-core';

/**
 * Vercel AI SDK middleware-compatible interface.
 * Works with `experimental_middleware` in `generateText` / `streamText`.
 */
interface GuardrailMiddleware {
    /**
     * Transform params before sending to the model.
     * Runs input guards on the last user message.
     */
    transformParams?: (options: {
        params: LanguageModelParams;
    }) => Promise<LanguageModelParams>;
    /**
     * Wrap generate to run output guards on the response.
     */
    wrapGenerate?: (options: {
        doGenerate: () => Promise<GenerateResult>;
        params: LanguageModelParams;
    }) => Promise<GenerateResult>;
}
interface LanguageModelParams {
    prompt: Array<{
        role: string;
        content: string | Array<{
            type: string;
            text?: string;
        }>;
    }>;
    [key: string]: unknown;
}
interface GenerateResult {
    text?: string;
    [key: string]: unknown;
}
interface GuardrailMiddlewareOptions {
    input?: Pipeline;
    output?: Pipeline;
    onBlocked?: (result: PipelineResult, stage: 'input' | 'output') => void;
}
declare class GuardrailBlockedError extends Error {
    readonly stage: 'input' | 'output';
    readonly result: PipelineResult;
    constructor(stage: 'input' | 'output', result: PipelineResult);
}
declare function createGuardrailMiddleware(options: GuardrailMiddlewareOptions): GuardrailMiddleware;

export { GuardrailBlockedError, type GuardrailMiddleware, type GuardrailMiddlewareOptions, createGuardrailMiddleware };