import type { SpendGuard } from '../spend-guard';
import { type FrameworkAdapterOptions } from './common';
/**
 * LangChain.js callback handler that runs `guard.decide()` before every LLM /
 * chat-model call and settles real token usage after it completes.
 *
 * Hook point: LangChain's `BaseCallbackHandler` lifecycle methods
 * `handleChatModelStart` / `handleLLMStart` (preflight, may throw
 * AgentGuardBlockedError) and `handleLLMEnd` (usage settlement). We do NOT
 * extend the real BaseCallbackHandler (that would force a peer-dep import at
 * module load); LangChain duck-types handlers by these method names, and we set
 * `awaitHandlers = true` so a thrown block aborts the call.
 *
 * This adapter reuses the shared framework core (createFrameworkGuard +
 * preflightFrameworkCall + settleFrameworkCall). It never proxies prompts,
 * completions, or provider keys — only redacted request shape leaves for the
 * signed receipt.
 *
 * @example
 *   import { ChatOpenAI } from '@langchain/openai';
 *   import { createLangChainHandler } from '@agentguard-run/spend/frameworks/langchain';
 *
 *   const handler = createLangChainHandler({ policy, scope });
 *   const llm = new ChatOpenAI({ callbacks: [handler] });
 *   await llm.invoke('hello'); // throws AgentGuardBlockedError if a cap blocks
 */
export interface LangChainAdapterOptions extends FrameworkAdapterOptions {
    framework?: 'langchain';
}
interface LangChainSerialized {
    id?: string[];
    kwargs?: Record<string, unknown>;
    [key: string]: unknown;
}
export declare class AgentGuardLangChainHandler {
    readonly name = "agentguard_spend";
    /** Ensures LangChain awaits the handler so a thrown block actually aborts. */
    readonly awaitHandlers = true;
    readonly guard: SpendGuard;
    private readonly opts;
    private readonly pending;
    constructor(opts: LangChainAdapterOptions);
    handleChatModelStart(llm: LangChainSerialized, messages: unknown[][], runId: string, _parentRunId?: string, extraParams?: Record<string, unknown>, _tags?: string[], metadata?: Record<string, unknown>): Promise<void>;
    handleLLMStart(llm: LangChainSerialized, prompts: unknown[], runId: string, _parentRunId?: string, extraParams?: Record<string, unknown>, _tags?: string[], metadata?: Record<string, unknown>): Promise<void>;
    handleLLMEnd(output: unknown, runId: string): Promise<void>;
    handleLLMError(_error: unknown, runId: string): Promise<void>;
    private start;
}
export declare function createLangChainHandler(opts: LangChainAdapterOptions): AgentGuardLangChainHandler;
export declare const agentguardLangChainHandler: typeof createLangChainHandler;
export {};
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