LangChain

npm install @vane.build/langchain

import { VaneCallbackHandler } from '@vane.build/langchain';
import { ChatOpenAI } from '@langchain/openai';

const handler = new VaneCallbackHandler({
  baseUrl: process.env.VANE_URL!,
  apiKey: process.env.VANE_API_KEY!,
  agentId: 'researcher-1',
});

const llm = new ChatOpenAI({ callbacks: [handler] });
await llm.invoke('Summarise this contract.');

const llm = new ChatOpenAI({ callbacks: [handler] });

const executor = AgentExecutor.fromAgentAndTools({
  agent,
  tools,
  callbacks: [handler],
});

const chain = prompt.pipe(llm).withConfig({ callbacks: [handler] });

import { setGlobalCallbackManager } from '@langchain/core/callbacks/manager';
// Not recommended for production — attaches to every LangChain operation in the process.

import { VaneCallbackHandler } from '@vane.build/langchain';
import { createReactAgent } from '@langchain/langgraph/prebuilt';
import { ChatOpenAI } from '@langchain/openai';
import { tool } from '@langchain/core/tools';
import { z } from 'zod';

const handler = new VaneCallbackHandler({
  baseUrl: process.env.VANE_URL!,
  apiKey: process.env.VANE_API_KEY!,
  agentId: 'contract-reviewer',
  companyId: 'acme',
});

const searchTool = tool(
  async ({ query }) => `Results for: ${query}`,
  { name: 'search', description: 'Web search', schema: z.object({ query: z.string() }) },
);

const agent = createReactAgent({
  llm: new ChatOpenAI({ model: 'gpt-4o', callbacks: [handler] }),
  tools: [searchTool],
});

const result = await agent.invoke({
  messages: [{ role: 'user', content: 'Find the penalty clauses in EU AI Act.' }],
});