LangChain

pip install langchain-openai

npm install @langchain/openai

from langchain_openai import ChatOpenAI

llm = ChatOpenAI(
    base_url="https://kymaapi.com/v1",
    api_key="ky-your-api-key",
    model="qwen-3.6-plus",
)

import { ChatOpenAI } from "@langchain/openai";

const llm = new ChatOpenAI({
  configuration: { baseURL: "https://kymaapi.com/v1" },
  apiKey: "ky-your-api-key",
  model: "qwen-3.6-plus",
});

response = llm.invoke("Explain RAG in simple terms")
print(response.content)

const response = await llm.invoke("Explain RAG in simple terms");
console.log(response.content);

for chunk in llm.stream("Write a short story"):
    print(chunk.content, end="", flush=True)

const stream = await llm.stream("Write a short story");
for await (const chunk of stream) {
  process.stdout.write(chunk.content);
}

from langchain_core.prompts import ChatPromptTemplate

prompt = ChatPromptTemplate.from_messages([
    ("system", "You are a {role}."),
    ("user", "{question}")
])

chain = prompt | llm

response = chain.invoke({
    "role": "Python expert",
    "question": "How do decorators work?"
})
print(response.content)

import { ChatPromptTemplate } from "@langchain/core/prompts";

const prompt = ChatPromptTemplate.fromMessages([
  ["system", "You are a {role}."],
  ["user", "{question}"],
]);

const chain = prompt.pipe(llm);

const response = await chain.invoke({
  role: "Python expert",
  question: "How do decorators work?",
});
console.log(response.content);

from langchain_core.tools import tool

@tool
def get_weather(city: str) -> str:
    """Get weather for a city."""
    return f"Sunny, 72°F in {city}"

llm_with_tools = llm.bind_tools([get_weather])
response = llm_with_tools.invoke("What's the weather in Tokyo?")
print(response.tool_calls)

import { tool } from "@langchain/core/tools";
import { z } from "zod";

const getWeather = tool(
  async ({ city }) => `Sunny, 72°F in ${city}`,
  { name: "get_weather", description: "Get weather for a city", schema: z.object({ city: z.string() }) }
);

const llmWithTools = llm.bindTools([getWeather]);
const response = await llmWithTools.invoke("What's the weather in Tokyo?");
console.log(response.tool_calls);