LangChain และ LlamaIndex กับโมเดล open-weight

import os

from langchain_openai import ChatOpenAI

llm = ChatOpenAI(
    model="deepseek-v4-pro",
    base_url="https://llmwithcrypto.com/api/v1",
    api_key=os.environ["LLMWITHCRYPTO_API_KEY"],
    max_tokens=300,
    temperature=0.3,
)
reply = llm.invoke("Explain what a vector database is in two sentences.")
print(reply.content)
print(reply.usage_metadata)

import os

from langchain_core.tools import tool
from langchain_openai import ChatOpenAI


@tool
def convert_currency(amount: float, rate: float) -> float:
    """Convert an amount with an exchange rate."""
    return round(amount * rate, 2)


llm = ChatOpenAI(
    model="gpt-oss-120b",
    base_url="https://llmwithcrypto.com/api/v1",
    api_key=os.environ["LLMWITHCRYPTO_API_KEY"],
)
llm_with_tools = llm.bind_tools([convert_currency])
msg = llm_with_tools.invoke("How much is 250 at a rate of 0.92?")
for call in msg.tool_calls:
    print(call["name"], call["args"], "->", convert_currency.invoke(call["args"]))

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

const llm = new ChatOpenAI({
  model: 'qwen3-235b-a22b-instruct-2507',
  apiKey: process.env.LLMWITHCRYPTO_API_KEY,
  configuration: { baseURL: 'https://llmwithcrypto.com/api/v1' },
  maxTokens: 300,
});
const reply = await llm.invoke('Give me a three-step plan to learn SQL.');
console.log(reply.content);

import os

from llama_index.llms.openai_like import OpenAILike

llm = OpenAILike(
    model="deepseek-v4.1-flash",
    api_base="https://llmwithcrypto.com/api/v1",
    api_key=os.environ["LLMWITHCRYPTO_API_KEY"],
    is_chat_model=True,
    context_window=131072,
    max_tokens=300,
)
print(llm.complete("Name three uses of a knowledge graph."))