Quickstart

curl https://gateway.smith.langchain.com/openai/v1/chat/completions \
    -H "Authorization: Bearer $LANGSMITH_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{"model":"gpt-4o-mini","messages":[{"role":"user","content":"ping"}]}'

import os

from openai import OpenAI

client = OpenAI(
    base_url=os.environ["OPENAI_BASE_URL"],
    api_key=os.environ["LANGSMITH_API_KEY"],
)
response = client.chat.completions.create(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "ping"}],
)
print(response.choices[0].message.content)

import os

import anthropic

client = anthropic.Anthropic(
    base_url=os.environ["ANTHROPIC_BASE_URL"],
    api_key=os.environ["LANGSMITH_API_KEY"],
)
message = client.messages.create(
    model="claude-sonnet-4-6",
    max_tokens=1024,
    messages=[{"role": "user", "content": "ping"}],
)
print(message.content[0].text)

import os

from langchain.agents import create_agent
from langchain.chat_models import init_chat_model

# Anthropic shown here; OpenAI and Gemini are also supported by swapping base_url and model_provider.
model = init_chat_model(
    model="claude-sonnet-4-6",
    model_provider="anthropic",
    base_url=os.environ["ANTHROPIC_BASE_URL"],
    api_key=os.environ["LANGSMITH_API_KEY"],
)
agent = create_agent(model=model, system_prompt="You are a helpful assistant.")
result = agent.invoke({"messages": [{"role": "user", "content": "ping"}]})
print(result["messages"][-1].content)