LangChain

Point langchain-openai's base_url at TokRouter and use any gateway model inside LangChain.

LangChain's OpenAI integration accepts a custom base_url — point it at the gateway.

pip install langchain-openai

import os
from langchain_openai import ChatOpenAI

llm = ChatOpenAI(
    model="gpt-5.4-mini",
    api_key=os.environ["TOKROUTER_API_KEY"],
    base_url="https://api.tokrouter.dev/v1",
)

print(llm.invoke("Explain RAG in one sentence").content)

Mixing vendors in one chain

planner = ChatOpenAI(
    model="claude-opus-5-5",
    api_key=os.environ["TOKROUTER_API_KEY"],
    base_url="https://api.tokrouter.dev/v1",
)
worker = ChatOpenAI(
    model="deepseek-v4-flash",
    api_key=os.environ["TOKROUTER_API_KEY"],
    base_url="https://api.tokrouter.dev/v1",
)

plan = planner.invoke("Split 'refactor the login module' into three steps; output only the list").content
print(worker.invoke(f"Write the implementation notes for step one:\n{plan}").content)

Streaming and tools

stream() and bind_tools() use the same OpenAI protocol fields, and the gateway behaves identically. Tool-use support varies by model — see Tool calling.

Mixing vendors in one chain

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