LangChain

LangChain + TheRouter.ai for Python and TypeScript

LangChain's OpenAI integrations can target TheRouter.ai by changing base URL and model IDs, enabling quick migration without chain rewrites.

Overview

This page mirrors the OpenRouter workflow and adapts it for TheRouter.ai. Use TheRouter.ai as your OpenAI-compatible endpoint and keep model IDs in `provider/model` format.

Installation

Install the required SDKs and keep your TheRouter.ai key in environment variables.

install.sh

npm install @langchain/openai @langchain/core && pip install langchain-openai

Configuration

Set TheRouter.ai base URL overrides and pass your API key. Add attribution headers when your app should appear in rankings.

TypeScript

const llm = new ChatOpenAI({
  model: "anthropic/claude-sonnet-4.5",
  apiKey: process.env.THEROUTER_API_KEY,
  configuration: { baseURL: "https://api.therouter.ai/v1" },
});

Caveats

Integration note

LangChain retries can stack with TheRouter.ai fallback retries. Tune retry counts to avoid excessive tail latency.

For production rollouts, pin SDK versions and validate model compatibility in staging before broad rollout.