LangChain

Name: LangChain
Author: LangChain

by LangChainFramework / SDKlangchain.com

LangChain composes models, tools, memory and retrieval into chains and agents in Python and TypeScript. Give its OpenAI chat model Opper's base URL and an Opper key, and everything downstream of the model, including the tools, the retrievers and the agent loop, stays exactly as you wrote it, while the model itself becomes any of 700+ on one key.

Build with LangChain on Opper

LangChain reaches Opper over the OpenAI-compatible endpoint. Point it at https://api.opper.ai/v3/compat with your Opper key and pick a model.

Get your API key

In your code

1import os
2
3from langchain_openai import ChatOpenAI
4
5llm = ChatOpenAI(
6    model="anthropic/claude-fable-5",
7    base_url="https://api.opper.ai/v3/compat",
8    api_key=os.environ["OPPER_API_KEY"],
9)

More apps on Opper

Mastra

Opper is a provider in Mastra's model router. Write a model string, set a key, and the agent runs through the gateway.

FrameworksOpper built in

Vercel AI SDK

Our provider for the Vercel AI SDK, so generateText, streamText and tool calls run on any model behind one key.

Frameworks@opperai/ai-sdk-provider

LiteLLM

Reach Opper through LiteLLM's OpenAI-compatible provider, in the Python SDK or behind the proxy.

Frameworks/v3/compat