Use the Claude API with LangChain
LangChain's Anthropic integration accepts a custom API URL, so your chains and agents can run on Claude through apiToken.sale with a two-line change — same models, lower token price.
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Point ChatAnthropic at the gateway
from langchain_anthropic import ChatAnthropic
llm = ChatAnthropic(
model="claude-opus-4-8",
anthropic_api_url="https://api.apitoken.sale",
anthropic_api_key="sk-pool-•••",
)
print(llm.invoke("Hello").content)That is the whole integration: the same langchain-anthropic package, the same model IDs, the same streaming and tool-calling — only the endpoint and the price change.
See also: Point the Anthropic SDK at apiToken.sale
Or configure via environment variables
export ANTHROPIC_API_URL=https://api.apitoken.sale export ANTHROPIC_API_KEY=sk-pool-•••
With the environment set, ChatAnthropic picks up both values automatically, so shared codebases need no code change at all.
What works
- Chains, agents and LangGraph workflows — the protocol is unchanged.
- Streaming, tool calling and structured output through the standard integration.
- Every supported Claude model (Opus, Sonnet, Haiku) on one key and balance.
Frequently asked questions
Does LangChain work with a custom Claude API endpoint?
Yes. ChatAnthropic accepts anthropic_api_url (or the ANTHROPIC_API_URL environment variable), so you can point it at https://api.apitoken.sale and keep everything else unchanged.
Do LangChain agents and tool calling still work?
Yes — the gateway serves the standard Anthropic Messages API, so tool calling, streaming and LangGraph agents behave exactly as with the official endpoint.
Which models can I use from LangChain?
All supported Claude models — claude-opus-4-8, claude-sonnet-5, claude-haiku-4-5 and more — on the same key and prepaid balance.
Try it before you pay: new Google/GitHub accounts include $10 of official-price Claude usage.